Uncanny Eyes for ESP8266 without Chip Select

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robkopf
 
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Uncanny Eyes for ESP8266 without Chip Select

Post by robkopf »

Long time listener...first time caller!

I have a couple of 1.3" 240x240 SPI ST7789 screens and a bunch of ESP8266 NodeMCUs lying around and thought I could implement the Uncanny Eyes code for Halloween. Last year I used the Arduino Eyes Bonnet on a RPi in a 3D printed jack-o-lantern that turned out great.

These screens do not have a Chip Select pin (CS is actually tied to GND internally). I have the NodeMCU connected to the screens and running test software I found on Simple-Circuits - https://simple-circuit.com/esp8266-node ... s-display/

Has anyone used these screens with the Uncanny Eyes project?

Thanks!

Rob

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adafruit_support_mike
 
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Re: Uncanny Eyes for ESP8266 without Chip Select

Post by adafruit_support_mike »

You can work around the CS problem by running the signals through a logic buffer like the 74x125:

https://www.adafruit.com/product/1787

It has active-low ENABLE pins on each signal, and those do exactly the same thing as an SPI CS pin. For devices that think they always own the SPI bus, it's a good idea to buffer all three signals: COPI/MOSI and SCK from the microcontroller to the device, and CIPO/MISO from the device to the microcontroller.

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