LCD Display Driver

[Mathias]

Hello,

I bought a SainSmart display which fits on the PCA10028 development board. This display is a 16x2 character display with a HD44780 display contoller (I guess). Does anybody know if there is a driver available that runs on the nRF51422? If not, maybe I can adapt a driver for a similar display. Thanks, Mathias

[ovrebekk]

Hi Mathias

I made a simple bit-banged HD44780 driver for the nRF52 recently, but it uses only the GPIO and delay libraries and should work fine on the nRF51 as well.

The main limitation at the moment is that it assumes that all the control pins from the nRF5x will be together (ie pins P0.08-P0.15 without any unused pins in between), so you will have to make some changes to the library to get around this limitation.

nrf_hd44780.c
nrf_hd44780.h

Best regards
Torbjørn

[Mark]

I was afraid to damage my nRF52 board, so I managed to find another solution to work with HD44780. I'm using an IO Expander(PCF8574A) between the LCD and nRF52 board. Apparently the LCD has to be powered up with 5V input(3.3V didn't work for me), so I'm using two 2N7000 MOSFETs for voltage level shifting of TWI lines. I'm using the library provided in this link: hmario.home.xs4all.nl/.../

I managed to finally make it work, but I need to learn how to use "TWI events handler" for a more reliable coding practice, and I will create a new topic on how to do it.