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Received LoRa frames can now be converted to AX25 frames.

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This commit is contained in:
marcel
2022-05-12 17:52:01 +02:00
parent 414ddbd9c8
commit 64877d828e
15 changed files with 31759 additions and 30837 deletions
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2
src/Config.h
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@@ -92,5 +92,7 @@
uint8_t KissMode = OFF;
} Status;
#endif

189
src/kiss.cpp
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@@ -1,6 +1,191 @@
#include "kiss.h"
uint16_t KissClass::EncodeFrame(void)
/*
* KISS encoder uses two steps:
*
* Step 1: encodes the LoRa APRS frame into an AX.25 frame. DONE
* Step 2: encapsulates the AX.25 frame into a KISS frame. TODO
*
* struct aprs_frame {
* uint8_t source_address[10];
* uint8_t digi_path[255];
* uint8_t data_field[255];
* uint8_t message[255];
* uint8_t digis[10][10];
* uint8_t acknowledge_number[255];
* bool acknowledge_request = false;
* uint16_t server_command = 0;
* uint16_t number_of_digipeaters = 0;
*
* uint8_t valid_apsr_data = false;
* };
*
*/
uint16_t KissClass::EncodeFrame(struct aprs_frame *aprsframe, struct ax25_frame *ax25frame)
{
return 100;
uint8_t *encoded_call;
uint16_t cnt=0;
uint16_t position = 0;
uint8_t digi_cnt = 0;
// Destination call
//printf("Destination: ");
encoded_call = EncodeCall(aprsframe->digis[0]);
cnt = 0;
while (cnt < 7)
{
ax25frame->complete[position] = *(encoded_call+cnt);
////printf("0x%X ", *(encoded_call+cnt));
//printf("0x%X ", ax25frame->complete[position]);
cnt++;
position++;
}
//printf("\n");
// Source call
//printf("Source: ");
cnt=0;
encoded_call = EncodeCall(aprsframe->source_address);
while (cnt < 7)
{
ax25frame->complete[position] = *(encoded_call+cnt);
////printf("0x%X ", *(encoded_call+cnt));
//printf("0x%X ", ax25frame->complete[position]);
cnt++;
position++;
}
//printf("\n");
// No digipeaters in path, so destination is the last call and therefore the 'last' flag should be set
if (aprsframe->number_of_digipeaters == 0)
{
ax25frame->complete[position-1] |= 0x01;
}
else
{
// Path (digipeaters)
//printf("Path: ");
cnt=0;
digi_cnt = 1; // Start at position 1 as position 0 contains destination (which we already encoded)
while (aprsframe->number_of_digipeaters-- != 0) {
while (cnt < 7) {
encoded_call = EncodeCall(aprsframe->digis[digi_cnt]);
ax25frame->complete[position] = *(encoded_call+cnt);
////printf("0x%X ", *(encoded_call+cnt));
//printf("0x%X ", ax25frame->complete[position]);
cnt++;
position++;
}
digi_cnt++;
cnt = 0;
}
//printf("\n");
// Set 'last' flag
ax25frame->complete[position-1] |= 0x01;
}
// Add control fields
ax25frame->complete[position++] = 0x03;
ax25frame->complete[position++] = 0xF0;
// All the dificult bits are done, now we just add the payload.
//printf("Data:");
cnt = 0;
while (aprsframe->data_field[cnt] != 0 && cnt < 256) {
ax25frame->complete[position] = aprsframe->data_field[cnt];
//printf("0x%X ", ax25frame->complete[position]);
cnt++;
position++;
}
printf( "\n");
// Store length of AX25 frame
ax25frame->lenght = position;
/*cnt=0;
while (ax25frame->lenght-- != 0)
{
printf("0x%X ", ax25frame->complete[cnt]);
cnt++;
}
printf("\n");
*/
//fwrite(ax25frame->complete, 1, ax25frame->lenght, stdout);
return 0;
}
/*
* Encodes call according to AX.25 specs.
*
* input : string with call and ssid as readable characters
* output: pointer to memory location (7 bytes with the encoded call)
*
*/
uint8_t * KissClass::EncodeCall(uint8_t string[])
{
uint8_t position = 0;
uint8_t cnt = 0;
static uint8_t call[7] = { 0,0,0,0,0,0,0} ;
uint8_t ssid = 0;
// extract call
while( string[position] != 0 || cnt < 6)
{
call[cnt++] = string[position] << 1;
if ( string[position] == '-') {
position++;
break;
}
position++;
}
// pad with spaces to a length of 6
while( cnt < 6 )
{
call[cnt++] = ' ' << 1;
}
// extract ssid
cnt=0;
while( string[position] != 0 )
{
if (string[position] >= 48 && string[position] <= 57) {
ssid = 10*ssid + string[position]-48;
position++;
}
}
// if asterix is pressent in string, than the message has been repeated, so set the 'has been repeated' flag in the ssid register
position = 0;
while( string[position] != 0)
{
if (string[position] == '*')
ssid = 0b10000000;
position++;
}
ssid = (ssid << 1) | 0b01100000;
// add encoded ssid to encoded call array
call[6] = ssid;
/*
//printf("SSID: 0x%X\n", ssid);
cnt = 0;
while (cnt < 7)
{
//printf("0x%X ", call[cnt++]);
}
//printf("\n");
*/
return call;
}

24
src/kiss.h
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@@ -22,10 +22,32 @@
#define ERROR_TXFAILED 0x02
#define ERROR_QUEUE_FULL 0x04
struct aprs_frame {
uint8_t source_address[10];
uint8_t digi_path[255];
uint8_t data_field[255];
uint8_t message[255];
uint8_t digis[10][10];
uint8_t acknowledge_number[255];
bool acknowledge_request = false;
uint16_t server_command = 0;
uint16_t number_of_digipeaters = 0;
uint8_t valid_apsr_data = false;
};
struct ax25_frame {
uint8_t complete[512];
uint16_t lenght = 0;
uint8_t kiss_frame[512];
};
class KissClass
{
public:
uint16_t EncodeFrame(void);
uint16_t EncodeFrame(struct aprs_frame *frame, struct ax25_frame *ax25frame);
private:
uint8_t * EncodeCall(uint8_t string[]);
};
#endif

131
src/main.cpp
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@@ -258,6 +258,11 @@ void ProcessSerialInput(char string[])
else if (strcmp(command, "kiss") == 0) {
log_out("Entering KISS mode.\n");
log_out("You can exit KISS mode via KISS command <0xC0 0xFF 0xC0>\n");
// disable CRLF convertion, so we can write raw data to the USB port in KISS mode
stdio_set_translate_crlf(&stdio_usb, false);
//fwrite(buf, 1, sizeof(buf), stdout); // seems not to work
//putchar(49);
Status.KissMode = ON;
}
@@ -624,58 +629,56 @@ void getPacketData(int packetLength)
rxBuffer[position] = 0;
}
/* Encode LoRa APRS frame: extract source call, digipeater path and data field. At the same time, check for data corruption
/* Decode LoRa APRS frame: extract source call, digipeater path and data field. At the same time, check for data corruption
*
* If frame is a message from the server it returns the command from this server
*
* The resulting fields are stored in struct AprsFrame and given to the kiss-routines for further processing (when in kiss-mode)
*/
uint16_t decode_packet ()
{
int position = 0;
int cnt = 0;
int number_of_digipeaters = 0;
char valid_apsr_data = false;
uint8_t aprs_source_address[10];
uint8_t aprs_digi_path[255];
uint8_t aprs_data_field[255];
uint8_t aprs_message[255];
uint8_t aprs_digis[10][10];
uint8_t aprs_acknowledge_number[255];
bool aprs_acknowledge_request = false;
uint16_t aprs_server_command = 0;
memset(aprs_source_address, 0, sizeof(aprs_source_address));
memset(aprs_digi_path, 0, sizeof(aprs_digi_path));
memset(aprs_data_field, 0, sizeof(aprs_data_field));
memset(aprs_message, 0, sizeof(aprs_message));
memset(aprs_digis, 0, sizeof(aprs_digis));
memset(aprs_acknowledge_number, 0, sizeof(aprs_acknowledge_number));
struct aprs_frame AprsFrame; //defined in kiss.h
struct ax25_frame AX25Frame; //defined in kiss.h
memset(AprsFrame.source_address, 0, sizeof(AprsFrame.source_address));
memset(AprsFrame.digi_path, 0, sizeof(AprsFrame.digi_path));
memset(AprsFrame.data_field, 0, sizeof(AprsFrame.data_field));
memset(AprsFrame.message, 0, sizeof(AprsFrame.message));
memset(AprsFrame.digis, 0, sizeof(AprsFrame.digis));
memset(AprsFrame.acknowledge_number, 0, sizeof(AprsFrame.acknowledge_number));
AprsFrame.acknowledge_request = false;
AprsFrame.server_command = 0;
AprsFrame.number_of_digipeaters = 0;
AprsFrame.valid_apsr_data = false;
// Extract from address
cnt = 0;
while( rxBuffer[position] != 0 )
{
aprs_source_address[cnt++] = rxBuffer[position];
AprsFrame.source_address[cnt++] = rxBuffer[position];
if ( rxBuffer[position] == '>' && position < 10 ) {
aprs_source_address[cnt-1] = 0;
valid_apsr_data = true;
AprsFrame.source_address[cnt-1] = 0;
AprsFrame.valid_apsr_data = true;
position++;
break;
}
position++;
}
if (valid_apsr_data == true)
if (AprsFrame.valid_apsr_data == true)
{
// Extract digi path
valid_apsr_data = false;
AprsFrame.valid_apsr_data = false;
cnt = 0;
while( rxBuffer[position] != 0 )
{
aprs_digi_path[cnt++] = rxBuffer[position];
AprsFrame.digi_path[cnt++] = rxBuffer[position];
if ( rxBuffer[position] == ':' ) {
aprs_digi_path[cnt-1] = 0;
valid_apsr_data = true;
AprsFrame.digi_path[cnt-1] = 0;
AprsFrame.valid_apsr_data = true;
position++;
break;
}
@@ -684,90 +687,96 @@ uint16_t decode_packet ()
}
if (valid_apsr_data == true)
if (AprsFrame.valid_apsr_data == true)
{
// Extract data field
cnt = 0;
while( rxBuffer[position] != 0 )
{
aprs_data_field[cnt++] = rxBuffer[position];
AprsFrame.data_field[cnt++] = rxBuffer[position];
position++;
}
aprs_data_field[cnt] = 0;
AprsFrame.data_field[cnt] = 0;
}
if (valid_apsr_data == true)
if (AprsFrame.valid_apsr_data == true)
{
// Extract digis from digi-path
cnt = 0;
position = 0;
number_of_digipeaters = 0;
while( aprs_digi_path[position] != 0 )
AprsFrame.number_of_digipeaters = 0;
while( AprsFrame.digi_path[position] != 0 )
{
aprs_digis[number_of_digipeaters][cnt++] = aprs_digi_path[position];
if ( aprs_digi_path[position] == ',' && cnt < 10 ) {
aprs_digis[number_of_digipeaters][cnt-1] = 0;
if (++number_of_digipeaters > 9) {
valid_apsr_data = false;
AprsFrame.digis[AprsFrame.number_of_digipeaters][cnt++] = AprsFrame.digi_path[position];
if ( AprsFrame.digi_path[position] == ',' && cnt < 10 ) {
AprsFrame.digis[AprsFrame.number_of_digipeaters][cnt-1] = 0;
if (++AprsFrame.number_of_digipeaters > 9) {
AprsFrame.valid_apsr_data = false;
break;
}
cnt = 0;
}
position++;
}
aprs_digis[number_of_digipeaters][cnt] = 0;
AprsFrame.digis[AprsFrame.number_of_digipeaters][cnt] = 0;
}
if (valid_apsr_data) {
if (AprsFrame.valid_apsr_data) {
// Check if packet comes from our server and if so, check if it is a message for us.
if ( !compare_strings(aprs_source_address, AprsSettings.ServerCall) ) {
if ( !compare_strings(AprsFrame.source_address, AprsSettings.ServerCall) ) {
if ( is_message_for_me(aprs_data_field, AprsSettings.MyCall) )
if ( is_message_for_me(AprsFrame.data_field, AprsSettings.MyCall) )
{
// Extract aprs message from data field
position=11;
while( aprs_data_field[position] != 0 )
while( AprsFrame.data_field[position] != 0 )
{
aprs_message[position-11] = aprs_data_field[position];
AprsFrame.message[position-11] = AprsFrame.data_field[position];
position++;
}
AprsFrame.message[position-11] = 0; // Terminate string
// Extract command and acknowledge number (if present)
cnt = 0;
position = 0;
while( aprs_message[position] != 0 )
while( AprsFrame.message[position] != 0 )
{
if ( aprs_message[position] == '{' ) {
if ( AprsFrame.message[position] == '{' ) {
aprs_acknowledge_number[cnt++] = 'a';
aprs_acknowledge_number[cnt++] = 'c';
aprs_acknowledge_number[cnt++] = 'k';
aprs_acknowledge_request = true;
AprsFrame.acknowledge_number[cnt++] = 'a';
AprsFrame.acknowledge_number[cnt++] = 'c';
AprsFrame.acknowledge_number[cnt++] = 'k';
AprsFrame.acknowledge_request = true;
}
// Calculate server command
if (!aprs_acknowledge_request) {
aprs_server_command = 10*aprs_server_command + aprs_message[position]-48;
if (!AprsFrame.acknowledge_request) {
AprsFrame.server_command = 10*AprsFrame.server_command + AprsFrame.message[position]-48;
}
position++;
if (aprs_acknowledge_request) {
aprs_acknowledge_number[cnt++] = aprs_message[position];
if (AprsFrame.acknowledge_request) {
AprsFrame.acknowledge_number[cnt++] = AprsFrame.message[position];
}
}
aprs_acknowledge_number[cnt] = 0;
AprsFrame.acknowledge_number[cnt] = 0;
}
}
log_out("Source address: %s\nDigipeaters (%u): %s %s %s %s\nData: %s\n", aprs_source_address, number_of_digipeaters+1, aprs_digis[0], aprs_digis[1], aprs_digis[2], aprs_digis[3], aprs_data_field);
if (aprs_message[0])
log_out("Source address: %s\nDigipeaters (%u): %s %s %s %s\nData: %s\n", AprsFrame.source_address, AprsFrame.number_of_digipeaters+1, AprsFrame.digis[0], AprsFrame.digis[1], AprsFrame.digis[2], AprsFrame.digis[3], AprsFrame.data_field);
// If in KISS mode the struct AprsFrame is handed over to the KISS encoder
if (Status.KissMode == 0)
Kiss.EncodeFrame(&AprsFrame, &AX25Frame);
if (AprsFrame.message[0])
{
log_out("Message from server: %s (command %u)\n", aprs_message, aprs_server_command);
if (aprs_acknowledge_request) {
ComposeAprsFrame(aprs_acknowledge_number);
log_out("Acknowledge request: %s\n", aprs_acknowledge_number);
log_out("Message from server: %s (command %u)\n", AprsFrame.message, AprsFrame.server_command);
if (AprsFrame.acknowledge_request) {
ComposeAprsFrame(AprsFrame.acknowledge_number);
log_out("Acknowledge request: %s\n", AprsFrame.acknowledge_number);
}
}
@@ -776,7 +785,7 @@ uint16_t decode_packet ()
else
log_out("Error decoding APRS frame.");
return (aprs_server_command);
return (AprsFrame.server_command);
}
/*