M-SoM A5 behavior to SD card chip select

Firmware
1

Hello friends,

I'm trying to use one board developed to B-SoM with M-SoM.
But I have problems with the SD card
It uses pin 43 (A5) as chip select.
A5 has a different behavior in M-SoM, with 40K pull-down at boot, could this be the cause?
I also saw that the other pins used have differences in Internal pull resistance, But I don't think this can get in the way:
Pin 50 (MISO) / Pin 52 (MOSI) / Pin 54 (SCK)
B-SoM: 13K
M-SoM: 2.1K

Any possible configuration tips for using the A5 as a select chip for the SD Card?
And about the frequency at SD.begin()?
Thanks!

#include <Particle.h>
#include "SdFat.h"
SerialLogHandler logHandler;
int8_t SCS = A5; // chip select
SdFat SD;
SdFile file;
bool sdok;

void setup() {
sdok = SD.begin(SCS, SD_SCK_HZ(4 * MHZ));
 if (sdok)
    {
        Log.info("sd card ok!");
    }
    else
    {
        Log.info("sd card error!!");
    }
}
void loop() { //// }
2

Hi, and welcome to the community!

What deviceOS version are you using? If you are using 5.8.0, please try 5.8.2.
There was a SPI bug present in the 5.8.0 version.
Cheers

1 Like
3

I updated via the CLI and the problem was resolved, thank you very much. However, I was unable to update the firmware using the Web IDE as version 5.8.2 does not appear available for M-SoM devices.

4

Device OS 5.8.2 was added to the Web IDE yesterday. You may need to refresh to get it to display.

1 Like
5

Despite being implemented in version 5.8.0 (for M-SoM), in version 5.8.2 i can not choose which interface to connect to.

Error: Could not compile.
"no matching function for call to 'CloudClass::connect(spark::CellularClass&)"

6

Particle.connect() with a network type, such as Particle.connect(WiFi) was available in 5.6.0 to 5.8.1, but was removed from 5.8.2 and later because using it can lead to unpredictable behavior with automatic connection management.

7

It proved useful with M-SoM, but ok!
Thank you for the clarification

8

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