esp32-cam tft display made in china

2023-01-03 12:32:11

This ESP32-CAM Project covers how to use ESP32-CAM with a TFT display to show the picture captured by the cam. We have covered several times how to use ESP32-CAM in different projects and we have described how to use ESP32-CAM in Machine Learning projects. Even if we can use ESP32-CAM with a Web server to show pictures, in this post we want to cover how to show a picture on a TFT screen (ST7735). Therefore, we would like to visualize the picture taken by the ESP32-CAM directly on the display. In this case, we use an ST7735s display, anyway, you can select a different TFT if you like.

You should already know how to take a picture using an ESP32-CAM therefore we will focus on two aspects only:How to connect the ESP32-CAM to TFT display

This is the most interesting part because here we will show the picture taken by the ESP32-CAM on the TFT display. To do it, we will use the TJpg_Decoder library because it simplifies our work. First of all, we use a low-resolution such as 120×160 so that the picture fits in the TFT.

defining the scale and the callback method used to render the picture:bool tft_output(int16_t x, int16_t y, uint16_t w, uint16_t h, uint16_t* bitmap){

At the end of this tutorial, you have learned how to use ESP32-CAM with TFT display. In this project we have integrated ESP32-CAM with ST7735 to show the image captured. We have build a simple camera machine using ESP32-CAM.

esp32-cam tft display made in china

At first it was not successful, since most examples useTJpg_Decoderand it use a lot of memory, causing the ESP32-CAM crash then reboot. Then I found out that there"s an function from the ESP32 library to convert JPEG into RGB565 (which is the format used by the Adafruit driver). I can even scale the image to 1/2 side size (= 1/4) so it fit the ST7735S 160x128 or 128x128 displays nicely. Everything works and problem solved.

You can find some more details about wiring, the training data (Kaggle Cats and Dogs Dataset) and the model (MobileNetV1 96x96 0.25 with transfer learning) on my repo. There"s also a copy of my model library and a boilerplate version (without using button and TFT).

The train accuracy is 89.8% and test accuracy is 86.97% on Edge Impulse. Captured image is 240x240 (resized to 120x120 on TFT and 96x96 for the model). Model inference (predict) time on ESP32-CAM is 2607 ms (2.6 secs). It"s not fast, but the setup is so cheap I think this can actually be useful as real world applications...?

esp32-cam tft display made in china

We have used Liquid Crystal Displays in the DroneBot Workshop many times before, but the one we are working with today has a bit of a twist – it’s a circle! Perfect for creating electronic gauges and special effects.

LCD, or Liquid Crystal Displays, are great choices for many applications. They aren’t that power-hungry, they are available in monochrome or full-color models, and they are available in all shapes and sizes.

Today we will see how to use this display with both an Arduino and an ESP32. We will also use a pair of them to make some rather spooky animated eyeballs!

There are also some additional connections to the display. One of them, DC, sets the display into either Data or Command mode. Another, BL, is a control for the display’s backlight.

The above illustration shows the connections to the display. The Waveshare display can be used with either 3.3 or 5-volt logic, the power supply voltage should match the logic level (although you CAN use a 5-volt supply with 3.3-volt logic).

Another difference is simply with the labeling on the display. There are two pins, one labeled SDA and the other labeled SCL. At a glance, you would assume that this is an I2C device, but it isn’t, it’s SPI just like the Waveshare device.

This display can be used for the experiments we will be doing with the ESP32, as that is a 3.3-volt logic microcontroller. You would need to use a voltage level converter if you wanted to use one of these with an Arduino Uno.

The Waveshare device comes with a cable for use with the display. Unfortunately, it only has female ends, which would be excellent for a Raspberry Pi (which is also supported) but not too handy for an Arduino Uno. I used short breadboard jumper wires to convert the ends into male ones suitable for the Arduino.

Once you have everything hooked up, you can start coding for the display. There are a few ways to do this, one of them is to grab the sample code thatWaveshare provides on their Wiki.

The Waveshare Wiki does provide some information about the display and a bit of sample code for a few common controllers. It’s a reasonable support page, unfortunately, it is the only support that Waveshare provides(I would have liked to see more examples and a tutorial, but I guess I’m spoiled by Adafruit and Sparkfun LOL).

Open the Arduino folder. Inside you’ll find quite a few folders, one for each display size that Waveshare supports. As I’m using the 1.28-inch model, I selected theLCD_1inch28folder.

You can see from the code that after loading some libraries we initialize the display, set its backlight level (you can use PWM on the BL pin to set the level), and paint a new image. We then proceed to draw lines and strings onto the display.

After uploading the code, you will see the display show a fake “clock”. It’s a static display, but it does illustrate how you can use this with the Waveshare code.

This library is an extension of the Adafruit GFX library, which itself is one of the most popular display libraries around. Because of this, there isextensive documentation for this libraryavailable from Adafruit. This makes the library an excellent choice for those who want to write their own applications.

As with the Waveshare sample, this file just prints shapes and text to the display. It is quite an easy sketch to understand, especially with the Adafruit documentation.

The sketch finishes by printing some bizarre text on the display. The text is an excerpt from The Hitchhiker’s Guide to the Galaxy by Douglas Adams, and it’s a sample of Vogon poetry, which is considered to be the third-worst in the Galaxy!

Here is the hookup for the ESP32 and the GC9A01 display. As with most ESP32 hookup diagrams, it is important to use the correct GPIO numbers instead of physical pins. The diagram shows the WROVER, so if you are using a different module you’ll need to consult its documentation to ensure that you hook it up properly.

The TFT_eSPI library is ideal for this, and several other, displays. You can install it through your Arduino IDE Library Manager, just search for “TFT_eSPI”.

There is a lot of demo code included with the library. Some of it is intended for other display sizes, but there are a few that you can use with your circular display.

To test out the display, you can use theColour_Test sketch, found inside the Test and Diagnostic menu item inside the library samples. While this sketch was not made for this display, it is a good way to confirm that you have everything hooked up and configured properly.

A great demo code sample is theAnimated_dialsketch, which is found inside theSpritesmenu item. This demonstration code will produce a “dial” indicator on the display, along with some simulated “data” (really just a random number generator).

One of my favorite sketches is the Animated Eyes sketch, which displays a pair of very convincing eyeballs that move. Although it will work on a single display, it is more effective if you use two.

The first thing we need to do is to hook up a second display. To do this, you connect every wire in parallel with the first display, except for the CS (chip select) line.

The Animated Eyes sketch can be found within the sample files for the TFT_eSPI library, under the “generic” folder. Assuming that you have wired up the second GC9A01 display, you’ll want to use theAnimated_Eyes_2sketch.

The GC9A01 LCD module is a 1.28-inch round display that is useful for instrumentation and other similar projects. Today we will learn how to use this display with an Arduino Uno and an ESP32.

esp32-cam tft display made in china