SOLVED : SD fat on Software SPI not compiling on MightyCore 1284p about sdfat

[greiman]

I don't have a 8 MHz MightyCore so I can't help you.

I no longer test SdFat with 1284P boards.

[SrikanthBala]

Thank you sir for your prompt response. I am designing a new device which requires more pins than a ATMega 328. Hence I chose the 1284P. The other option I have is a Maple Mini like STM32 board. It is fast, has the pins I need and is cost effective.
However I tried SdFat today on SPI1 using a LC MicroSd Shield bypassing the 5V regulator and using direct 3.3 V. However the level converter IC is not bypassed (its datasheet mentions it will work correctly for all voltages above 2.6v)

However the STM32 card returns failure to find the card using the SdInfo.ino. Pin connections made for SP1 and checked multiple times. No sketch works for SD card indicating a basic fault in my system. Does your SdFat support STM32 Core ?

[greiman]

Arduino STM32 requires the old Arduino IDE 1.6.12.

SdFat no longer works reliably on STM32 and I don't want to fix it for 1.6.12.

[SrikanthBala]

Ok

[stevstrong]

A short comment:
Arduino_STM32 code works with both SdFat and SdFat beta, with Arduino 1.6.9 or later.
But: it only works with SD card modules designed for 3.3V, without 5V->3.3V regulator, see:
http://www.stm32duino.com/viewtopic.php?f=13&t=20, section "Known problems".

[SrikanthBala]

Thank you stevstrong.
I closed this issue earlier thinking I should just give up on the 1284p and the Mighty Core for Software SPI. I just got back here to see your comment. I AM using a 3.3V modified microSD module (as my 1284p is also running at 3.3V). I'll definitely give it a go with my Black Pill STM32 board.

Meanwhile I reopened this because I finally found the problem with my code for the 1284P.

First to solve the compiling problem. I needed to modify the GpioPinMap.h file. The original GpioPinMap.h file in the SDfat library under "SdFat/SdFat/src/SdSpiCard/boards/GpioPinMap.h" has the following two lines which need to be changed to compile under the MCUDUDE MightyCore :

Near the end of the file :
#elif defined(ARDUINO_1284P_BOBUINO)
needs to be changed to #elif defined(BOBUINO_PINOUT)
and
#elif defined(ARDUINO_1284P_STANDARD)
needs to be changed to #elif defined(STANDARD_PINOUT)

After this the code compiled and uploaded but no luck. SD card could not be read.

After nearly 24 hrs of breaking my head on multiple SD card adapters and finally fixing one 'impossible to see' internally broken jumper wire, and trying a zillion other combinations, I found in a 2012 Arduino forum that SdFat SoftwareSpi assumes a Standard or Sanguino pinout and not Bobuino pinout. So I switched to Standard pinout names in the code and BINGO ! it worked !
In fact it does not matter whether I select Bobuino board or Standard board under the boards selection for the Mighty Core. It still works on the Standard Pin names only as if the Standard Pins were somehow hardcoded into the SDFat SoftwareSPI code ignoring the definitions in Gpio.h. I dont currently know how to modify SDFat to use the right pins so I'll leave it at that, as I know how to get the the code to work.

Thanks Greiman for the library once again. And incidentally I tried it at both 16MHz and 8Mhz too and it works GREAT !
I hope this helps someone else struggling on similar lines. Bye