marcel/lora_aprs_node_pico
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Decoding APRS frames finished, started with transmitting frames.

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Committer: marcel <marcel@hampi.pe1rxf>
This commit is contained in:
marcel
2022-05-01 18:23:13 +02:00
parent a074eb1ee9
commit 0445ec5ab9
9 changed files with 26812 additions and 23965 deletions
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12
src/Config.h
View File

@@ -28,7 +28,7 @@
int loraPreamble = 8;
int loraCodingRate = 5;
int loraTxPower = 17;
int LoRaPaSelect = 1;
int LoRaPaSelect = 0;
uint32_t loraBandwidth = 125E3;
uint32_t loraFrequency = 433775000;
@@ -56,5 +56,15 @@
const uint8_t SIG_DETECT = 0x01;
const uint8_t SIG_SYNCED = 0x02;
const uint8_t RX_ONGOING = 0x04;
struct aprssettings {
uint8_t MyCall[10] = { 'P','E','1','R','X','F','-','5', 0} ;
uint8_t ServerCall[10] = { 'P','E','1','R','X','F','-','3', 0} ;
uint8_t Destination[10] = { 'A','P','Z','M','D','M', 0} ;
uint8_t Path1[10] = { 0,'I','D','E','1','-', '1', 0} ;
uint8_t Path2[10] = { 0,'I','D','E','2','-', '2', 0} ;
uint8_t FirmwareVersion[20] = { 'V','1',',','C','o','n','t','r', 'o','l','l','e','r',' ','0','1', 0} ;
} AprsSettings;
#endif

248
src/main.cpp
View File

@@ -7,11 +7,19 @@
#include "KISS.h"
bool startRadio();
bool LoadSettings();
void getPacketData(int packetLength);
int compare_strings(uint8_t a[], uint8_t b[]);
bool is_message_for_me (uint8_t data[], uint8_t mycall[]);
void encode_kiss ();
uint16_t decode_packet ();
void ComposeAprsFrame(uint8_t payload[]);
void transmit();
int main() {
uint16_t ServerCommand = 0;
/* Among others, this initializes the USB-serial port at 115200bps 8N1 */
stdio_init_all();
@@ -21,6 +29,8 @@ int main() {
memset(txBuffer, 0, sizeof(txBuffer));
sleep_ms(5000);
LoadSettings();
startRadio();
@@ -40,16 +50,43 @@ int main() {
}
rxBuffer[packetSize-3] = 0;
printf("%s\n", rxBuffer);
encode_kiss();
ServerCommand = decode_packet();
} else {
printf("ERROR: No or corrupted APRS frame.\n");
}
}
if (ServerCommand) {
if (ServerCommand == 1) {
ComposeAprsFrame(AprsSettings.FirmwareVersion);
// Wait for 100ms before responding
sleep_ms(5000);
transmit();
sleep_ms(5000);
transmit();
sleep_ms(5000);
transmit();
sleep_ms(5000);
transmit();
}
ServerCommand = 0;
}
}
return 0;
}
/*
* Load settings from EEPROM
*/
bool LoadSettings()
{
printf("APRS settings:\n");
printf("My call: %s\n", AprsSettings.MyCall);
printf("Server call: %s\n", AprsSettings.ServerCall);
}
/*
* Initializes the LoRa module with the parameters set in config.h
*/
@@ -95,8 +132,9 @@ void getPacketData(int packetLength)
/* Encode 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
*/
void encode_kiss ()
uint16_t decode_packet ()
{
int position = 0;
int cnt = 0;
@@ -105,13 +143,19 @@ void encode_kiss ()
uint8_t aprs_source_address[10];
uint8_t aprs_digi_path[255];
uint8_t aprs_data_field[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));
// Extract from address
cnt = 0;
@@ -184,8 +228,202 @@ void encode_kiss ()
aprs_digis[number_of_digipeaters][cnt] = 0;
}
if (valid_apsr_data)
if (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 ( is_message_for_me(aprs_data_field, AprsSettings.MyCall) )
{
// Extract aprs message from data field
position=11;
while( aprs_data_field[position] != 0 )
{
aprs_message[position-11] = aprs_data_field[position];
position++;
}
// Extract command and acknowledge number (if present)
cnt = 0;
position = 0;
while( aprs_message[position] != 0 )
{
if ( aprs_message[position] == '{' ) {
aprs_acknowledge_number[cnt++] = ':';
while ( AprsSettings.ServerCall[cnt-1] != 0 )
{
aprs_acknowledge_number[cnt] = AprsSettings.ServerCall[cnt-1];
cnt++;
}
//Fill with spaces
while ( cnt<10 )
{
aprs_acknowledge_number[cnt++] = ' ';
}
aprs_acknowledge_number[cnt++] = ':';
aprs_acknowledge_number[cnt++] = 'a';
aprs_acknowledge_number[cnt++] = 'c';
aprs_acknowledge_number[cnt++] = 'k';
aprs_acknowledge_request = true;
}
// Calculate server command
if (!aprs_acknowledge_request) {
aprs_server_command = 10*aprs_server_command + aprs_message[position]-48;
}
position++;
if (aprs_acknowledge_request) {
aprs_acknowledge_number[cnt++] = aprs_message[position];
}
}
aprs_acknowledge_number[cnt] = 0;
}
}
printf("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])
{
printf("Message from server: %s (command %u)\n", aprs_message, aprs_server_command);
if (aprs_acknowledge_request) {
ComposeAprsFrame(aprs_acknowledge_number);
// Wait for 100ms before responding with acknowledge
sleep_ms(100);
transmit();
printf("Acknowledge request: %s\n", aprs_acknowledge_number);
}
}
}
else
printf("Error decoding APRS frame.");
return (aprs_server_command);
}
/*
* Checks if aprs datafield contains message and if message is for us
*
* Returns: 0 if datafield contains no message for us
* 1 if datafield contains a message for us
*/
bool is_message_for_me (uint8_t data[], uint8_t mycall[])
{
// A variable to iterate through the strings
int i=0;
if (data[0] == ':' && data[10] == ':')
{
while( i<9 && mycall[i] != 0 ) {
if (data[i+1] != mycall[i]) {
return (0);
}
i++;
}
return (1);
}
return (0);
}
int compare_strings(uint8_t a[], uint8_t b[])
{
// A variable to iterate through the strings
int i = 0;
while (a[i] == b[i])
{
// If either of the strings reaches the end
// we stop the loop
if (a[i] == '\0' || b[i] == '\0')
break;
i++;
}
// We check if both the strings have been compared
// till the end or not
// If the strings are compared till the end they are equal
if (a[i] == '\0' && b[i] == '\0')
return 0;
else
{
if(a[i] == '\0')
return -1*(b[i]);
else if(b[i] == '\0')
return a[i];
else
return (a[i]-b[i]);
}
}
void ComposeAprsFrame(uint8_t payload[])
{
uint16_t BufferPosition = 0;
uint16_t cnt = 0;
// APRS header
txBuffer[BufferPosition++] = '<';
txBuffer[BufferPosition++] = 0xff;
txBuffer[BufferPosition++] = 0x01;
while ( AprsSettings.MyCall[cnt] != 0 && BufferPosition<MTU )
{
txBuffer[BufferPosition++] = AprsSettings.MyCall[cnt];
cnt++;
}
txBuffer[BufferPosition++] = '>';
cnt=0;
while ( AprsSettings.Destination[cnt] != 0 && BufferPosition<MTU )
{
txBuffer[BufferPosition++] = AprsSettings.Destination[cnt];
cnt++;
}
if ( AprsSettings.Path1[0] != 0)
txBuffer[BufferPosition++] = ',';
cnt=0;
while ( AprsSettings.Path1[cnt] != 0 && BufferPosition<MTU )
{
txBuffer[BufferPosition++] = AprsSettings.Path1[cnt];
cnt++;
}
if ( AprsSettings.Path2[0] != 0)
txBuffer[BufferPosition++] = ',';
cnt=0;
while ( AprsSettings.Path2[cnt] != 0 && BufferPosition<MTU )
{
txBuffer[BufferPosition++] = AprsSettings.Path2[cnt];
cnt++;
}
txBuffer[BufferPosition++] = ':';
cnt=0;
while ( payload[cnt] != 0 && BufferPosition<MTU )
{
txBuffer[BufferPosition++] = payload[cnt];
cnt++;
}
printf("%s\n", txBuffer);
}
void transmit() {
uint16_t position = 0;
LoRa.beginPacket();
while( txBuffer[position] != 0 )
{
LoRa.write(txBuffer[position]);
position++;
}
LoRa.endPacket();
LoRa.receive();
}