Unable to send or receive SPI data after upgrade to 2.0

[HeroDesign]

I have a system that uses SPI for communication between a raspberry pi 3b+ and custom hardware.

The system was built using and older version of pi4j (1.0 I think, circa 2013). I have recently needed to update the firmware on our build for the pi and was forced up upgrade to pi4j 2.0.

Since that update I have not been able to successfully send and receive SPI data using pi4j.

I have removed our custom hardware from the system and looped MOSI and MISO and tested with python successfully to ensure SPI is working at a low level.

However, I'm unable to get pi4j to work.

Here are the relevant section of code:

Configure SPI, all settings taken from our previous working build:

   pi4j = Pi4J.newAutoContext();
    SpiConfig spiConfig = Spi.newConfigBuilder(pi4j)
            .id("SPI0")
            .name("SPI Communication")
            .address(0)  // Use SPI channel 0
            .mode(3)
            .baud(30000000)  // 30 MHz
            .build();
    spi = pi4j.create(spiConfig);

Attempted RW, here I am using spi.transfer, in the old version I used Spi.wiringPiSPIDataRW(0, message, 8200); :

while (true) {
    byte[] message = new byte[8200];
    byte[] readMessage = new byte[8200];
    spiTimer.stop();
        if (sendFrameQueue.peek() != null) {
            message = (byte[]) sendFrameQueue.peek();
            System.out.println("Attempting to send data over SPI: " + getHexString(message));
            int success = spi.transfer(message, readMessage);
            System.out.println("success ="+success );
            System.out.println("Attempting to get  data over SPI: " + getHexString(readMessage));
            byte[] returnMessage = parseSpiRetunrn_v1(readMessage);
            System.out.println("Parsed SPI return message: " + getHexString(returnMessage));
            recvFrameQueue.offer(returnMessage);
            sendFrameQueue.poll();
        } else {
        }
    spiTimer.reset();
    spiTimer.start();
    try {
        Thread.sleep(hatSpeed);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

success is always 0 and the readMessage is always empty.
Thanks in advance for any help!

[taartspi]

the release 2.0 is the first for v2. 2.8.0 is the most recent. In moving to it best to read each release note to understand changes.
Then after you create the context add this code and paste the results. tom

var console = new Console();
System.out.println("----------------------------------------------------------");
System.out.println("PI4J PROVIDERS");
System.out.println("----------------------------------------------------------");
pi4j.providers().describe().print(System.out);
System.out.println("----------------------------------------------------------");

[FDelporte]

Other idea: could there be a thread issue? Receiving the data and handling it maybe should be handled separately?

[HeroDesign]

The problem seems to be some difference in the way pigpio manages spi from wiringpi.

I tried to downgrade to to the version of pi4j I was using (1.1) and tried to get that to work with the current version of wiringpi.
I was able to get that version of wiringpi to work on its own but not with the older version of pi4j.
I tried to find the same version of wiringpi that I was using 2.4.6 but could not file a branch that built without error.

Is there anyway to use pi4j 2.1 with the current version of wiringpi?

[taartspi]

I do not believe any wiringpi is compatible with V2

I never investigated if pigpio has any buffer size constraints. If you send much fewer bytes does the that invalidate your chips operation or will it return some valid data. Or have another spi device with simpler operating steps you can test

[HeroDesign]

Is there a linuxfs-spi provider?

[taartspi]

https://www.pi4j.com/documentation/providers/linuxfs/.
Yes there is a linuxfs spi provider.
I know you began this research sometime ago. Do you have a means to monitor spi master slave lines and the CS