The development of the custom hardware of an nRF52832 utilizing the u8g2 library has been shown to control a small display 64x48 SSD1306 driver. The prototype hardware another custom design with the nRF52832 fails to control the display. I believe the data control register signal/pin located at GPIO #6 is not responding. The firmware development is the same project located in the examples folder of the SDK15.3 library and being compiled with gcc from the command line inside PCA10040/blank/armgcc on a win 10 machine.
Their are several differences between the hardware that controls the display, namely, the bus select lines controlling the communication to the SSD1306 display and the prototype that does not. The one that works has both bus selects lines grounded and therefore a 4 line spi communication. On the prototype these lines are controlled from GPIO # 9 and #10. These require a program write to the register 0x1000120C with the value 0xFFFFFFFe written in order to control the two near field radio lines as GPIO. Both lines are pulled low through firmware and have been scoped.
The firmware works with another hardware, but the appropriate hardware with very nearly the same firmware only different board file for pin outs does not. I have three prototypes and all will not control the D/C line. If I change the working hardware and switch the D/C line over to pin 6 it also fails? Thank you for considering my dilemma!