mcauser
would it possible?
i have esp01 which have limited pins but i2c pins is there so i was thinking what if using PCF8574? it expand the GPIO pins and make PCD8544 to run behind PCF8574 woud it possible? i have been searching PCD8544 lib but mostly using SPI connection
The PCD8544 uses SPI to communicate. The minimum pins you'll need are CLK, DIN and D/C. CE and RST can be pulled low instead of using IOs.
The ESP-01 is very tight on pins. Any chance you can use one of the newer models with more pins broken out, eg ESP-12? Or an ESP32?
This guy had a crack at it. Not sure if it works. Looks like bit-banging SPI over the PCF8574 IO expander. https://github.com/maxint-rd/I2C-PCF8574-PCD8544-Nokia-5110-LCD
If you could bit-bang SPI over an IO expander, then sure, could be possible. I've never tried it. Refresh rate is going be be very slow compared to SPI. Like >20x slower. Otherwise, theres I2C to SPI bridge chips, such as SC18IS606. Again, it's going to be slow, but should be achievable.
