A look at an ESP32 based bitcoin module

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In this article we take a look at an ESP32 based cryptocurrency ticker, this consists of an ESP32 with an LCD connected to it, the data is transferred by an online crypto api and displayed on the LCD. I am a fan of crypto and have built examples simialr with individual parts so an all in one module was appealing

I bought the following module but had a few issues, the module had code installed but it was the incorrect wifi credentials based on the default in the code in the github archive – this means you will have to modify the code and reprogram the module – this is not that tricky.

The 3 buttons did not appear to have any function in the bitcoin example and the sd card is also not used in the example code but if you know what you are doing you can add this functionality

The archive is at – https://github.com/LilyGO/ESP32-TTGO-T4

Images

Here are some images of the module

 

Code

You need the Arduino IDE and add support for esp32 – http://www.esp32learning.com/tutorials/adding-support-for-esp32-boards.php

You need to install the following libraries – these can be installed via the library manager

https://github.com/bblanchon/ArduinoJson

https://github.com/adafruit/Adafruit-GFX-Library

https://github.com/adafruit/Adafruit_ILI9341

https://github.com/PaulStoffregen/Time

I used version 5.3.12 of the ArduinoJson library as the latest gave a ‘DynamicJsonBuffer’ was not declared in this scope when I tried to compile the example

Also the default instructions in the github miss the Time library which leads to a compilation error

You need to change the wifi credentials in the code otherwise you will not be able to retrieve the latest prices – look for the following lines and modify them

const char* ssid = “TP-LINK_888”;
const char* password = “Zhang520521”;

Here is a backup of the code this is in case the archive goes offline – ESP32-TTGO-T4-master

 

Link

The module comes in at about $20 which is reasonable value for an ESP32 module with built in IL9341 LCD

TTGO New BTC Ticker ESP32 for Arduino 4 MB SPI Flash 4 MB PsramSource Bitcoin Price Ticker Program