marlin tft display supplier

I was rebuilding one of my 3D printers — again — and decided I needed a display upgrade. A color screen is nice, but there are some limitations. I also found there are ways around these limitations, so I wanted to share my thoughts on a dual-mode color touch screen LCD controller for your 3D printer. The screen in question is a TFT35 from BigTree Tech. It is similar to an MKS screen, but it can operate in two different modes, as you will see.

A few years ago, I picked up an Anet A8 which was very inexpensive, especially on sale. Not the best printer, though, because it has that cheap acrylic frame. No problem. A box full of aluminum extrusion later, the printer was reborn. Over time, I’ve completely reworked the extrusion system and the Y-axis, leaving only the motors, bearings, and the controller/display as the original.

I happened to have one of these lying around so when I installed a new motherboard — a Fysetc Spider if you are curious — I also wired in the new LCD. I had to recompile Marlin, of course, but that’s easy. It all worked, it just looked a little bland.

There’s another way to control a printer, and it’s one you may have thought of before. Since the printer accepts commands via a serial port, you could take a computer like a Raspberry Pi with a nice LCD and just have it issue commands to the serial port. Bonus points if the board has more than one serial port so you can still hook up a PC or a Raspberry Pi running Octoprint or similar. Turns out, you don’t have to build this. The MKS touchscreen uses an ARM chip (it isn’t a Pi, though) and has a touch screen that you can use to control the printer. These come in different sizes and are usually called something like TFT35 for 3.5 inch display.

The advantage isn’t just appearance. Having a bunch of touch screen buttons makes many things easier. For example, if the printer is at (0,0) and you want to jog the head to (100,200), that ends up being a lot of button pushes in Marlin. With the touch display, you can bring up a navigation screen that makes it easy. Or, you can bring up an entire terminal and enter G-code. When you press Send, it shows the results of the command, if any. You can set a temperature with the knob, on-screen buttons, or press the number and type in what you want with a virtual keypad.

These displays are colorful and nice, but there are a few things they can’t do. Marlin has some wizards and user interaction that insist on a proper, local LCD. But the Marlin code thinks the MKS display is a remote host computer, connected over serial. Displays that can act like both types of LCDs are a sweet hack, and here’s the part that was never clear to me before: these displays can switch modes during printer operation. In other words, it is not a case of selecting a mode and rebooting everything. You can be looking at the colorful touchscreen, then switch over to the stock display while printing and then switch back any time you want. The best of both worlds.

On the face of it, the display looks like an MKS TFT. You have colorful menus and a touch screen. The connection for that is a simple two-wire serial port, along with — of course — power, ground, and an optional reset connection. They provide a cable you can use or modify to connect to your setup. There is also an EXT3 port for boards that have that connector.

If all you want is an MKS display, you are done. Since the display looks like a host computer, you don’t even have to recompile Marlin if the serial port you used was active. In my case, the second serial port wasn’t set up, so I had to recompile, but I do that often enough, anyway.

However, if you wire the normal EXT1 and EXT2 ribbon cables to your printer, the display can emulate a normal 128×64 LCD. If you are already set up to use one of these displays, you should not need to recompile Marlin to use this display. However, if you are set up for a different type of display, you’ll need to tell Marlin to use the normal “REPRAP DISCOUNT GRAPHICS CONTROLLER.”

Here’s what I never understood about the device. Looking at the write-up about it on different vendor sites like Amazon, Banggood, or AliExpress, it sounded like you could use the screen in either mode as a static configuration choice. In other words, you might wire up EXT1 and EXT2 and then use the emulated mode until you decided to switch over to serial at some future date. But that’s not how it works. You can connect all the cables and switch back and forth between display systems on the fly.

That’s huge. It means you can have a nice user interface that lets you control the printer, print from an SD card or USB stick, and even make customizations to the menu with the source code provided on GitHub or with a simple configuration file edit. (And, yes, you can add custom menu items simply.) But when you need to do something very specific to Marlin, or a new feature shows up that the LCD doesn’t know about yet, you can simply switch to the Marlin display mode. Then you can switch back.

The process to switch is simple. Just hold down the encoder knob or push the screen for a few seconds. A screen will show up allowing you to pick the Marlin mode or the BTT mode. Just touch the one you want. In Marlin mode, the touchscreen does nothing except switch modes, so you might want to use that method. If you hold the encoder down in Marlin mode, the printer will also see the repeated enter keys until the LCD pops up the selection screen.

Installing the LCD was straightforward save a few problems. For some reason, the pin 1 designation for EXP1 and EXP2 are not consistent among vendors. A Geeetech display worked fine with the Spider board, but the TFT35 didn’t want to come up in Marlin mode at all. I applied power at the serial port and the board appeared hung. The answer was to snip off the alignment tabs on the ribbon cables and flip them 180 degrees.

The serial port was also a mystery. With so little documentation on anything, I just soldered the power and ground wires and then hand twisted RX and TX so I could swap them until it worked. As I expected, the cable needed a cross on those lines to work. You also have to match the display’s baud rate to the port you are using.

After that, it all worked fine. The EXP1 and EXP2 connectors do connect to the board’s reset, so you don’t need to wire the serial port’s reset pin if you have those connected. However, I did notice that switching the mainboard to DFU mode will sometimes fail with the display plugged in. Reflashing the display requires an SD card that flashes a binary file and then reboots and loads fonts and icons. If it is connected to the Spider, it sometimes hangs when trying to reboot during an update. It also works sometimes, though, so I suspect it is just loading on the reset line. In any event, popping the connectors will make it work if you don’t want to try repeatedly.

The display has a number of other ports, but you probably shouldn’t use them. For example, there’s a port for a filament runout sensor. But if you connect it there, it will only work if you are printing using an SD card or USB stick in the display. A better option is to connect it to your printer and tell Marlin to notify the host if a filament break occurs. This will work with the display or something like Octoprint.

In theory, you should be able to connect Octoprint itself through one of the extra serial ports. However, I never got this to fully work. The subordinate port seems to work pretty well, but it never sends Octoprint acknowledgments so Octoprint waits forever or until you force it to continue — use the Fake Acknowledgment button in the terminal. Since the Spider has multiple serial ports, it isn’t a big deal, but in theory, the TFT should work a little better if it can intercept and filter the data stream between the printer and the host software. In practice, I don’t really notice any problems. Some Octoprint plugins like DisplayLayer can send status information to the TFT, anyway.

The truth is, I don’t switch over to Marlin mode very often, but it is nice to have it if I want it, and you can even change the colors to suit you. I really wanted the passthrough mode to work but couldn’t figure out what was going on without digging into the source code, and that might be a project for another day.

Another note: Using the jog keys sets the printer to relative mode. If you are used to popping codes into a terminal, you might want to get used to issuing a G90 before you send a move because the TFT will change it to relative anytime you do a jog.

These displays are inexpensive and easy to interface and since they can still work as a classic display, there’s no reason not to do this easy upgrade. There are plenty of mounting options you can print, of course. The finished result looks great and doing things like moving in both X and Y are much easier with the new display.

https://github.com/nopnop2002/wiringpi-tft-tool/blob/6f0f91fed2d5a07f1e62663eb8bc37458c11bb65/8bitlib.c

variants 5 :LCD is inverted,writings are mirrored and in info screen touch has some problems for example when i touched fan, nozzle 1 setting were displayed and when i touched nozzle 2 fan setting were displayed.

// https://www.aliexpress.com/item/Micromake-Makeboard-3D-Printer-Parts-3D-Printer-Mini-Display-1602-Mini-Controller-Compatible-with-Ramps-1/32765887917.html

TFT displays are full color LCDs providing bright, vivid colors with the ability to show quick animations, complex graphics, and custom fonts with different touchscreen options. Available in industry standard sizes and resolutions. These displays come as standard, premium MVA, sunlight readable, or IPS display types with a variety of interface options including HDMI, SPI and LVDS. Our line of TFT modules include a custom PCB that support HDMI interface, audio support or HMI solutions with on-board FTDI Embedded Video Engine (EVE2).

Marlin is a huge C++ program composed of many files, but here we’ll only be talking about the two files that contain all of Marlin’s compile-time configuration options: Configuration.h contains the core settings for the hardware, language and controller selection, and settings for the most common features and components.

The two .h files contain all of Marlin’s build-time configuration options. Simply edit or replace these files, then build and upload Marlin to the board. Hundreds of user-donated configurations are posted at the Configurations repository to get you started.

Marlin is configured using C++ compiler directives. This allows Marlin to leverage the C++ preprocessor and include only the code and data needed for the enabled options. This results in the smallest possible binary. A build of Marlin can range from 50K to over 230K in size.

To use configurations from an earlier version of Marlin, first try dropping them into the newer Marlin, updating CONFIGURATION_H_VERSION and CONFIGURATION_ADV_H_VERSION, and building the firmware. As part of the build process, Marlin’s sanity-checking prints out helpful error messages explaining what needs to change.

The core and default settings of Marlin live in the Configuration.h file. Most of these settings are fixed. Once you compile Marlin, that’s it. To change them you need to re-compile. However, several items in Configuration.h only provide defaults -factory settings- that can be changed via the user interface, stored on EEPROM and reloaded or restored to initial values.

Marlin now checks for a configuration version and won’t compile without this setting. If you want to upgrade from an earlier version of Marlin, add this line to your old configuration file. During compilation, Marlin will throw errors explaining what needs to be changed.

#define CUSTOM_STATUS_SCREEN_IMAGE STRING_CONFIG_H_AUTHOR is shown in the Marlin startup message to identify the author (and optional variant) of the firmware. Use this setting as a way to uniquely identify your custom configurations. The startup message is printed whenever the board (re)boots.

The most important setting is Marlin is the motherboard. The firmware needs to know what board it will be running on so it can assign the right functions to all pins and take advantage of the full capabilities of the board. Setting this incorrectly will lead to unpredictable results.

This is the name of your printer as displayed on the LCD and by M115. For example, if you set this to “My Delta” the LCD will display “My Delta ready” when the printer starts up.

This value, from 0 to 6, defines how many extruders (or E steppers) the printer has. By default Marlin will assume separate nozzles all moving together on a single carriage. If you have a single nozzle, a switching extruder, a mixing extruder, or dual X carriages, specify that below.

This value is used by Marlin to compensate for Filament Width when printing in volumetric mode (See M200), and by the Unified Bed Leveling command G26 when printing a test grid.

The listing above these options in Configuration.h contains all the thermistors and thermocouples that Marlin knows and supports. Try to match your brand and model with one of the sensors in the list. If no match is found, use a profile for a similar sensor of the same brand, or try “1” – the generic profile. Each profile is calibrated for a particular temperature sensor so it’s important to be as precise as possible.

Enable this option to use sensor 1 as a redundant sensor for sensor 0. This is an advanced way to protect against temp sensor failure. If the temperature difference between sensors exceeds MAX_REDUNDANT_TEMP_SENSOR_DIFF Marlin will abort the print and disable the heater.

Maximum temperature for each temperature sensor. If Marlin reads a temperature above these values, it will immediately shut down for safety reasons. For the E3D V6 hotend, many use 285 as a maximum value.

Marlin uses PID (Proportional, Integral, Derivative) control (Wikipedia) to stabilize the dynamic heating system for the hotends and bed. When PID values are set correctly, heaters reach their target temperatures faster, maintain temperature better, and experience less wear over time.

Thermal protection is one of the most vital safety features in Marlin, allowing the firmware to catch a bad situation and shut down heaters before it goes too far. Consider what happens when a thermistor comes loose during printing. The firmware sees a low temperature reading so it keeps the heat on. As long as the temperature reading is low, the hotend will continue to heat up indefinitely, leading to smoke, oozing, a ruined print, and possibly even fire.

Marlin offers two levels of thermal protection: Check that the temperature is actually increasing when a heater is on. If the temperature fails to rise enough within a certain time period (by default, 2 degrees in 20 seconds), the machine will shut down with a “Heating failed” error. This will detect a disconnected, loose, or misconfigured thermistor, or a disconnected heater.

Marlin supports four kinematic motion systems: Cartesian, Core (H-Bot), Delta, and SCARA. Cartesian is the simplest, applying each stepper directly to an axis. CoreXY uses a special belt arrangement to do XY motion, requiring a little extra maths. Delta robots convert the motion of three vertical carriages into XYZ motion in an “effector” attached to the carriages by six arms. SCARA robots move an arm in the XY plane using two angular joints.

These settings allow Marlin to tune stepper driver timing and enable advanced options for stepper drivers that support them. You may also override timing options in Configuration_adv.h.

In print/travel moves, DEFAULT_ACCELERATION and DEFAULT_TRAVEL_ACCELERATION apply to the XYZ axes. In retraction moves, DEFAULT_RETRACT_ACCELERATION applies only to the E-axis. During movement planning, Marlin constrains the default accelerations to the maximum acceleration of all axes involved in the move.

Use this option if you’ve connected the probe to a pin other than the Z MIN endstop pin. With this option enabled, by default Marlin will use the Z_MIN_PROBE_PIN specified in your board’s pins file (usually the X or Z MAX endstop pin since these are the most likely to be unused). If you need to use a different pin, define your custom pin number for Z_MIN_PROBE_PIN in Configuration.h.

With Marlin you can directly specify the bed size. This allows Marlin to do extra logic related to the bed size when it differs from the movement limits below. If the XY carriage is able to move outside of the bed, you can specify a wider range below.

With this feature, a mechanical or opto endstop switch is used to check for the presence of filament in the feeder (usually the switch is closed when filament is present). If the filament runs out, Marlin will run the specified G-code script (by default M600).

If you have SRAM to spare, this option will multiply the resolution of the bilinear grid using the Catmull-Rom subdivision method. This option only applies to bilinear leveling. If the default value of 3 is too expensive, try 2 or 1. (In Marlin 1.1.1, the default grid will be stored in PROGMEM, as UBL now does.)

Commands like M92 only change the settings in volatile memory, and these settings are lost when the machine is powered off. With this option enabled, Marlin uses the built-in EEPROM to preserve settings across reboots. Settings saved to EEPROM (with M500) are loaded automatically whenever the machine restarts (and in most setups, when connecting to a host), overriding the defaults set in the configuration files. This option is highly recommended, as it makes configurations easier to manage.

When Host Keepalive is enabled Marlin will send a busy status message to the host every couple of seconds when it can’t accept commands. Disable if your host doesn’t like keepalive messages. Use DEFAULT_KEEPALIVE_INTERVAL for the default number of seconds between “busy” messages. Override with M113. Marlin 1.1.5 and up include the BUSY_WHILE_HEATING option for hosts that treat host keepalive as a strict busy protocol.

This option applies only to character-based displays. Character-based displays (based on the Hitachi HD44780) provide an ASCII character set plus one of the following language extensions: JAPANESE … the most common

Disable all menus and only display the Status Screen with NO_LCD_MENUS, or just remove some extraneous menu items to recover space with SLIM_LCD_MENUS.

Marlin includes support for several controllers. The two most popular controllers supported by Marlin are: REPRAP_DISCOUNT_SMART_CONTROLLER A 20 x 4 character-based LCD controller with click-wheel.

REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER A monochrome 128 x 64 pixel-based LCD controller with click-wheel. Able to display simple bitmap graphics and up to 5 lines of text.

Temperature status LEDs that display the hotend and bed temperature. If all hotend and bed temperature set-point are < 54C then the BLUE led is on. Otherwise the RED led is on. There is 1C hysteresis.

Marlin includes support for the Baricuda Extruder for 3D Printing Sugar and Chocolate also hosted on GitHub. The feature adds the codes M126, M127, M128, and M129 for controlling the pump and valve of the Baricuda.

Marlin currently supplies two options for RGB-addressable color indicators. In both cases the color is set using M150 Rr Ug Bb to specify RGB components from 0 to 255.

#define NEOPIXEL_PIXELS 30 // Number of LEDs in the strip, larger of 2 strips if 2 NeoPixel strips are used #define NEOPIXEL_IS_SEQUENTIAL // Sequential display for temperature change - LED by LED. Disable to change all LEDs at once. #define NEOPIXEL_BRIGHTNESS 127 // Initial brightness (0-255) //#define NEOPIXEL_STARTUP_TEST // Cycle through colors at startup

To solve this issue, this option sets the number of milliseconds a hotend will preheat before Marlin starts to check the temperature. Set a delay sufficient to reach a temperature your sensor can reliably read. Lower values are better and safer. If you require a value over 30000, this could indicate a problem.

#if EITHER(ULTIPANEL, EXTENSIBLE_UI) #define MANUAL_FEEDRATE { 50*60, 50*60, 4*60, 60 } // Feedrates for manual moves along X, Y, Z, E from panel #define SHORT_MANUAL_Z_MOVE 0.025 // (mm) Smallest manual Z move (< 0.1mm) #if ENABLED(ULTIPANEL) #define MANUAL_E_MOVES_RELATIVE // Display extruder move distance rather than "position" #define ULTIPANEL_FEEDMULTIPLY // Encoder sets the feedrate multiplier on the Status Screen #endif

#if ENABLED(LED_CONTROL_MENU) #define LED_COLOR_PRESETS // Enable the Preset Color menu option #if ENABLED(LED_COLOR_PRESETS) #define LED_USER_PRESET_RED 255 // User defined RED value #define LED_USER_PRESET_GREEN 128 // User defined GREEN value #define LED_USER_PRESET_BLUE 0 // User defined BLUE value #define LED_USER_PRESET_WHITE 255 // User defined WHITE value #define LED_USER_PRESET_BRIGHTNESS 255 // User defined intensity //#define LED_USER_PRESET_STARTUP // Have the printer display the user preset color on startup

Use the optimizations here to improve printing performance, which can be adversely affected by graphical display drawing, especially when doing several short moves, and when printing on DELTA and SCARA machines.

Some of these options may result in the display lagging behind controller events, as there is a trade-off between reliable printing performance versus fast display updates.

This feature allows Marlin to use linear pressure control for print extrusion, to eliminate ooze, improve corners, etc. See Configuration_adv.h and the Linear Advance page for more complete documentation.

Some hosts use a proportional font in their output console. This makes it hard to read output from Marlin that relies on fixed-width for alignment. This option tells Marlin how many spaces are required to fill up a typical character space in the host font. For clients that use a fixed-width font (like OctoPrint), leave this set to 1.0. Otherwise, adjust according to your host.

Experimental feature for filament change support and parking the nozzle when paused. Adds the M600 command to perform a filament change. With PARK_HEAD_ON_PAUSE enabled also adds the M115 command to pause printing and park the nozzle. Requires an LCD display. Note that M600 is required for the default FILAMENT_RUNOUT_SCRIPT. Requires LCD display and NOZZLE_PARK_FEATURE.

You’ll need to import the L6470 library into the Arduino IDE for this. See Configuration_adv.h for the full set of sub-options. NOTE: Support for L6470 was removed from Marlin in version 2.1, but may be restored in a future version if there is some demand.

This feature can be used to talk to slave devices on the i2c bus, passing data back to the host. With additional work the TWIBus class can be used to build a full protocol and add remote control features to Marlin, distributing load over two or more boards.

SuperPid is a router/spindle speed controller used in the CNC milling community. Marlin can be used to turn the spindle on and off. It can also be used to set the spindle speed from 5,000 to 30,000 RPM.

Enable to add support for a filament width sensor such as Filament Width Sensor Prototype Version 3. With a filament sensor installed, Marlin can adjust the flow rate according to the measured filament width. Adjust the sub-options below according to your setup.

It is recommended to enable this feature (along with EXTENDED_CAPABILITIES_REPORT) to install the M155 Auto-Report Temperature command. M115 tells Marlin to send the current temperature to the host at regular intervals, instead of requiring the host software to send M105 repeatedly. This saves a space in the command buffer and reduces overhead.

Enable this option for a leaner build of Marlin that removes all workspace offsets. This simplifies all coordinate transformations, leveling, etc., and may allow for slightly faster printing. With this option, M206 and M428 are disabled, and G92 reverts to its old behavior, as it is in Marlin 1.0.

#define MAX7219_INIT_TEST 2 // Test pattern at startup: 0=none, 1=sweep, 2=spiral #define MAX7219_NUMBER_UNITS 1 // Number of Max7219 units in chain. #define MAX7219_ROTATE 0 // Rotate the display clockwise (in multiples of +/- 90°) // connector at: right=0 bottom=-90 top=90 left=180

On a board with a ATmega2560/1280 micro-controller you have three potential serial ports to use for the MMU2: serial 1 (pins 18/19), serial 2 (pins 16/17), serial 3 (pins 14/15). Define the port your MMU2 is connected to - this activates an additional serial connection in Marlin named (in the example configuration) internalSerial.

The MMU2 LCD menu allows you to load filament to the nozzle. The MMU2 will transport the filament all the way to the extruder gears. The required extruder steps to load it into the hotend have to be defined in Marlin.

Replacing the LCD screen of your Creality Ender 3 with a touchscreen is a very simple upgrade. If you find yourself with a lot of free time while social distancing making sure your printer is running a peak efficiency is a nice constructive way to pass the time. Following these easy steps you can swap your Creality screen for a BigTreeTech TFT screen with minimal fuss. Your Ender 3 will be looking great in no time.

This upgrade is mostly cosmetic as the default screen on the Ender 3 isn’t much to look at. That is not to say that there isn’t added functionality with a new screen. The interface for options like the movement control are far easier to use on a touch screen. If you wanted to jog your nozzle 10mm to the right in X, -5 to the back in Y, and then 2 up in Z you would be jumping through multiple menus back and forth. With the touchscreen all those controls are displayed in one menu making it a lot easier.

The Bigtreetech TFT35-E3 v3.0 also has a full sized SD card slot, a USB slot, and connections for a filament runout sensor (if you have or want one) so there are some additional improvements to be had as well. The TFT35-E3 v3.0 also has a gcode terminal so you can run commands direct on the printer without the need of connecting it to a PC or Raspberry Pi. The TFT35-E3 v3.0 also has a spot to install a dedicated WiFi moduleif you want your printer hosted on your network.

The back of the stock Ender 3 LCD is connected to the printers mainboard by a single ribbon cable. Unplug this cable but try not to damage it. The cables that shipped with my TFT35-E3 were too short to reach from the screen to the board so I needed to reuse the original.

It does take a minute for the LCD to detect your printer and connect over serial so don’t worry if it says “No Printer Attached!” for a few seconds. If you long hold the dial/button you will be brought to a touch screen interface which allows you to select between the touch screen interface and the legacy Marlin interface. It is a nice option to have and if you are running with a stock Creality board then you will be using the legacy interface.

Compiling the firmware is not hard but Marlin 2.0 on a 32 bit board requires different software then was used previously. Atom was a popular editor but recently they have announced that it will not support Marlin going forward so our best choice is Microsoft Visual Studio Code. Download it and then install the PlatformIO extension.

The TFT-35 touch screen is a nice addition to my modified Ender 3. It allows for easier movement of the stepper motors from a single screen. I now have filament Load and Unload buttons which is an improvement to saying gcode files on the SD card and printing them to load filament.

I’ve just updated the Marlin firmware on my Sumpod 3d printer since I’m always keen to have the latest features and bug fixes. To be honest, I don’t mess with the firmware that much, and if it wasn’t for the configuration file from my last version, I would struggle to remember what sort of configuration I would need to set in the latest firmware version.

Anyway, while my latest experience with 3d printer firmware is still fresh in the mined, I’ll share some notes about what settings you need to know to get a basic Marlin firmware configured enough to get a 3d printer working. The notes will focus on the Marlin firmware v1 and will include setting up a click encoder and LCD panel. But before going straight into getting the Marlin firmware configured, I’ll first quickly introduce you to a handy tool called WinMerge.

While the latest Marlin firmware continues to be developed, with many new features being added all the time,  I’ve decided to maintain a snapshot of the firmware that this guide is based on. Using this guide with the firmware it is based on will give you the smoothest 3d printer set-up experience.

For anybody that’s in the business of editing and configuring 3d printer firmware files such as the Marlin firmware, I would suggest downloading a copy of WinMerge. It’s free, open source software, and is cross platform, so the same tool will run on Windows and Linux.

You can use WinMerge to compare a clean version of your Marlin firmware against your edited version that you are using on your 3d printer. This will help to keep track and note all the changes made to the files that you might want to transfer to a newer firmware version.

Some motherboards listed in the Marlin firmware configuration file may not have support for some of the options or features available to configure. The notes will be biased towards the Ramps 1.3 board, but the note will still be valid for any Marlin firmware compatible board.

This Marlin firmware will be useful to those who wish to configure their own 3d printer firmware and want information that expands on the comments already made in the Marlin firmware. The notes are a brief guide on what the settings are and how to use them, leaving it up to the person who is configuring the 3d printer to decide what the final settings should be. I don’t guarantee that the information in this Marlin firmware guide is accurate, however, if you spot any mistakes please leave a comment at the end of the post. The Marlin firmware guide is likely to be updated to improve the information where necessary after publishing.

For Marlin Firmware V1 you will need Arduino 0023 IDE to save, compile and upload to the 3d printer motherboard. In the following notes, to edit the firmware, I’ll be using line numbers to reference the location of the code in the Marlin firmware configuration file. Although there is no line numbering in the IDE editor window,  you will see the line number at the bottom left of the IDE showing the current cursor position. Just move the cursor to any line with the mouse to update the line number.

So, to get started, open up the Marlin firmware Configuration.h in the Arduino IDE and work down the notes below. Use WinMerge to compare the changes to a clean non-edited version of Configuration.h for final review before uploading to the 3d printer motherboard.

Line 20 marks the start of the Marlin firmware configuration journey and this is where the baud rate is set to determine the speed of the communication between the printer interface software and the Marlin firmware. Two common baud rate options are defined with one, preceded with two forward slashes (//), commented out to disable. The default enabled option, 250000 baud rate, works well when used with Printrun/Pronterface and RepSnapper software.

You will see a list of motherboards to choose from preceding the code snippet shown above in the Marlin firmware configuration file. The code snippet above defines the Ramps 1.3 as the motherboard, you can select a board just by changing the number to any board that’s on the list. The Marlin firmware will manage circuit board pin assignments to match the motherboard you have selected. Pin assignment details for each motherboard type can be found in the pins.h file of the Marlin firmware.

Now we come to the thermal settings section of the Marlin firmware where things get a bit more complicated, however, we don’t need to touch the complicated stuff to get the printer up and running. Basically all we need to do is select a temperature sensor type for each of the sensors installed on the 3d printer. If you did not install the temperature sensors yourself, you may have to investigate what sensors you do have so that you can select the best match from the list. More about thermistors on the RepRap wiki.

If you are looking at the Marlin firmware configuration file you will see a list of temperature sensor types preceding the code snippet shown above. The code snippet above is setting up the 3d printer that features one hot end and a heated build platform. The temperature sensor selected for both features is 100k thermistor.

If you are using the Ramps 1.3 motherboard with the default pin.h file in the Marlin firmware, the motherboard connectors T0 and T1 will be enabled for the hot end sensor and the heated bed sensor. Changing the 1 to a 0 will disable that sensor. Change the number to select the best match for your sensor from the list.

Some hot ends and heated build platforms might have a maximum temperature rating much less than the default settings in the Marlin firmware, reducing the default maximum temperatures will help avoid accidental damage to the 3d printer if set too high in the interface software.

The Marlin firmware Mechanical Settings section will be about configuring End Stops, Stepper Motors, Build Platform Printable area and Steps Per Unit.

This section will be about configuring end stops in the Marlin firmware that are the limit switches for each axis on the 3d printer. Issuing a homing command from the interface software will cause the 3d printer to mechanically move each axis towards the end stop until the limit switch is triggered.  ENDSTOPPULLUPS will need to be defined where you have limit switches that don’t supply a voltage to the signal pin to generate a digital 1. Enabling pull up resistors will ensure that the end stop signal line will read a digital 1, and when the signal line is shorted to ground by the limit switch, you get a digital 0.

In the Marlin firmware ENDSTOPPULLUPS is defined by default, and ENDSTOPPULLUPS for each end stop connector on the motherboard are enabled individually from line 207. However, commenting out line 194 will only disable ENDSTOPPULLUPS that are also commented out optionally for each connector from line 197. Having this kind of fine tuning makes it easier to configure different types of end stops connected to the 3d printer. You may have mechanical end stop switches for axis X and Y that need pull up resistors enabled and optical end stops that don’t need pull up resistors enabled.

If ENDSTOPPULLUPS at line 194 in the Configuration.h file of the Marlin firmware is commented out, then the code snippet above, starting at line 196, will execute. This code snippet will allow you to configure individual pull ups for each end stop connector on the motherboard. You would comment out a define statement for an end stop where you don’t need a pull up by preceding the line with two forward slashes. You would normally need to enable pull ups when using mechanical end stop type switches that just simply sink the signal pin to ground on the motherboard end stop connector.

You should test the homing command while the axis is positioned at the centre of the travel distance. If you find that the axis won’t move when the home command is sent, then you may have the logic incorrectly configured. Be ready to reset the motherboard or turn off the power to avoid axis crash. Before making any test, complete the Marlin firmware configuration as much as possible. If you can reach the end stops easily, you can trigger them early before the axis has completed it’s travel for a safe test.

The above code snippet found on line 219 of the Marlin firmware Configuration.h file is commented out by default, which allows homing axis to end stops where end stop switches are connected to the X+, Y+ and Z+ connectors on the motherboard.

Normally the above code snippet would not be changed in the Marlin firmware and all the settings would be set to false by default. However, if your 3d printer has a Z axis handle fitted like my 3d printer you might want to disable the Z axis so that the stepper motor can be turned by the Z axis handle while the 3d printer is printing. I’ve often made a Z height adjustment to fine tune the gap between the nozzle and the build bed as the first layer begins to print.

We have reached the part in the Marlin firmware configuration file where you configure stepper motor rotation direction, end stop direction, travel limits and steps per unit. As long as the end stops are configured correctly, the following settings should be easy enough to sort out during testing.

This is where we decide which direction each axis will go when we control the 3d printer through the interface software. When we send a command to move +10mm on an axis, we expect the axis to move 10mm in the direction expected. The initial stepper motor direction can be difficult to predict without switching on the printer and performing a test. So I would suggest leaving these settings till last and complete the rest of the Marlin firmware configuration before proceeding with the test.

Once the Marlin firmware Configuration file is configured enough to operate the 3d printer, you can perform a test to check that each axis move in the correct direction. Set each axis midpoint of their full travel distance and then switch on the printer. After connecting to the 3d printer through the interface software such as Printrun/pronterface, test each axis by jogging them 10mm in the positive direction. The stepper motor rotation direction for each axis can be corrected from line 233 in the Marlin firmware configuration by changing the logic.

You would need to test the extruder stepper motor direction as well. This can be done without filament loaded and bringing the hot end temperature up to 175 degrees so the Marlin firmware will allow extrusion. Send an extrude command through the 3d printer interface software and observe the direction the filament drive gear pulley rotation. The rotation direction for the extruder can be corrected from line 236 by changing the logic.

Basically you tell the Marlin firmware which end of the axis the end stop switch is located. It is common for X and Y axis to home the hot end to the Zero location and Z axis end stop home to the maximum positive location. The code snippet above and the image to the right shows that configuration.

The measurement units are in millimeters and are defined from line 249 for the maximum positions in the Marlin firmware configuration file. The minimum positions can be left at the default 0 for this configuration.

Configuring steps per unit will be one of the last bits of fine tuning you do before you start printing for the first time. Calculating steps per unit accurately will give the 3d printed parts the best start possible. However, if you are just upgrading the Marlin firmware or upgrading from any other firmware, you can get the steps per unit figures from the old configuration file if you still have it.

Steps per unit means the number of steps a stepper motor has to turn to equal 1mm of axis travel. The units at line 275 of the Marlin firmware configuration.h file are in the order of X, Y, Z and E. Getting the steps per unit from another printer of the same design would be very close to what you need, and will help you run some stepper motor tests before you get down to calculating accurate steps per unit for the Marlin firmware configuration file.

To calculate steps per unit (mm) to put in the Marlin firmware configuration file, you need to find a good way to measure axis travel distance accurately. You may have to temporary remove the hot end so that the filament can be extruded in order to make measurements. Using a dial indicator in place of the hot end and a ruler taped to the bed can provide a good accurate way to measured travelled distance. To get the best accuracy you should sample at least 100mm of axis travel. You command the printer to move the chosen axis 100mm using an interface software such as Pronterface. You then measure the actual distance the the axis travelled. Using the formula below you can calculate the new steps per unit.

At this point, you have done enough configuration in the Marlin firmware and can now start 3d printing. If you are interested in LCD display and click encoders, read on.

The last section in the Marlin firmware configuration file is for additional features, this section allows you to configure some of the optional extras you might have attached to your 3d printer. For the purpose of this guide I’m just going to include notes for the LCD 16×2 and the LCD 20×4 with click encoder control panel. The RAMPS 1.3 Arduino shield and my Marlin firmware configuration will be used for this guide.

Enabling an attached 16×2 LCD or click encoder control panel is straight forward in the Marlin firmware. However, the pin assignments for the attachment connectors need to match those in the Marlin firmware pins.h file. You can check if the LCD and click encoder panel features are supported for your motherboard by looking through the the pins.h file of the Marlin firmware. If you are just updating the Marlin firmware you can check for pin assignment changes by comparing your old pins.h configuration file with the new version of that file. Any changes found can be used to update the latest version of the Marlin firmware.

To enable any type of LCD support in the Marlin firmware, ULTRA_LCD needs to be defined. To add support for 16×2 LCD display, line 303 needs to be uncommented like the code snippet above, by removing the preceding forward slashes. By default, the Marlin firmware does not have LCD or click encoder control panel enabled. Enabling line 303 and nothing else will give you support for 16×2 LCD screen that is connected to the motherboard pins as assigned in the pins.h file. Pin assignments are found in the pins.h file of the Marlin firmware under each supported motherboard type.

There are two popular types of click encoder control panels that can be enabled for the RAMPS 1.3 board. The first type is the Ultipanel, which can be found on Thingiverse, and the other type is the RepRapDiscount Smart Controller. For this guide I’m just going add notes for the Ultipanel since the other type is supported by RepRapDiscount RepRap wiki for the Marlin firmware.

Both lines 307 and 331 are not enabled by default. To enable 20×4 LCD display and click encoder, uncomment both lines by removing the forward slashes. This would also enable SD Card support as well, a feature that will be covered in another guide. It will not be necessary to uncomment line 303 if line 307 is enabled by uncommenting. ULTRA_LCD will automatically be defined when ULTIPANEL is defined.

Well that concludes the Marlin firmware guide for now, and I would expect to be making updates going forward to correct errors if any are found or just to improve certain aspects of the guide.

If you have any questions or comments about the Marlin firmware guide, please leave them below. However, if you need Marlin firmware support, this is perhaps not the best place to get it.

Select the .bin file that matches your display-version and the display folder. For example, TFT35 V3.0 would select BIGTREE_TFT35_V3.0.25.1.bin and the TFT35 folder.

Note; the TFTxx folders have the fonts (.fon) & icons (.bmp) used; if you don"t copy this folder, you will not be able to read the prompts and the icons will be scrambled after the update. The reason is when flashing; the location to these files has changed, but the previous files don"t start at that new location.

Power up and wait, You will see some kind of updating status % if this doesn"t happen or fails; try another SD card. I think FAT32 works the best for these displays.

If you plan to use this SD card for printing Gcode files, then delete the .bin file; if not, then on each powerup or reset, the display will update as long as that file is in the root. No issues leaving the TFTxx folder since these files are only used when updating the firmware.

My TFT 24 from bigtreetech woun"t update, hangs in config.ini and stays in that screen. I tryed to flash with sw-link connection but that don"st work, also woun"t update.0

If you are having trouble flashing new firmware, ie the screen dpes not change after powering up, and you have a " printer not attached" error, the following shows settings to be followed, and is a good overview of the Marlin code issues that can arise.

Still missing 1 bmp file. U_DISK.bmp. I have checked all of the bmp files in all the directories and it is not there. The TFT will not update without it. Help!0

I have a BTT TFT35 v.2.0 and can´t find my screen in BTT github directory, only the v.3.0. But it also stands "support TFT35 V1.0/V1.1/V1.2/V2.0/V3.0, TFT28, TFT24 V1.1, TFT43, TFT50, TFT70" to the right of the codes. What should i do?0

Excellent instructions for updating the display. Thank you for taking the time to make this instructable. I Would not have figured it out on my own.ReplyUpvote

I was going to toss my BTT TFT 35 3.0 card because the screen was just like the one in your description. I followed your instructions and now my display works perfectly. thank you

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