XPlorer 16/32 Dev Board - SPI for TFT Color Display

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XPlorer 16/32 Dev Board - SPI for TFT Color Display

Postby GGRUK » Mon Sep 12, 2022 10:03 am

I found this old thread about XPlorer16 Dev Board and an issue with SPI. Although, this thread is about the conflict between USB & SPI, I think this is the only thread I found to post my difficulties with XPlorer16/32 Board with SPI.

I am using PIC24FJ256GB410 PIM and trying to communicate with a TFT color display 80x160 using SPI. I have the code provided by the manufacturer of the display EA Germany. I am using the MIKR BUS A to connect SPI pins to the display. It did work for some hours. But when I disconnected the 9V dc Power supply and connected it again, it stopped working. Since then it does not work.
I am able to see all the signals on the pins of Mikro Bus A (SCK, MOSI, CS and other pins like VCC, GND, RS(D/C selection for the display), Display RESET pin and also the SDA pin on the display. I see these on Logic Pro. All values seem to be correct. When I wrote a simple loop to send repeated commands to the display, Logic Pro shows them correctly as sent. But nothing happens on the display.

Is there an issue of conflict or 'cross-over' of RX & DX pins, as stated on SPI1?
Could this be the reason why nothing is actually sent to the display?

I am using the following pins on Mikro BUS A for SPI connection to the display.
I have configured SPI as spi3 on the PIC PIM
Pin 1 of J20: ANP25: RS(D/C choice on display in a 4 wire interface)
Pin 2 of J20: P95: RESET for display
Pin 3 of J20: P14: CSA
Pin 4 of J20: P10: SCKA
Pin 5 of J20: P11: MISO this is connected directly to SDA of display (although I don't read the display)
Pin 6 of J20: P12: MOSI connected to SDA through 100R
Pin 7 of J20: 3.3V connected to VCC of display
Pin 8 of J20: GND connected to GND of display.
The LED backlight A & K are connected between 3.3V & GND through a potentiometer where I can vary the current.
Currently backlight is ON and I can vary the brightness with LED current from 5mA to 20mA - currently set at 10mA
The 4W pin on the display is connected to 3.3V to put SPI into 4 wire mode.
I have tried first with Winstar 0.96" display (80x16) where the code ran and I could see the colour display in demo mode for several hours. Since it has stopped working after OFF-ON of the 9V power supply, I have tries two other makes of the displays of similar types. But nothing is seen.

I am going to try to use the pins on Mikro Bus B if this can solve the problem.

Or is it better that I don't use the pins meant for USB and connect to tother pins if available for SPI on the main ?

Thanks in advance. Please ask if you need any more details.


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Joined: Mon Sep 12, 2022 9:39 am

Re: XPlorer 16/32 Dev Board - SPI for TFT Color Display

Postby GGRUK » Mon Sep 12, 2022 10:04 am

Hi ric

Follwoing your suggestion, I have posted my issue here.
Please help and also guide how to ensure that the XPlorer board is working.

Posts: 2
Joined: Mon Sep 12, 2022 9:39 am

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