Add support for APRS weather reports. Fix incorrect atmospheric pressure values with BMP280.

README.md

@@ -58,6 +58,7 @@ The main features the RS41ng firmware are:
 
 * Support for multiple transmission modes:
   * Standard 1200-baud APRS
+    * Option to transmit APRS weather reports using readings from an external BMP280 sensor
   * [Horus 4FSK v1 and v2 modes](https://github.com/projecthorus/horusdemodlib/wiki) that has improved performance compared to APRS or RTTY
     * There is an option to use continuous transmit mode (for either V1 or V2 mode), which helps with receiver frequency synchronization and improves reception.
   * Morse code (CW)

src/bmp280_handler.c

@@ -40,7 +40,8 @@ bool bmp280_read(int32_t *temperature_celsius_100, uint32_t *pressure_mbar_100,
         *temperature_celsius_100 = temperature_raw;
     }
     if (pressure_mbar_100) {
-        *pressure_mbar_100 = (uint32_t) (((float) pressure_raw) * 100.0f / 256.0f);
+        // Pressure unit is Pascal (= mbar * 100) * 256
+        *pressure_mbar_100 = (uint32_t) (((float) pressure_raw) / 256.0f);
     }
     if (humidity_percentage_100) {
         *humidity_percentage_100 = (uint32_t) (((float) humidity_raw) * 100.0f / 1024.0f);

src/codecs/aprs/aprs.c

@@ -1,19 +1,10 @@
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 #include "aprs.h"
 
-/**
- * TODO: add function to generate weather report
- *
- * Examples:
- * 2019-11-27 04:37:21 EET: OH2NJR>APRS,WIDE1-1,qAR,OH2HCY-2:;434.700-C*111111z6030.65N/02444.84Er434.700MHz T118 -200 R50k OH2RUC Nurmijarvi
- * 2019-11-27 04:52:08 EET: OH2NJR>APX210,TCPIP*,qAC,APRSFI-I3:=6030.35N/02443.91E_154/001g002t034r000P000p000b10029
- */
-
 volatile uint16_t aprs_packet_counter = 0;
 
-static void convert_degrees_to_dmh(long x, int8_t *degrees, uint8_t *minutes, uint8_t *h_minutes)
+void convert_degrees_to_dmh(long x, int8_t *degrees, uint8_t *minutes, uint8_t *h_minutes)
 {
     uint8_t sign = (uint8_t) (x > 0 ? 1 : 0);
     if (!sign) {
@@ -29,47 +20,7 @@ static void convert_degrees_to_dmh(long x, int8_t *degrees, uint8_t *minutes, ui
     }
 }
 
-size_t aprs_generate_position(uint8_t *payload, size_t length, telemetry_data *data,
-        char symbol_table, char symbol, bool include_timestamp, char *comment)
+void aprs_generate_timestamp(char *timestamp, size_t length, telemetry_data *data)
 {
-    char timestamp[12];
-
-    int8_t la_degrees, lo_degrees;
-    uint8_t la_minutes, la_h_minutes, lo_minutes, lo_h_minutes;
-
-    convert_degrees_to_dmh(data->gps.latitude_degrees_1000000 / 10, &la_degrees, &la_minutes, &la_h_minutes);
-    convert_degrees_to_dmh(data->gps.longitude_degrees_1000000 / 10, &lo_degrees, &lo_minutes, &lo_h_minutes);
-
-    int16_t heading_degrees = (int16_t) ((float) data->gps.heading_degrees_100000 / 100000.0f);
-    int16_t ground_speed_knots = (int16_t) (((float) data->gps.ground_speed_cm_per_second / 100.0f) * 3.6f / 1.852f);
-    int32_t altitude_feet = (data->gps.altitude_mm / 1000) * 3280 / 1000;
-
-    if (include_timestamp) {
-        snprintf(timestamp, sizeof(timestamp), "/%02d%02d%02dz", data->gps.hours, data->gps.minutes, data->gps.seconds);
-    } else {
-        strncpy(timestamp, "!", sizeof(timestamp));
-    }
-
-    aprs_packet_counter++;
-
-    return snprintf((char *) payload,
-            length,
-            ("%s%02d%02d.%02u%c%c%03d%02u.%02u%c%c%03d/%03d/A=%06d/P%dS%dT%02dV%04dC%02d%s"),
-            timestamp,
-            abs(la_degrees), la_minutes, la_h_minutes,
-            la_degrees > 0 ? 'N' : 'S',
-            symbol_table,
-            abs(lo_degrees), lo_minutes, lo_h_minutes,
-            lo_degrees > 0 ? 'E' : 'W',
-            symbol,
-            heading_degrees,
-            ground_speed_knots,
-            (int) altitude_feet,
-            aprs_packet_counter,
-            data->gps.satellites_visible,
-            (int) data->internal_temperature_celsius_100 / 100,
-            data->battery_voltage_millivolts,
-            (int16_t) ((float) data->gps.climb_cm_per_second / 100.0f),
-            comment
-    );
+    snprintf(timestamp, length, "/%02d%02d%02dz", data->gps.hours, data->gps.minutes, data->gps.seconds);
 }

src/codecs/aprs/aprs.h

@@ -7,7 +7,9 @@
 #include "gps.h"
 #include "telemetry.h"
 
-size_t aprs_generate_position(uint8_t *payload, size_t length, telemetry_data *data,
-        char symbol_table, char symbol, bool include_timestamp, char *comment);
+void convert_degrees_to_dmh(long x, int8_t *degrees, uint8_t *minutes, uint8_t *h_minutes);
+void aprs_generate_timestamp(char *timestamp, size_t length, telemetry_data *data);
+
+extern volatile uint16_t aprs_packet_counter;
 
 #endif

src/codecs/aprs/aprs_position.c

@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aprs.h"
+#include "aprs_position.h"
+
+size_t aprs_generate_position(uint8_t *payload, size_t length, telemetry_data *data,
+        char symbol_table, char symbol, bool include_timestamp, char *comment)
+{
+    char timestamp[12];
+
+    int8_t la_degrees, lo_degrees;
+    uint8_t la_minutes, la_h_minutes, lo_minutes, lo_h_minutes;
+
+    convert_degrees_to_dmh(data->gps.latitude_degrees_1000000 / 10, &la_degrees, &la_minutes, &la_h_minutes);
+    convert_degrees_to_dmh(data->gps.longitude_degrees_1000000 / 10, &lo_degrees, &lo_minutes, &lo_h_minutes);
+
+    int16_t heading_degrees = (int16_t) ((float) data->gps.heading_degrees_100000 / 100000.0f);
+    int16_t ground_speed_knots = (int16_t) (((float) data->gps.ground_speed_cm_per_second / 100.0f) * 3.6f / 1.852f);
+    int32_t altitude_feet = (data->gps.altitude_mm / 1000) * 3280 / 1000;
+
+    if (include_timestamp) {
+        aprs_generate_timestamp(timestamp, sizeof(timestamp), data);
+    } else {
+        strncpy(timestamp, "!", sizeof(timestamp));
+    }
+
+    aprs_packet_counter++;
+
+    return snprintf((char *) payload,
+            length,
+            ("%s%02d%02d.%02u%c%c%03d%02u.%02u%c%c%03d/%03d/A=%06d/P%dS%dT%02dV%04dC%02d%s"),
+            timestamp,
+            abs(la_degrees), la_minutes, la_h_minutes,
+            la_degrees > 0 ? 'N' : 'S',
+            symbol_table,
+            abs(lo_degrees), lo_minutes, lo_h_minutes,
+            lo_degrees > 0 ? 'E' : 'W',
+            symbol,
+            heading_degrees,
+            ground_speed_knots,
+            (int) altitude_feet,
+            aprs_packet_counter,
+            data->gps.satellites_visible,
+            (int) data->internal_temperature_celsius_100 / 100,
+            data->battery_voltage_millivolts,
+            (int16_t) ((float) data->gps.climb_cm_per_second / 100.0f),
+            comment
+    );
+}

src/codecs/aprs/aprs_position.h

@@ -0,0 +1,13 @@
+#ifndef __APRS_POSITION_H
+#define __APRS_POSITION_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "gps.h"
+#include "telemetry.h"
+
+size_t aprs_generate_position(uint8_t *payload, size_t length, telemetry_data *data,
+        char symbol_table, char symbol, bool include_timestamp, char *comment);
+
+#endif

src/codecs/aprs/aprs_weather.c

@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aprs.h"
+#include "aprs_weather.h"
+
+size_t aprs_generate_weather_report(uint8_t *payload, size_t length, telemetry_data *data,
+        bool include_timestamp, char *comment)
+{
+    char timestamp[12];
+
+    int8_t la_degrees, lo_degrees;
+    uint8_t la_minutes, la_h_minutes, lo_minutes, lo_h_minutes;
+
+    convert_degrees_to_dmh(data->gps.latitude_degrees_1000000 / 10, &la_degrees, &la_minutes, &la_h_minutes);
+    convert_degrees_to_dmh(data->gps.longitude_degrees_1000000 / 10, &lo_degrees, &lo_minutes, &lo_h_minutes);
+
+    if (include_timestamp) {
+        aprs_generate_timestamp(timestamp, sizeof(timestamp), data);
+    } else {
+        strncpy(timestamp, "!", sizeof(timestamp));
+    }
+
+    int32_t temperature_fahrenheits = (data->temperature_celsius_100 * 9 / 5) / 100 + 32;
+    uint32_t pressure_mbar_10 = data->pressure_mbar_100 / 10;
+    uint16_t humidity_percentage = data->humidity_percentage_100 / 100;
+    if (humidity_percentage > 99) {
+        humidity_percentage = 0; // Zero represents 100%
+    } else if (humidity_percentage < 1) {
+        humidity_percentage = 1;
+    }
+
+    aprs_packet_counter++;
+
+    return snprintf((char *) payload,
+            length,
+            ("%s%02d%02d.%02u%c%c%03d%02u.%02u%c%c.../...g...t%03dh%02ub%05u%s"),
+            timestamp,
+            abs(la_degrees), la_minutes, la_h_minutes,
+            la_degrees > 0 ? 'N' : 'S',
+            '/', // Primary symbol table
+            abs(lo_degrees), lo_minutes, lo_h_minutes,
+            lo_degrees > 0 ? 'E' : 'W',
+            '_', // Weather station symbol
+            (int) temperature_fahrenheits,
+            (unsigned int) humidity_percentage,
+            (unsigned int) pressure_mbar_10,
+            comment
+    );
+}

src/codecs/aprs/aprs_weather.h

@@ -0,0 +1,13 @@
+#ifndef __APRS_WEATHER_H
+#define __APRS_WEATHER_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "gps.h"
+#include "telemetry.h"
+
+size_t aprs_generate_weather_report(uint8_t *payload, size_t length, telemetry_data *data,
+        bool include_timestamp, char *comment);
+
+#endif

src/config.c

@@ -66,6 +66,7 @@ char *aprs_comment_templates[] = {
 //        " B$bu $teC $hu% $prmb - " APRS_COMMENT,
 //        " B$bu $loc12 $hh:$mm:$ss - " APRS_COMMENT,
         " $loc12 - " APRS_COMMENT,
+//        " " APRS_COMMENT,
         NULL
 };
 

src/config.h

@@ -31,7 +31,7 @@
 #define LOCATOR_PAIR_COUNT_FULL 6 // max. 6 (12 characters WWL)
 
 // Delay after transmission for modes that do not use time synchronization. Zero delay allows continuous transmit mode for Horus V1 and V2.
-#define RADIO_POST_TRANSMIT_DELAY_MS 0
+#define RADIO_POST_TRANSMIT_DELAY_MS 1000
 
 // Threshold for time-synchronized modes regarding how far from scheduled transmission time the transmission is still allowed
 #define RADIO_TIME_SYNC_THRESHOLD_MS 2000
@@ -54,7 +54,7 @@
 // Which modes to transmit using the built-in Si4032 transmitter chip
 #define RADIO_SI4032_TX_CW true
 #define RADIO_SI4032_TX_APRS true
-#define RADIO_SI4032_TX_HORUS_V1 true
+#define RADIO_SI4032_TX_HORUS_V1 false
 #define RADIO_SI4032_TX_HORUS_V2 true
 
 // Continuous transmit mode can be enabled for *either* Horus V1 or V2, but not both. This disables all other transmission modes.
@@ -80,13 +80,13 @@
 
 // Which modes to transmit using an externally connected Si5351 chip in the I²C bus
 #define RADIO_SI5351_TX_CW true
-#define RADIO_SI5351_TX_HORUS_V1 true
+#define RADIO_SI5351_TX_HORUS_V1 false
 #define RADIO_SI5351_TX_HORUS_V2 true
 #define RADIO_SI5351_TX_JT9 false
 #define RADIO_SI5351_TX_JT65 false
 #define RADIO_SI5351_TX_JT4 false
 #define RADIO_SI5351_TX_WSPR false
-#define RADIO_SI5351_TX_FSQ true
+#define RADIO_SI5351_TX_FSQ false
 #define RADIO_SI5351_TX_FT8 false
 
 // Transmit frequencies for the Si5351 transmitter modes
@@ -132,6 +132,8 @@
 #define APRS_RELAYS "WIDE1-1,WIDE2-1"
 #define APRS_DESTINATION "APZ41N"
 #define APRS_DESTINATION_SSID '0'
+// Generate an APRS weather report instead of a position report. This will override the APRS symbol with the weather station symbol.
+#define APRS_WEATHER_REPORT_ENABLE false
 
 // Schedule transmission every N seconds, counting from beginning of an hour (based on GPS time). Set to zero to disable time sync.
 #define APRS_TIME_SYNC_SECONDS 0

src/radio.c

@@ -15,7 +15,8 @@
 #include "radio_si4032.h"
 #include "radio_si5351.h"
 #include "radio_payload_cw.h"
-#include "radio_payload_aprs.h"
+#include "radio_payload_aprs_position.h"
+#include "radio_payload_aprs_weather.h"
 #include "radio_payload_horus_v1.h"
 #include "radio_payload_horus_v2.h"
 #include "radio_payload_wspr.h"
@@ -95,7 +96,11 @@ radio_transmit_entry radio_transmit_schedule[] = {
                 .frequency = RADIO_SI4032_TX_FREQUENCY_APRS_1200,
                 .tx_power = RADIO_SI4032_TX_POWER,
                 .symbol_rate = 1200,
-                .payload_encoder = &radio_aprs_payload_encoder,
+#if APRS_WEATHER_REPORT_ENABLE
+                .payload_encoder = &radio_aprs_weather_report_payload_encoder,
+#else
+                .payload_encoder = &radio_aprs_position_payload_encoder,
+#endif
                 .fsk_encoder_api = &bell_fsk_encoder_api,
         },
         {

src/radio_payload_aprs.h

@@ -1,8 +0,0 @@
-#ifndef __RADIO_PAYLOAD_APRS_H
-#define __RADIO_PAYLOAD_APRS_H
-
-#include "payload.h"
-
-extern payload_encoder radio_aprs_payload_encoder;
-
-#endif

src/radio_payload_aprs_position.c

@@ -1,13 +1,13 @@
 #include <stdint.h>
 
 #include "codecs/ax25/ax25.h"
-#include "codecs/aprs/aprs.h"
+#include "codecs/aprs/aprs_position.h"
 #include "config.h"
 #include "telemetry.h"
 #include "log.h"
-#include "radio_payload_aprs.h"
+#include "radio_payload_aprs_position.h"
 
-uint16_t radio_aprs_encode(uint8_t *payload, uint16_t length, telemetry_data *telemetry_data, char *message)
+uint16_t radio_aprs_position_encode(uint8_t *payload, uint16_t length, telemetry_data *telemetry_data, char *message)
 {
     uint8_t aprs_packet[RADIO_PAYLOAD_MAX_LENGTH];
 
@@ -20,6 +20,6 @@ uint16_t radio_aprs_encode(uint8_t *payload, uint16_t length, telemetry_data *te
             (char *) aprs_packet, length, payload);
 }
 
-payload_encoder radio_aprs_payload_encoder = {
-        .encode = radio_aprs_encode,
+payload_encoder radio_aprs_position_payload_encoder = {
+        .encode = radio_aprs_position_encode,
 };

src/radio_payload_aprs_position.h

@@ -0,0 +1,8 @@
+#ifndef __RADIO_PAYLOAD_APRS_POSITION_H
+#define __RADIO_PAYLOAD_APRS_POSITION_H
+
+#include "payload.h"
+
+extern payload_encoder radio_aprs_position_payload_encoder;
+
+#endif

src/radio_payload_aprs_weather.c

@@ -0,0 +1,24 @@
+#include <stdint.h>
+
+#include "codecs/ax25/ax25.h"
+#include "codecs/aprs/aprs_weather.h"
+#include "config.h"
+#include "telemetry.h"
+#include "log.h"
+#include "radio_payload_aprs_weather.h"
+
+uint16_t radio_aprs_weather_report_encode(uint8_t *payload, uint16_t length, telemetry_data *telemetry_data, char *message)
+{
+    uint8_t aprs_packet[RADIO_PAYLOAD_MAX_LENGTH];
+
+    aprs_generate_weather_report(aprs_packet, sizeof(aprs_packet), telemetry_data,true, message);
+
+    log_debug("APRS packet: %s\n", aprs_packet);
+
+    return ax25_encode_packet_aprs(APRS_CALLSIGN, APRS_SSID, APRS_DESTINATION, APRS_DESTINATION_SSID, APRS_RELAYS,
+            (char *) aprs_packet, length, payload);
+}
+
+payload_encoder radio_aprs_weather_report_payload_encoder = {
+        .encode = radio_aprs_weather_report_encode,
+};

src/radio_payload_aprs_weather.h

@@ -0,0 +1,8 @@
+#ifndef __RADIO_PAYLOAD_APRS_WEATHER_H
+#define __RADIO_PAYLOAD_APRS_WEATHER_H
+
+#include "payload.h"
+
+extern payload_encoder radio_aprs_weather_report_payload_encoder;
+
+#endif

tests/bell_test.c

@@ -2,7 +2,7 @@
 #include <stdbool.h>
 
 #include "codecs/bell/bell.h"
-#include "codecs/aprs/aprs.h"
+#include "codecs/aprs/aprs_position.h"
 #include "codecs/ax25/ax25.h"
 #include "telemetry.h"
 #include "config.h"

tests/morse_test.c

@@ -4,7 +4,7 @@
 #include "codecs/morse/morse.h"
 #include "config.h"
 
-int main(void)
+int main4(void)
 {
     fsk_encoder morse;
 

tests/template_test.c

@@ -3,14 +3,14 @@
 #include <bsd/string.h>
 #include "template.h"
 
-int main3(void)
+int main(void)
 {
     char *source = "DE $cs: $bv $loc6, $hh:$mm:$ss, $tow, Ti$ti Te$te $hu $pr";
     char dest[512];
     telemetry_data data;
 
     data.battery_voltage_millivolts = 3247;
-    data.internal_temperature_celsius_100 = 27 * 100;
+    data.internal_temperature_celsius_100 = -7 * 100;
     data.temperature_celsius_100 = 24 * 100;
     data.humidity_percentage_100 = 68 * 100;
     data.pressure_mbar_100 = 1023 * 100;
@@ -24,4 +24,6 @@ int main3(void)
     template_replace(dest, sizeof(dest), source, &data);
 
     printf("%s\n", dest);
+
+    printf("%03d\n", data.internal_temperature_celsius_100 / 100);
 }