Troubleshooting • RPi4b UART0 missing bytes from packet

Code:

PacketProcessor packetHandler;int PacketProcessor::run(){  //Processing Incoming if present, otherwise transmit  if(0 < serDataAvailable(h))  {    printf("Got serial data!\n");    //wait 1 ms for packet to be received    gpioDelay(1000);    int t_bytesToRead = serDataAvailable(h);    printf("There are %d bytes to read.\n", t_bytesToRead);    for(int i = 0; i < t_bytesToRead; i++)    {      inputBuffer[i] = serReadByte(h);      printf("Data: %X\n", inputBuffer[i]);    }          printf("Validity Check start\n");           //Check packet validity    int t_packetLength = inputBuffer[PACKET_LENGTH_INDEX];    bool t_packetLengthValid = (t_packetLength == t_bytesToRead);    int t_startOfPacket = 0;    int t_endOfPacket   = t_packetLength - 1;    bool t_recoveryCompleted = false;    //Possibly a bad packet    if(!t_packetLengthValid)    {        //attempt to search for start delimiter        for(int i = 1; i < t_endOfPacket && (!t_recoveryCompleted); i++)        {            if(inputBuffer[i] == PACKET_START_DELIMITER)            {                // Serial.print("  Start delimiter found at index: ");                // Serial.println(i);                // Log.info("  Start delimiter found at index: %d", i);                if(inputBuffer[ i + PACKET_LENGTH_INDEX ] + i == t_bytesToRead)                {                    // Serial.println("  Length Match! Shifting packet");                    // Log.info("  Length Match! Shifting packet");                    for(int j = 0; j < i; j++) {                        char *temp = logBuffer;                        temp += sprintf(temp, "%X - ", inputBuffer[j]);                    }                    // Log.info("  Bytes Removed: %s", logBuffer);                    //shift it all over                    int packetLength = inputBuffer[ i + PACKET_LENGTH_INDEX ];                    for(int j = 0; j < packetLength ; j++)                    {                        // Log.info("Copying: %X from index: %d to index: %d", inputBuffer[j + i], j+i, j);                        inputBuffer[j] = inputBuffer[j + i];                    }                    //Update parameters                    t_packetLength = inputBuffer[PACKET_LENGTH_INDEX];                    t_endOfPacket = t_packetLength - 1;                    t_packetLengthValid = true;                    // Serial.println("  Recovery complete");                    // Log.info("  Recovery complete");                    t_recoveryCompleted = true;                    // break;                }            }        }    }    //if bytes read matches length    if(t_packetLengthValid)    {        if( (PACKET_START_DELIMITER == inputBuffer[0]) &&            (PACKET_END_DELIMITER == inputBuffer[t_endOfPacket]))        {            int t_CRC = (inputBuffer[t_endOfPacket - 2] << 8) | inputBuffer[t_endOfPacket - 1];            int t_CRCCalced = calculateCRC(inputBuffer,  t_packetLength -3);            // Serial.print("CRC in packet: ");            // Serial.println(t_CRC,HEX);            // Serial.print("CRC calced: ");            // Serial.println(t_CRCCalced,HEX);            // Log.info("CRC in packet: %X", t_CRC);            // Log.info("CRC calced: %X", t_CRCCalced);            if(t_CRC == t_CRCCalced)            {                // Serial.println("CRC Match!");                // Log.info("CRC Match!");                inputPacketPayloadLength = t_packetLength - 3 - PACKET_PAYLOAD_START_INDEX; // Isolate Payload Length                // Serial.print("Payload Length: ");                // Serial.println(inputPacketPayloadLength);                // Serial.println("\r\n");                // Log.info("Payload Length: %d", inputPacketPayloadLength);                inputPendingPacket = 1;            }        }    } else {        for(int j = 0; j < t_bytesToRead; j++) {            char *temp = logBuffer;            temp += sprintf(temp, "%X - ", inputBuffer[j]);            // Log.info("  Byte Skipped: %X", )        }        printf("  Invalid Packet: %s\n", logBuffer);    }    unsigned long readTime = micros()-testTime;    // Log.info("PacketProcessor.run.read time: %lu", readTime);  }  else  {    if(0 != outputPendingPacket)    {      printf("Sending serial data!\n");      printf("Packet Contents: %X %X %X %X %X %X %X %X %X %X\n\n", outputBuffer[0], outputBuffer[1], outputBuffer[2], outputBuffer[3], outputBuffer[4], outputBuffer[5], outputBuffer[6], outputBuffer[7], outputBuffer[8], outputBuffer[9]);      // Log.info("Sending serial data!");                  //Serial1.write(outputBuffer, outputPacketLength);            //set TXE pin high      gpioWrite(UART_TEMP_TE_PIN, 1);      gpioSleep(PI_TIME_RELATIVE, 0, 100);            //send packet      serWrite(h, outputBuffer, outputPacketLength);      outputPendingPacket = 0;      gpioSleep(PI_TIME_RELATIVE, 0, 1040);            //set TXE pin low      gpioWrite(UART_TEMP_TE_PIN, 0);      gpioSleep(PI_TIME_RELATIVE, 0, 100);    }  }    return 0;}void processSerial(){    static unsigned long timeOfLastUpdate = 0;    unsigned long currentTime = millis();    if(125 <= ((currentTime - timeOfLastUpdate) & 0xFFFFFFFFFFFFFFFF))    {        //printf("processSerial timer triggered\n");        timeOfLastUpdate = currentTime;        packetHandler.run();    }}int main(void){if (gpioInitialise() < 0){printf("PiGPIO library initialization failed.\n");return 0;}//set Pi pinmodesassignGpioMode();packetHandler.begin();while(1){processSerial();}return 0;}

Code:

Serial port initialized!Sending serial data!Packet Contents: F5 7 10 20 5 49 FE 0 0 0Got serial data!There are 15 bytes to read.Data: C6Data: EAData: 60Data: 0Data: C6Data: EAData: 60Data: 0Data: C6Data: EAData: 60Data: 0Data: 55Data: 22Data: FEValidity Check start  Invalid Packet: FE -