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This will be a placeholder page where we will document technical aspects of our SPI master board.
- DEXA-C097 8-bit parallel epaper controller sold by Good Display (DEXA in further references)
- CINWRITE SPI HAT sold by us in Tindie. Ask as for older version if you need a better price.
- Any 9.7" epaper display sold by XSRUPB or other trusted seller in Aliexpress. Some compatible models that I tested are: ED097OC1, ED097OC4, ED097TC2 With different contrasts and VCOM settings.
In order that protocols I2C and SPI to work correctly a 0Hm resistance or bridge needs to be soldered where is indicated in this image. It's the number 6 count starting above the I2C connector, just at the left of the SPI connector in the line where the SO pin is:
If you compile the I2C scan example uncommenting it in CMakeLists:
# 1st test I2C scan: Find your I2C addresses
set(app_sources "tests/it8951-i2c-scan.cpp")
i2c scan:
Found device at: 0x49 -> IT8951 DEXA board
Found device at: 0x68 -> DS3231 RTC in this PCB
I2C works only in boards v1.1 or above. The pin routing had an error in first v1.0. Anyways if I2C is a problem and it does not work simple disconnect SDA & SCL and use SPI to communicate with DEXA board.
https://github.com/martinberlin/H-cinread-it8951/tree/main/Schematic
And please check our final product in the Tindie store so we can plan on making new versions when the first batch is gone.