Newhaven Products > Character LCDs

NHD-C0220Biz-FS(RGB)-FBW-3VM initialization problem


I'm using an embedded Linux system - with a dedicated I2C bus - to drive a "NHD-C0220Biz-FS(RGB)-FBW-3VM" display. The Linux kernel module supplies an I2C master, so I do not have to bit bang.
Using 'i2c_master_send(...)' does the addressing, clocking and so on. Most calls work but 0x39 and 0x01 don't work...
0x0  -> ok
0x38 -> ok
0x39 -> fail
0x14 -> ok
0x0c -> ok
0x01 -> fail

I also tried to make 2 byte packets {0x0, 0x?} and send them together but the same commands failed. And there is no visible reaction on the display.
Any sugestins?

Hmm, just found out that my dev board has 2.2k pull-up on SCL and SDA lines - instead of 10k as recommended. But my logic analyzer show all commands as expected...

Are you sending a delay between the commands or allowing the commands that were sent to execute?

Solved, the 2.2k poll-up was the root of the evil. Removed from the demo board and replaced by an external 10k, all is doing right!! Those 10k are pretty important...

Glad to hear you got your display up and running!

Thanks for sharing your solution, it will definitely help others  :D


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