public GyroInterface() {
mSPI = new SPI(SPI.Port.kOnboardCS0);
mSPI.setClockRate(4_000_000);
mSPI.setChipSelectActiveLow();
mSPI.setClockActiveHigh();
mSPI.setSampleDataOnRising();
mSPI.setMSBFirst();
}
LEDTest() {
fred = new SPI(Port.kOnboardCS0);
fred.setClockRate(bitrate);
fred.setMSBFirst();
fred.setSampleDataOnFalling();
fred.setClockActiveLow();
fred.setChipSelectActiveLow();
}
public boolean write() {
byte[] cmd = new byte[17];
cmd[0] = cmd[1] = cmd[2] = cmd[3] = (byte) 0x00;
cmd[4] = cmd[5] = (byte) 0xF0;
cmd[6] = cmd[7] = (byte) 0x00;
cmd[8] = (byte) 0xFF;
cmd[9] = (byte) 0x00;
cmd[10] = (byte) 0x00;
cmd[11] = (byte) 0xFF;
cmd[12] = (byte) 0xFF;
cmd[13] = (byte) 0x00;
cmd[14] = (byte) 0xFF;
cmd[15] = (byte) 0x00;
cmd[16] = (byte) 0x00;
if (fred.write(cmd, cmd.length) != cmd.length) {
return false; // WRITE ERROR
}
return true;
}
/**
* @param command The word to write
* @return The result of the transaction
* @throws GyroInterface.GyroException if the transaction fails
*/
private int doTransaction(int command) throws GyroException {
// ensure the parity bit
if (!isOddParity(command & ~0x01)) {
command |= 0x01;
}
ByteBuffer resultBuffer = ByteBuffer.allocate(4);
int transactionSize =
mSPI.transaction(ByteBuffer.allocate(4).putInt(command).array(), resultBuffer.array(), 4);
if (transactionSize != 4) {
throw new GyroException("Transaction failed with size: " + transactionSize);
}
int result = resultBuffer.getInt(0);
// check the high-byte parity of the response
if (!isOddParity(result & 0xffff0000)) {
throw new GyroException("High bytes parity failure");
}
if (!isOddParity(result)) {
throw new GyroException("Whole word parity failure");
}
return result;
}
