The Right Size

Published on 2017-08-30 in Trinket M0 TFT.

Adafruit just recently released a new version of their Trinket boards, this time with the Atmel SAMD21 Cortex-M0 ARM chip, and with CircuitPython loaded on it by default. Of course I had to get a couple, and managed to do it before they went out of stock.

By a complete coincidence, the package with them arrived as the same time as the package from Aliexpress with the tiny ST7735 TFT display screens. I put them one next to the other, and what do you know — a perfect fit!

So I fired up my trusty Fritzing and quickly made a breakout board for this display, with the pins matching the pins on the Trinket M0. A few clicks later I have the order placed for OSHPark.

(Yeah, I was in a hurry, so one of the mounting holes is slightly shifted. Oh well.)

Because I only had five pins to use, and I’m not entirely sure if I can use the MISO pin for other purpose while the SPI is used on this microcontroller, I had to hard-wire the LED and CS pins. By a complete coincidence, the SCL pin is free (it’s the MISO pin), and the SDA pin is the same as DC — so I think I should be still able to use the I²C bus with this connected.