Arduino Pico doesn't work with ST7735 screen I am attempting to get the graphicstest example bundled with the Adafruit ST7735 library for the 0.96 inch LCD screen.
The example runs fine and serial communication is up and running. However, nothing outputs on the screen. I verified that the code works with other Arduino boards and that I have it properly wired -&gt; SCK to SCL, MOSI to SDA, etc.
I'm not sure if I am doing something wrong, or if this is a limitation of the board.
Edit: I added the modified graphicstest code to the Internet, it can be found here: https://drive.google.com/file/d/1cFOgQXhhH1vou0KUrFzBDMp0iiIp1Yuy/view?usp=sharing
I also added a crude diagram of how the screen is wired up to the Pico. Note that the LCD is powered externally since the Pico cannot handle the current draw of powering the LCD.
https://drive.google.com/file/d/1RmZSHBcelwC9caLoQC9iE5Lb4eHG9S2O/view?usp=sharing
I found out the problem. I was trying to connect to the SCK and MOSI pins on the back of the Pico. Later research shows that these are meant for programming and burning a bootloader onto the microprocessor.
The Adafruit library allowed me to define my own pins for SCK and MOSI.
Once I switched to using the Adafruit_ST7735(int8_t cs, int8_t dc, int8_t mosi, int8_t sclk, int8_t rst) constructor, it worked after that.