Is there anything special about the pins on EXT?

[tfcroft4]

I have bought 3 16x24 lED display boards from AdaFruit. "16x24 Red LED Matrix Panel - Chainable HT1632C Driver "
http://www.adafruit.com/products/555

AdaFruit supply a HT1632 library for these boards. http://ladyada.net/products/16x24LEDmatrix/

I tried interfacing to the boards from the EXT connector using these defines.

Code Select Expand

#define WR   32 // Olimex on EXT 10 WR is CLOCK when writing ; yellow
#define DATA 34 // Olimex on EXT 12 ; blue
#define CS0  35 // Olimex on EXT 13 ; white
#define CS1  36 // Olimex on EXT 14
#define CS2  37 // Olimex on EXT 15

Using these pins I could not get any output on the display. ( I am pretty sure I had connected them correctly!)

However using the following pins on CON 4 Digital does give me output.

Code Select Expand

#define WR   9   // Olimex WR is CLOCK when writing YELLOW
#define DATA 10    // Olimex BLUE
#define CS1  11     // Olimex WHITE 1
#define CS2  12 // Olimex WHITE 2
#define CS3  14 // Olimex WHITE 3

Is there anything special about the pins on the EXT connector?

Thanks

[LubOlimex]

Hello there,

If you notice the schematic here: https://www.olimex.com/Products/Duino/STM32/OLIMEXINO-STM32/resources/OLIMEXINO-STM32_Rev_D.pdf, there is multiplexing between the UEXT and the SD card. Check the signals in parenthesis.

You will have to disconnect the SD card when trying to use those multiplexed signals.

Note that you can use SPI1 (MISO1, MOSI1, etc) on CON4 which is not multiplexed anywhere.

Best regards,
Lub/OLIMEX