SPI Transfer error

Endpoint
1

I try to communicate with an MP3 Click module connected on Click #1 (but same thing for Click #2) on an endpoint.
Here is code:

using GHIElectronics.Endpoint.Core;
using static GHIElectronics.Endpoint.Core.EPM815;
using System.Device.Spi;
using System.Device.Gpio;
using System.Device.Gpio.Drivers;
using System.Numerics;

namespace testVs1053b
{
    internal class Program
    {
        static private byte[] cmdBuffer = new byte[4];
        static private byte[] readBuffer = new byte[4];

        static void Main(string[] args)
        {
            Console.WriteLine("Hello, World!");

            // Construct SPI bus cmdSetting
            EPM815.Spi.Initialize(EPM815.Spi.Spi4);
            var setting = new SpiConnectionSettings(EPM815.Spi.Spi4)
            {
                ClockFrequency = 2_000_000,
 //               Mode = SpiMode.Mode0,
                //ChipSelectLineActiveState = false,
                //DataFlow=DataFlow.MsbFirst,
                //DataBitLength=8,
                //BusId=EPM815.Spi.Spi4
            };
            var _spi = SpiDevice.Create(setting);

            // Construct pins
            // CS pin
            var pinNumberCS = EPM815.Gpio.Pin.PZ7;

            var portCS = pinNumberCS / 16;
            var pinCS = pinNumberCS % 16;
            var gpioDriverCS = new LibGpiodDriver(portCS);
            var gpioCS = new GpioController(PinNumberingScheme.Logical, gpioDriverCS);
            if (gpioCS == null) throw new NullReferenceException("GpioCS is null");
            gpioCS.OpenPin(pinCS);
            gpioCS.SetPinMode(pinCS, PinMode.Output);
            gpioCS.Write(pinCS, PinValue.High);

            // DCS pin
            var pinNumberDCS = EPM815.Gpio.Pin.PZ6;

            var portDCS = pinNumberDCS / 16;
            var pinDCS = pinNumberDCS % 16;
            var gpioDriverDCS = new LibGpiodDriver(portDCS);
            var gpioDCS = new GpioController(PinNumberingScheme.Logical, gpioDriverDCS);
            if (gpioDCS == null) throw new NullReferenceException("GpioDCS is null");
            gpioDCS.OpenPin(pinDCS);
            gpioDCS.SetPinMode(pinDCS, PinMode.Output);
            gpioDCS.Write(pinDCS, PinValue.High);

            // Reset pin
            var pinNumberReset = EPM815.Gpio.Pin.PA12;

            var portReset = pinNumberReset / 16;
            var pinReset = pinNumberReset % 16;
            var gpioDriverReset = new LibGpiodDriver(portReset);
            var gpioReset = new GpioController(PinNumberingScheme.Logical, gpioDriverReset);
            if (gpioReset == null) throw new NullReferenceException("GpioReset is null");
            gpioReset.OpenPin(pinReset);
            gpioReset.SetPinMode(pinReset, PinMode.Output);
            gpioReset.Write(pinReset, PinValue.High);

            // Dreq pin
            var pinNumberDreq = EPM815.Gpio.Pin.PC3;

            var portDreq = pinNumberDreq / 16;
            var pinDreq = pinNumberDreq % 16;
            var gpioDriverDreq = new LibGpiodDriver(portDreq);
            var gpioDreq = new GpioController(PinNumberingScheme.Logical, gpioDriverDreq);
            if (gpioDreq == null) throw new NullReferenceException("GpioDreq is null");
            gpioDreq.OpenPin(pinDreq);
            gpioDreq.SetPinMode(pinDreq, PinMode.InputPullUp);

            // Reset Module
            gpioReset.Write(pinReset, PinValue.Low);
            Thread.Sleep(1);
            gpioReset.Write(pinReset, PinValue.High);
            Thread.Sleep(1);

            // Get Status 
            cmdBuffer[0] = 0x03;
            cmdBuffer[1] = 0x01; // Get SCI_STATUS
            cmdBuffer[2] = 0;
            cmdBuffer[3] = 0;

            gpioCS.Write(pinCS, PinValue.Low);
            _spi.TransferFullDuplex(cmdBuffer, readBuffer);
            gpioCS.Write(pinCS, PinValue.High);


        }
    }
}

It throws an exception when I try transfer via SPI:

image
image1111Ă—145 18.9 KB

I’ve try to set mode (or not, it seems to be Mode0 by default), but I always obtain this error.

2

Add the line “GHI add” to your code. We will mention this is our doc if that fix the problem.

var setting = new SpiConnectionSettings(EPM815.Spi.Spi4)
{
    ClockFrequency = 2_000_000,

    ChipSelectLine = 0 // GHI added
};
1 Like
3

You are the error killer ! That is fixed !

3 Likes
4

Can someone please explain why we have System.Device.Spi as well as EPM815.Spi namespaces?

5

I think first one is implementation of communication (read, write, transfer …) whereas the second, is which pin on endpoint (link to STM32) is connected (MISO, MOSI, …).

6

System.Device.Spi from Microsoft.

EPM815.Spi from GHI as advanced, that allows you change pins or buffer size (next release).

7

So I figured I’ll add to this convo instead of starting a new one. I’m having similar troubles transferring data over SPI. “System.IO.IOException: Error 22 performing SPI data transfer.”
Mode = 3, Clock Frequency = 100000

image
image1324Ă—748 124 KB

EDIT: It was the clock frequency. Seems it needs to be 1Mhz? Weird.

8

This is the function that throws:

It’s pretty disappointing that all you see is “error 22” not some specific explanatory text. Here’s the control code it’s sending to the driver:

9

I will confess to not having tried your code snippet @Mr_John_Smith , but errno 22 (EINVAL) means that the underlying code didn’t like one of the provided arguments. Some combination of the values provided (or omitted) in _spiConnectionSettings is giving the underlying linux driver some indigestion. Are the expected values being pulled out of config into your locals?

10

Yes. the SpiMode = 3, and Clock Frequency = 100Khz. It didn’t like 100Khz, and I had to increase it to 1Mhz.

1 Like