Subversion Repositories FlightCtrl

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Copyright (c) 04.2007 Holger Buss
// + Nur für den privaten Gebrauch
// + www.MikroKopter.com
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Es gilt für das gesamte Projekt (Hardware, Software, Binärfiles, Sourcecode und Dokumentation),
// + dass eine Nutzung (auch auszugsweise) nur für den privaten und nicht-kommerziellen Gebrauch zulässig ist.
// + Sollten direkte oder indirekte kommerzielle Absichten verfolgt werden, ist mit uns (info@mikrokopter.de) Kontakt
// + bzgl. der Nutzungsbedingungen aufzunehmen.
// + Eine kommerzielle Nutzung ist z.B.Verkauf von MikroKoptern, Bestückung und Verkauf von Platinen oder Bausätzen,
// + Verkauf von Luftbildaufnahmen, usw.
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Werden Teile des Quellcodes (mit oder ohne Modifikation) weiterverwendet oder veröffentlicht,
// + unterliegen sie auch diesen Nutzungsbedingungen und diese Nutzungsbedingungen incl. Copyright müssen dann beiliegen
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Sollte die Software (auch auszugesweise) oder sonstige Informationen des MikroKopter-Projekts
// + auf anderen Webseiten oder Medien veröffentlicht werden, muss unsere Webseite "http://www.mikrokopter.de"
// + eindeutig als Ursprung verlinkt und genannt werden
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Keine Gewähr auf Fehlerfreiheit, Vollständigkeit oder Funktion
// + Benutzung auf eigene Gefahr
// + Wir übernehmen keinerlei Haftung für direkte oder indirekte Personen- oder Sachschäden
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Die Portierung der Software (oder Teile davon) auf andere Systeme (ausser der Hardware von www.mikrokopter.de) ist nur
// + mit unserer Zustimmung zulässig
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Die Funktion printf_P() unterliegt ihrer eigenen Lizenz und ist hiervon nicht betroffen
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Redistributions of source code (with or without modifications) must retain the above copyright notice,
// + this list of conditions and the following disclaimer.
// +   * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived
// +     from this software without specific prior written permission.
// +   * The use of this project (hardware, software, binary files, sources and documentation) is only permittet
// +     for non-commercial use (directly or indirectly)
// +     Commercial use (for example: selling of MikroKopters, selling of PCBs, assembly, ...) is only permitted
// +     with our written permission
// +   * If sources or documentations are redistributet on other webpages, out webpage (http://www.MikroKopter.de) must be
// +     clearly linked as origin
// +   * porting to systems other than hardware from www.mikrokopter.de is not allowed
// +  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// +  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// +  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// +  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// +  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// +  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// +  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// +  POSSIBILITY OF SUCH DAMAGE.
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include <avr/pgmspace.h>
#include <stdarg.h>
#include <string.h>

#include "eeprom.h"
#include "menu.h"
#include "timer0.h"
#include "uart0.h"
#include "rc.h"
#include "externalControl.h"
#include "output.h"
#include "attitude.h"


#ifdef USE_MK3MAG
#include "mk3mag.h"
#endif

#define FC_ADDRESS 1
#define NC_ADDRESS 2
#define MK3MAG_ADDRESS 3

#define FALSE   0
#define TRUE    1
//int8_t test __attribute__ ((section (".noinit")));
uint8_t request_VerInfo = FALSE;
uint8_t request_ExternalControl = FALSE;
uint8_t request_Display = FALSE;
uint8_t request_Display1 = FALSE;
uint8_t request_DebugData = FALSE;
uint8_t request_Data3D = FALSE;
uint8_t request_DebugLabel = 255;
uint8_t request_PPMChannels = FALSE;
uint8_t request_MotorTest = FALSE;
uint8_t request_variables = FALSE;

uint8_t DisplayLine = 0;

volatile uint8_t txd_buffer[TXD_BUFFER_LEN];
volatile uint8_t rxd_buffer_locked = FALSE;
volatile uint8_t rxd_buffer[RXD_BUFFER_LEN];
volatile uint8_t txd_complete = TRUE;
volatile uint8_t ReceivedBytes = 0;
volatile uint8_t *pRxData = 0;
volatile uint8_t RxDataLen = 0;

uint8_t motorTestActive = 0;
uint8_t motorTest[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
uint8_t ConfirmFrame;

typedef struct {
        int16_t Heading;
}__attribute__((packed)) Heading_t;

DebugOut_t DebugOut;
Data3D_t Data3D;
UART_VersionInfo_t UART_VersionInfo;

uint16_t DebugData_Timer;
uint16_t Data3D_Timer;
uint16_t DebugData_Interval = 500; // in 1ms
uint16_t Data3D_Interval = 0; // in 1ms

#ifdef USE_MK3MAG
int16_t Compass_Timer;
#endif

// keep lables in flash to save 512 bytes of sram space
const prog_uint8_t ANALOG_LABEL[32][16] = {
                //1234567890123456
                "AnglePitch      ", //0
                "AngleRoll       ",
                "AngleYaw        ",
                "GyroPitch(PID)  ",
                "GyroRoll(PID)   ",
                "GyroYaw         ", //5
                "GYRO_RATE_FACTOR",
                "GYRO_RATE_FACTOR",
                "unused          ",
                "AccPitch (angle)",
                "AccRoll (angle) ", //10
                "UBat            ",
                "Pitch Term      ",
                "Roll Term       ",
                "Yaw Term        ",
                "Throttle Term   ", //15
                "0th O Corr pitch",
                "0th O Corr roll ",
                "unused          ",
        "unused          ",
                "dHeightThrottle ", //20
                "hoverThrottle   ",
                "M1              ",
                "M2              ",
                "M3              ",
                "M4              ", //25
                "ControlYaw      ",
                "Airpress. Range ",
                "DriftCompPitch  ",
                "DriftCompRoll   ",
                "AirpressFiltered", //30
                "AirpressADC     " };

/****************************************************************/
/*              Initialization of the USART0                    */
/****************************************************************/
void usart0_Init(void) {
        uint8_t sreg = SREG;
        uint16_t ubrr = (uint16_t) ((uint32_t) SYSCLK / (8 * USART0_BAUD) - 1);

        // disable all interrupts before configuration
        cli();

        // disable RX-Interrupt
        UCSR0B &= ~(1 << RXCIE0);
        // disable TX-Interrupt
        UCSR0B &= ~(1 << TXCIE0);

        // set direction of RXD0 and TXD0 pins
        // set RXD0 (PD0) as an input pin
        PORTD |= (1 << PORTD0);
        DDRD &= ~(1 << DDD0);
        // set TXD0 (PD1) as an output pin
        PORTD |= (1 << PORTD1);
        DDRD |= (1 << DDD1);

        // USART0 Baud Rate Register
        // set clock divider
        UBRR0H = (uint8_t) (ubrr >> 8);
        UBRR0L = (uint8_t) ubrr;

        // USART0 Control and Status Register A, B, C

        // enable double speed operation in
        UCSR0A |= (1 << U2X0);
        // enable receiver and transmitter in
        UCSR0B = (1 << TXEN0) | (1 << RXEN0);
        // set asynchronous mode
        UCSR0C &= ~(1 << UMSEL01);
        UCSR0C &= ~(1 << UMSEL00);
        // no parity
        UCSR0C &= ~(1 << UPM01);
        UCSR0C &= ~(1 << UPM00);
        // 1 stop bit
        UCSR0C &= ~(1 << USBS0);
        // 8-bit
        UCSR0B &= ~(1 << UCSZ02);
        UCSR0C |= (1 << UCSZ01);
        UCSR0C |= (1 << UCSZ00);

        // flush receive buffer
        while (UCSR0A & (1 << RXC0))
                UDR0;

        // enable interrupts at the end
        // enable RX-Interrupt
        UCSR0B |= (1 << RXCIE0);
        // enable TX-Interrupt
        UCSR0B |= (1 << TXCIE0);

        // initialize the debug timer
        DebugData_Timer = SetDelay(DebugData_Interval);

        // unlock rxd_buffer
        rxd_buffer_locked = FALSE;
        pRxData = 0;
        RxDataLen = 0;

        // no bytes to send
        txd_complete = TRUE;

#ifdef USE_MK3MAG
        Compass_Timer = SetDelay(220);
#endif

        UART_VersionInfo.SWMajor = VERSION_MAJOR;
        UART_VersionInfo.SWMinor = VERSION_MINOR;
        UART_VersionInfo.SWPatch = VERSION_PATCH;
        UART_VersionInfo.ProtoMajor = VERSION_SERIAL_MAJOR;
        UART_VersionInfo.ProtoMinor = VERSION_SERIAL_MINOR;

        // restore global interrupt flags
        SREG = sreg;
}

/****************************************************************/
/* USART0 transmitter ISR                                       */
/****************************************************************/
ISR(USART0_TX_vect)
{
        static uint16_t ptr_txd_buffer = 0;
        uint8_t tmp_tx;
        if (!txd_complete) { // transmission not completed
                ptr_txd_buffer++; // die [0] wurde schon gesendet
                tmp_tx = txd_buffer[ptr_txd_buffer];
                // if terminating character or end of txd buffer was reached
                if ((tmp_tx == '\r') || (ptr_txd_buffer == TXD_BUFFER_LEN)) {
                        ptr_txd_buffer = 0; // reset txd pointer
                        txd_complete = 1; // stop transmission
                }
                UDR0 = tmp_tx; // send current byte will trigger this ISR again
        }
        // transmission completed
        else
                ptr_txd_buffer = 0;
}

/****************************************************************/
/* USART0 receiver               ISR                            */
/****************************************************************/
ISR(USART0_RX_vect)
{
        static uint16_t crc;
        static uint8_t ptr_rxd_buffer = 0;
        uint8_t crc1, crc2;
        uint8_t c;

        c = UDR0; // catch the received byte

        if (rxd_buffer_locked)
                return; // if rxd buffer is locked immediately return

        // the rxd buffer is unlocked
        if ((ptr_rxd_buffer == 0) && (c == '#')) { // if rxd buffer is empty and syncronisation character is received
                rxd_buffer[ptr_rxd_buffer++] = c; // copy 1st byte to buffer
                crc = c; // init crc
        }
#if 0
        else if (ptr_rxd_buffer == 1) { // handle address
                rxd_buffer[ptr_rxd_buffer++] = c; // copy byte to rxd buffer
                crc += c; // update crc
        }
#endif
        else if (ptr_rxd_buffer < RXD_BUFFER_LEN) { // collect incomming bytes
                if (c != '\r') { // no termination character
                        rxd_buffer[ptr_rxd_buffer++] = c; // copy byte to rxd buffer
                        crc += c; // update crc
                } else { // termination character was received
                        // the last 2 bytes are no subject for checksum calculation
                        // they are the checksum itself
                        crc -= rxd_buffer[ptr_rxd_buffer - 2];
                        crc -= rxd_buffer[ptr_rxd_buffer - 1];
                        // calculate checksum from transmitted data
                        crc %= 4096;
                        crc1 = '=' + crc / 64;
                        crc2 = '=' + crc % 64;
                        // compare checksum to transmitted checksum bytes
                        if ((crc1 == rxd_buffer[ptr_rxd_buffer - 2]) && (crc2
                                        == rxd_buffer[ptr_rxd_buffer - 1])) {
                                // checksum valid
                                rxd_buffer[ptr_rxd_buffer] = '\r'; // set termination character
                                ReceivedBytes = ptr_rxd_buffer + 1;// store number of received bytes
                                rxd_buffer_locked = TRUE; // lock the rxd buffer
                                // if 2nd byte is an 'R' enable watchdog that will result in an reset
                                if (rxd_buffer[2] == 'R') {
                                        wdt_enable(WDTO_250MS);
                                } // Reset-Commando
                        } else { // checksum invalid
                                rxd_buffer_locked = FALSE; // unlock rxd buffer
                        }
                        ptr_rxd_buffer = 0; // reset rxd buffer pointer
                }
        } else { // rxd buffer overrun
                ptr_rxd_buffer = 0; // reset rxd buffer
                rxd_buffer_locked = FALSE; // unlock rxd buffer
        }
}

// --------------------------------------------------------------------------
void AddCRC(uint16_t datalen) {
        uint16_t tmpCRC = 0, i;
        for (i = 0; i < datalen; i++) {
                tmpCRC += txd_buffer[i];
        }
        tmpCRC %= 4096;
        txd_buffer[i++] = '=' + tmpCRC / 64;
        txd_buffer[i++] = '=' + tmpCRC % 64;
        txd_buffer[i++] = '\r';
        txd_complete = FALSE;
        UDR0 = txd_buffer[0]; // initiates the transmittion (continued in the TXD ISR)
}

// --------------------------------------------------------------------------
// application example:
// SendOutData('A', FC_ADDRESS, 2, (uint8_t *)&request_DebugLabel, sizeof(request_DebugLabel), label, 16);
/*
 void SendOutData(uint8_t cmd, uint8_t addr, uint8_t numofbuffers, ...) { // uint8_t *pdata, uint8_t len, ...
 va_list ap;
 uint16_t txd_bufferIndex = 0;
 uint8_t *currentBuffer;
 uint8_t currentBufferIndex;
 uint16_t lengthOfCurrentBuffer;
 uint8_t shift = 0;

 txd_buffer[txd_bufferIndex++] = '#';                   // Start character
 txd_buffer[txd_bufferIndex++] = 'a' + addr;            // Address (a=0; b=1,...)
 txd_buffer[txd_bufferIndex++] = cmd;                   // Command

 va_start(ap, numofbuffers);

 while(numofbuffers) {
 currentBuffer = va_arg(ap, uint8_t*);
 lengthOfCurrentBuffer = va_arg(ap, int);
 currentBufferIndex = 0;
 // Encode data: 3 bytes of data are encoded into 4 bytes,
 // where the 2 most significant bits are both 0.
 while(currentBufferIndex != lengthOfCurrentBuffer) {
 if (!shift) txd_buffer[txd_bufferIndex] = 0;
 txd_buffer[txd_bufferIndex]  |= currentBuffer[currentBufferIndex] >> (shift + 2);
 txd_buffer[++txd_bufferIndex] = (currentBuffer[currentBufferIndex] << (4 - shift)) & 0b00111111;
 shift += 2;
 if (shift == 6) { shift=0; txd_bufferIndex++; }
 currentBufferIndex++;
 }
 }
 // If the number of data bytes was not divisible by 3, stuff
 //  with 0 pseudodata  until length is again divisible by 3.
 if (shift == 2) {
 // We need to stuff with zero bytes at the end.
 txd_buffer[txd_bufferIndex]  &= 0b00110000;
 txd_buffer[++txd_bufferIndex] = 0;
 shift = 4;
 }
 if (shift == 4) {
 // We need to stuff with zero bytes at the end.
 txd_buffer[txd_bufferIndex++] &= 0b00111100;
 txd_buffer[txd_bufferIndex]    = 0;
 }
 va_end(ap);
 AddCRC(pt); // add checksum after data block and initates the transmission
 }
 */

void SendOutData(uint8_t cmd, uint8_t addr, uint8_t numofbuffers, ...) { // uint8_t *pdata, uint8_t len, ...
        va_list ap;
        uint16_t pt = 0;
        uint8_t a, b, c;
        uint8_t ptr = 0;

        uint8_t *pdata = 0;
        int len = 0;

        txd_buffer[pt++] = '#'; // Start character
        txd_buffer[pt++] = 'a' + addr; // Address (a=0; b=1,...)
        txd_buffer[pt++] = cmd; // Command

        va_start(ap, numofbuffers);

        if (numofbuffers) {
                pdata = va_arg(ap, uint8_t*);
                len = va_arg(ap, int);
                ptr = 0;
                numofbuffers--;
        }

        while (len) {
                if (len) {
                        a = pdata[ptr++];
                        len--;
                        if ((!len) && numofbuffers) {
                                pdata = va_arg(ap, uint8_t*);
                                len = va_arg(ap, int);
                                ptr = 0;
                                numofbuffers--;
                        }
                } else
                        a = 0;
                if (len) {
                        b = pdata[ptr++];
                        len--;
                        if ((!len) && numofbuffers) {
                                pdata = va_arg(ap, uint8_t*);
                                len = va_arg(ap, int);
                                ptr = 0;
                                numofbuffers--;
                        }
                } else
                        b = 0;
                if (len) {
                        c = pdata[ptr++];
                        len--;
                        if ((!len) && numofbuffers) {
                                pdata = va_arg(ap, uint8_t*);
                                len = va_arg(ap, int);
                                ptr = 0;
                                numofbuffers--;
                        }
                } else
                        c = 0;
                txd_buffer[pt++] = '=' + (a >> 2);
                txd_buffer[pt++] = '=' + (((a & 0x03) << 4) | ((b & 0xf0) >> 4));
                txd_buffer[pt++] = '=' + (((b & 0x0f) << 2) | ((c & 0xc0) >> 6));
                txd_buffer[pt++] = '=' + (c & 0x3f);
        }
        va_end(ap);
        AddCRC(pt); // add checksum after data block and initates the transmission
}

// --------------------------------------------------------------------------
void Decode64(void) {
        uint8_t a, b, c, d;
        uint8_t x, y, z;
        uint8_t ptrIn = 3;
        uint8_t ptrOut = 3;
        uint8_t len = ReceivedBytes - 6;

        while (len) {
                a = rxd_buffer[ptrIn++] - '=';
                b = rxd_buffer[ptrIn++] - '=';
                c = rxd_buffer[ptrIn++] - '=';
                d = rxd_buffer[ptrIn++] - '=';
                //if(ptrIn > ReceivedBytes - 3) break;

                x = (a << 2) | (b >> 4);
                y = ((b & 0x0f) << 4) | (c >> 2);
                z = ((c & 0x03) << 6) | d;

                if (len--)
                        rxd_buffer[ptrOut++] = x;
                else
                        break;
                if (len--)
                        rxd_buffer[ptrOut++] = y;
                else
                        break;
                if (len--)
                        rxd_buffer[ptrOut++] = z;
                else
                        break;
        }
        pRxData = &rxd_buffer[3];
        RxDataLen = ptrOut - 3;
}

// --------------------------------------------------------------------------
void usart0_ProcessRxData(void) {
        // We control the motorTestActive var from here: Count it down.
        if (motorTestActive)
                motorTestActive--;
        // if data in the rxd buffer are not locked immediately return
        if (!rxd_buffer_locked)
                return;
        uint8_t tempchar1, tempchar2;
        Decode64(); // decode data block in rxd_buffer

        switch (rxd_buffer[1] - 'a') {

        case FC_ADDRESS:
                switch (rxd_buffer[2]) {
#ifdef USE_MK3MAG
                case 'K':// compass value
                compassHeading = ((Heading_t *)pRxData)->Heading;
                // compassOffCourse = ((540 + compassHeading - compassCourse) % 360) - 180;
                break;
#endif
                case 't': // motor test
                        if (RxDataLen > 20) {
                                memcpy(&motorTest[0], (uint8_t*) pRxData, sizeof(motorTest));
                        } else {
                                memcpy(&motorTest[0], (uint8_t*) pRxData, 4);
                        }
                        motorTestActive = 255;
                        externalControlActive = 255;
                        break;

                case 'n':// "Get Mixer Table
                        while (!txd_complete)
                                ; // wait for previous frame to be sent
                        SendOutData('N', FC_ADDRESS, 1, (uint8_t *) &Mixer, sizeof(Mixer));
                        break;

                case 'm':// "Set Mixer Table
                        if (pRxData[0] == EEMIXER_REVISION) {
                                memcpy(&Mixer, (uint8_t*) pRxData, sizeof(Mixer));
                                MixerTable_WriteToEEProm();
                                while (!txd_complete)
                                        ; // wait for previous frame to be sent
                                tempchar1 = 1;
                        } else {
                                tempchar1 = 0;
                        }
                        SendOutData('M', FC_ADDRESS, 1, &tempchar1, 1);
                        break;

                case 'p': // get PPM channels
                        request_PPMChannels = TRUE;
                        break;

                case 'q':// request settings
                        if (pRxData[0] == 0xFF) {
                                pRxData[0] = GetParamByte(PID_ACTIVE_SET);
                        }
                        // limit settings range
                        if (pRxData[0] < 1)
                                pRxData[0] = 1; // limit to 1
                        else if (pRxData[0] > 5)
                                pRxData[0] = 5; // limit to 5
                        // load requested parameter set
                        ParamSet_ReadFromEEProm(pRxData[0]);
                        tempchar1 = pRxData[0];
                        tempchar2 = EEPARAM_REVISION;
                        while (!txd_complete)
                                ; // wait for previous frame to be sent
                        SendOutData('Q', FC_ADDRESS, 3, &tempchar1, sizeof(tempchar1),
                                        &tempchar2, sizeof(tempchar2), (uint8_t *) &staticParams,
                                        sizeof(staticParams));
                        break;

                case 's': // save settings
                        if (!(MKFlags & MKFLAG_MOTOR_RUN)) // save settings only if motors are off
                        {
                                if ((1 <= pRxData[0]) && (pRxData[0] <= 5) && (pRxData[1]
                                                == EEPARAM_REVISION)) // check for setting to be in range and version of settings
                                {
                                        memcpy(&staticParams, (uint8_t*) &pRxData[2], sizeof(staticParams));
                                        ParamSet_WriteToEEProm(pRxData[0]);
                                        tempchar1 = getActiveParamSet();
                                        beepNumber(tempchar1);
                                } else {
                                        tempchar1 = 0; //indicate bad data
                                }
                                while (!txd_complete)
                                        ; // wait for previous frame to be sent
                                SendOutData('S', FC_ADDRESS, 1, &tempchar1, sizeof(tempchar1));
                        }
                        break;

                default:
                        //unsupported command received
                        break;
                } // case FC_ADDRESS:

        default: // any Slave Address
                switch (rxd_buffer[2]) {
                case 'a':// request for labels of the analog debug outputs
                        request_DebugLabel = pRxData[0];
                        if (request_DebugLabel > 31)
                                request_DebugLabel = 31;
                        externalControlActive = 255;
                        break;

                case 'b': // submit extern control
                        memcpy(&externalControl, (uint8_t*) pRxData, sizeof(externalControl));
                        ConfirmFrame = externalControl.frame;
                        externalControlActive = 255;
                        break;

                case 'h':// request for display columns
                        externalControlActive = 255;
                        RemoteKeys |= pRxData[0];
                        if (RemoteKeys)
                                DisplayLine = 0;
                        request_Display = TRUE;
                        break;

                case 'l':// request for display columns
                        externalControlActive = 255;
                        MenuItem = pRxData[0];
                        request_Display1 = TRUE;
                        break;

                case 'v': // request for version and board release
                        request_VerInfo = TRUE;
                        break;

                case 'x':
                        request_variables = TRUE;
                        break;

                case 'g':// get external control data
                        request_ExternalControl = TRUE;
                        break;

                case 'd': // request for the debug data
                        DebugData_Interval = (uint16_t) pRxData[0] * 10;
                        if (DebugData_Interval > 0)
                                request_DebugData = TRUE;
                        break;

                case 'c': // request for the 3D data
                        Data3D_Interval = (uint16_t) pRxData[0] * 10;
                        if (Data3D_Interval > 0)
                                request_Data3D = TRUE;
                        break;

                default:
                        //unsupported command received
                        break;
                }
                break; // default:
        }
        // unlock the rxd buffer after processing
        pRxData = 0;
        RxDataLen = 0;
        rxd_buffer_locked = FALSE;
}

/************************************************************************/
/* Routine für die Serielle Ausgabe                                     */
/************************************************************************/
int16_t uart_putchar(int8_t c) {
        if (c == '\n')
                uart_putchar('\r');
        // wait until previous character was send
        loop_until_bit_is_set(UCSR0A, UDRE0);
        // send character
        UDR0 = c;
        return (0);
}

//---------------------------------------------------------------------------------------------
void usart0_TransmitTxData(void) {
        if (!txd_complete)
                return;

        if (request_VerInfo && txd_complete) {
                SendOutData('V', FC_ADDRESS, 1, (uint8_t *) &UART_VersionInfo,
                                sizeof(UART_VersionInfo));
                request_VerInfo = FALSE;
        }

        if (request_Display && txd_complete) {
                LCD_PrintMenu();
                SendOutData('H', FC_ADDRESS, 2, &DisplayLine, sizeof(DisplayLine),
                                &DisplayBuff[DisplayLine * 20], 20);
                DisplayLine++;
                if (DisplayLine >= 4)
                        DisplayLine = 0;
                request_Display = FALSE;
        }

        if (request_Display1 && txd_complete) {
                LCD_PrintMenu();
                SendOutData('L', FC_ADDRESS, 3, &MenuItem, sizeof(MenuItem), &MaxMenuItem,
                                sizeof(MaxMenuItem), DisplayBuff, sizeof(DisplayBuff));
                request_Display1 = FALSE;
        }

        if (request_DebugLabel != 0xFF) { // Texte für die Analogdaten
                uint8_t label[16]; // local sram buffer
                memcpy_P(label, ANALOG_LABEL[request_DebugLabel], 16); // read lable from flash to sram buffer
                SendOutData('A', FC_ADDRESS, 2, (uint8_t *) &request_DebugLabel,
                                sizeof(request_DebugLabel), label, 16);
                request_DebugLabel = 0xFF;
        }

        if (ConfirmFrame && txd_complete) { // Datensatz ohne CRC bestätigen
                SendOutData('B', FC_ADDRESS, 1, (uint8_t*) &ConfirmFrame,
                                sizeof(ConfirmFrame));
                ConfirmFrame = 0;
        }

        if (((DebugData_Interval && CheckDelay(DebugData_Timer)) || request_DebugData)
                        && txd_complete) {
                SendOutData('D', FC_ADDRESS, 1, (uint8_t *) &DebugOut, sizeof(DebugOut));
                DebugData_Timer = SetDelay(DebugData_Interval);
                request_DebugData = FALSE;
        }

        if (((Data3D_Interval && CheckDelay(Data3D_Timer)) || request_Data3D)
                        && txd_complete) {
                SendOutData('C', FC_ADDRESS, 1, (uint8_t *) &Data3D, sizeof(Data3D));
                Data3D.AngleNick = (int16_t) ((10 * angle[PITCH])
                                / GYRO_DEG_FACTOR_PITCHROLL); // convert to multiple of 0.1°
                Data3D.AngleRoll = (int16_t) ((10 * angle[ROLL])
                                / GYRO_DEG_FACTOR_PITCHROLL); // convert to multiple of 0.1°
                Data3D.Heading = (int16_t) ((10 * yawGyroHeading) / GYRO_DEG_FACTOR_YAW); // convert to multiple of 0.1°
                Data3D_Timer = SetDelay(Data3D_Interval);
                request_Data3D = FALSE;
        }

        if (request_ExternalControl && txd_complete) {
                SendOutData('G', FC_ADDRESS, 1, (uint8_t *) &externalControl,
                                sizeof(externalControl));
                request_ExternalControl = FALSE;
        }

#ifdef USE_MK3MAG
        if((CheckDelay(Compass_Timer)) && txd_complete) {
                ToMk3Mag.Attitude[0] = (int16_t)((10 * angle[PITCH]) / GYRO_DEG_FACTOR_PITCHROLL); // approx. 0.1 deg
                ToMk3Mag.Attitude[1] = (int16_t)((10 * angle[ROLL]) / GYRO_DEG_FACTOR_PITCHROLL); // approx. 0.1 deg
                ToMk3Mag.UserParam[0] = dynamicParams.UserParams[0];
                ToMk3Mag.UserParam[1] = dynamicParams.UserParams[1];
                ToMk3Mag.CalState = compassCalState;
                SendOutData('w', MK3MAG_ADDRESS, 1,(uint8_t *) &ToMk3Mag,sizeof(ToMk3Mag));
                // the last state is 5 and should be send only once to avoid multiple flash writing
                if(compassCalState > 4) compassCalState = 0;
                Compass_Timer = SetDelay(99);
        }
#endif

        if (request_MotorTest && txd_complete) {
                SendOutData('T', FC_ADDRESS, 0);
                request_MotorTest = FALSE;
        }

        if (request_PPMChannels && txd_complete) {
                SendOutData('P', FC_ADDRESS, 1, (uint8_t *) &PPM_in, sizeof(PPM_in));
                request_PPMChannels = FALSE;
        }

        if (request_variables && txd_complete) {
                SendOutData('X', FC_ADDRESS, 1, (uint8_t *) &variables, sizeof(variables));
                request_variables = FALSE;
        }
}