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("----------------------------------------------------------");

[HeroDesign]

I'm using 2.1.0

---

PI4J PROVIDERS

PROVIDERS: [12] "I/O Providers" <com.pi4j.provider.impl.DefaultProviders>
├─SPI: [2] <com.pi4j.io.spi.SpiProvider>
│ ├─PROVIDER: "PiGpio SPI Provider" {pigpio-spi} <com.pi4j.plugin.pigpio.provider.spi.PiGpioSpiProviderImpl> {com.pi4j.plugin.pigpio.provider.spi.PiGpioSpiProviderImpl}
│ └─PROVIDER: "RaspberryPi SPI Provider" {raspberrypi-spi} <com.pi4j.plugin.raspberrypi.provider.spi.RpiSpiProviderImpl> {com.pi4j.plugin.raspberrypi.provider.spi.RpiSpiProviderImpl}
├─DIGITAL_INPUT: [2] <com.pi4j.io.gpio.digital.DigitalInputProvider>
│ ├─PROVIDER: "RaspberryPi Digital Input (GPIO) Provider" {raspberrypi-digital-input} <com.pi4j.plugin.raspberrypi.provider.gpio.digital.RpiDigitalInputProviderImpl> {com.pi4j.plugin.raspberrypi.provider.gpio.digital.RpiDigitalInputProviderImpl}
│ └─PROVIDER: "PiGpio Digital Input (GPIO) Provider" {pigpio-digital-input} <com.pi4j.plugin.pigpio.provider.gpio.digital.PiGpioDigitalInputProviderImpl> {com.pi4j.plugin.pigpio.provider.gpio.digital.PiGpioDigitalInputProviderImpl}
├─DIGITAL_OUTPUT: [2] <com.pi4j.io.gpio.digital.DigitalOutputProvider>
│ ├─PROVIDER: "PiGpio Digital Output (GPIO) Provider" {pigpio-digital-output} <com.pi4j.plugin.pigpio.provider.gpio.digital.PiGpioDigitalOutputProviderImpl> {com.pi4j.plugin.pigpio.provider.gpio.digital.PiGpioDigitalOutputProviderImpl}
│ └─PROVIDER: "RaspberryPi Digital Output (GPIO) Provider" {raspberrypi-digital-output} <com.pi4j.plugin.raspberrypi.provider.gpio.digital.RpiDigitalOutputProviderImpl> {com.pi4j.plugin.raspberrypi.provider.gpio.digital.RpiDigitalOutputProviderImpl}
├─ANALOG_INPUT: [0] <com.pi4j.io.gpio.analog.AnalogInputProvider>
├─ANALOG_OUTPUT: [0] <com.pi4j.io.gpio.analog.AnalogOutputProvider>
├─I2C: [2] <com.pi4j.io.i2c.I2CProvider>
│ ├─PROVIDER: "PiGpio I2C Provider" {pigpio-i2c} <com.pi4j.plugin.pigpio.provider.i2c.PiGpioI2CProviderImpl> {com.pi4j.plugin.pigpio.provider.i2c.PiGpioI2CProviderImpl}
│ └─PROVIDER: "RaspberryPi I2C Provider" {raspberrypi-i2c} <com.pi4j.plugin.raspberrypi.provider.i2c.RpiI2CProviderImpl> {com.pi4j.plugin.raspberrypi.provider.i2c.RpiI2CProviderImpl}
├─PWM: [2] <com.pi4j.io.pwm.PwmProvider>
│ ├─PROVIDER: "PiGpio PWM Provider" {pigpio-pwm} <com.pi4j.plugin.pigpio.provider.pwm.PiGpioPwmProviderImpl> {com.pi4j.plugin.pigpio.provider.pwm.PiGpioPwmProviderImpl}
│ └─PROVIDER: "RaspberryPi PWM Provider" {raspberrypi-pwm} <com.pi4j.plugin.raspberrypi.provider.pwm.RpiPwmProviderImpl> {com.pi4j.plugin.raspberrypi.provider.pwm.RpiPwmProviderImpl}
└─SERIAL: [2] <com.pi4j.io.serial.SerialProvider>
├─PROVIDER: "PiGpio Serial Provider" {pigpio-serial} <com.pi4j.plugin.pigpio.provider.serial.PiGpioSerialProviderImpl> {com.pi4j.plugin.pigpio.provider.serial.PiGpioSerialProviderImpl}
└─PROVIDER: "RaspberryPi Serial Provider" {raspberrypi-serial} <com.pi4j.plugin.raspberrypi.provider.serial.RpiSerialProviderImpl> {com.pi4j.plugin.raspberrypi.provider.serial.RpiSerialProviderImpl}

[taartspi]

As you are using and older build there can be multiple providers loaded. You can see there are two spi providers. Not certain which will be used in your code. Add the line to explicitly load the pigpio

.provider("pigpio-spi")
.build();

Later. Builds automatically enforce a single provider for each IO type. If that experiment doesn't resolve your problem i will set up your environment and try it to see what is going on

[HeroDesign]

Thank you.
Yes. Adding the provider specifically like that did solve this issue. I can now see data coming back.
However, when I run this on our hardware the returning data is unstable, sometimes returning all 0s.
When I run our older code using an older version of pi4j on the exact same hardware the return data is highly stable.
Can you provide any insight into what might have changed about SPI communication in this version of pi4j that might be different?

[taartspi]

As you would have copied the mode and baud rate from the V1 code that works, I can't think of any expected difference you might see. But I think I would try a lower baud rate to see if it performs differently. And may a read operation immediately after the transfer to see if your device did not have sufficient time to return the real data.

[FDelporte]

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