Add initial gps board integration

firmware/CMakeLists.txt

@@ -35,6 +35,9 @@ set(FALCON_PROTOS_DIR ${CMAKE_CURRENT_LIST_DIR}/../../modules/falcon-protos)
 zephyr_nanopb_sources(app ${FALCON_PROTOS_DIR}/HelloWorldPacket.proto)
 zephyr_nanopb_sources(app ${FALCON_PROTOS_DIR}/TelemetryPacket.proto)
 
+# LwGPS NMEA parser library
+set(LWGPS_DIR ${CMAKE_CURRENT_LIST_DIR}/../../modules/lwgps)
+
 target_sources(app PRIVATE
   src/main.c
   src/data.c
@@ -51,11 +54,15 @@ target_sources(app PRIVATE
   src/state_machine/states/landed.c
   src/pyro/pyro_thread.c
   src/radio/radio_thread.c
+  src/gps/gps_thread.c
+  ${LWGPS_DIR}/lwgps/src/lwgps/lwgps.c
 )
 
 target_include_directories(app PRIVATE
   src
   src/state_machine
+  src/gps
+  ${LWGPS_DIR}/lwgps/src/include
 )
 
 if(DEFINED DATA_FILE)

firmware/src/data.c

@@ -9,12 +9,14 @@ struct imu_data g_imu_data;
 struct baro_data g_baro_data;
 struct state_data g_state_data;
 struct pyro_data g_pyro_data;
+struct gps_data g_gps_data;
 
 // Mutexes for thread safety
 K_MUTEX_DEFINE(imu_mutex);
 K_MUTEX_DEFINE(baro_mutex);
 K_MUTEX_DEFINE(state_mutex);
 K_MUTEX_DEFINE(pyro_data_mutex);
+K_MUTEX_DEFINE(gps_mutex);
 
 // Setter functions
 void set_imu_data(const struct imu_data *src)
@@ -106,3 +108,17 @@ void get_pyro_data(struct pyro_data *dst)
     *dst = g_pyro_data;
     k_mutex_unlock(&pyro_data_mutex);
 }
+
+void set_gps_data(const struct gps_data *src)
+{
+    k_mutex_lock(&gps_mutex, K_FOREVER);
+    g_gps_data = *src;
+    k_mutex_unlock(&gps_mutex);
+}
+
+void get_gps_data(struct gps_data *dst)
+{
+    k_mutex_lock(&gps_mutex, K_FOREVER);
+    *dst = g_gps_data;
+    k_mutex_unlock(&gps_mutex);
+}

firmware/src/data.h

@@ -66,11 +66,22 @@ struct pyro_data {
     bool main_fire_requested;
 };
 
+struct gps_data {
+    float latitude;   // Degrees
+    float longitude;  // Degrees
+    float altitude;   // Altitude in meters
+    float speed;      // Speed in knots
+    uint8_t sats;     // Satellites in use
+    uint8_t fix;      // Fix quality
+    int64_t timestamp;
+};
+
 // Global instances
 extern struct imu_data g_imu_data;
 extern struct baro_data g_baro_data;
 extern struct state_data g_state_data;
 extern struct pyro_data g_pyro_data;
+extern struct gps_data g_gps_data;
 
 // Getters and setters
 void set_imu_data(const struct imu_data *src);
@@ -85,4 +96,7 @@ void get_state_data(struct state_data *dst);
 void set_pyro_data(const struct pyro_data *src);
 void get_pyro_data(struct pyro_data *dst);
 
+void set_gps_data(const struct gps_data *src);
+void get_gps_data(struct gps_data *dst);
+
 #endif

firmware/src/gps/gps_thread.c

@@ -0,0 +1,144 @@
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/spi.h>
+#include <zephyr/logging/log.h>
+#include <lwgps/lwgps.h>
+#include <string.h>
+#include "data.h"
+
+LOG_MODULE_REGISTER(gps_thread, LOG_LEVEL_INF);
+
+#define GPS_THREAD_STACK_SIZE 2048
+#define GPS_THREAD_PRIORITY 6
+#define GPS_THREAD_PERIOD_MS 1000
+
+/* SPI protocol constants (ulysses-gnss-radio spec) */
+#define SPI_CMD_GPS_RX    0x05
+#define SPI_DUMMY_SIZE    4
+#define SPI_HEADER_SIZE   (1 + SPI_DUMMY_SIZE) /* 5: cmd + dummy bytes */
+#define GPS_PAYLOAD_SIZE  87   /* Max NMEA sentence length */
+
+/* Total SPI transaction: [CMD:1][DUMMY:4][PAYLOAD:87] = 92 bytes */
+#define SPI_GPS_RX_SIZE   (SPI_HEADER_SIZE + GPS_PAYLOAD_SIZE) /* 92 */
+
+K_THREAD_STACK_DEFINE(gps_stack, GPS_THREAD_STACK_SIZE);
+static struct k_thread gps_thread;
+
+static const struct spi_dt_spec gps_spi =
+	SPI_DT_SPEC_GET(DT_ALIAS(radio0),
+			SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB | SPI_WORD_SET(8));
+
+static lwgps_t gps;
+
+static int gps_spi_read(uint8_t *payload_out)
+{
+	uint8_t tx_buf[SPI_GPS_RX_SIZE] = {0};
+	uint8_t rx_buf[SPI_GPS_RX_SIZE] = {0};
+
+	tx_buf[0] = SPI_CMD_GPS_RX;
+	/* bytes 1-4 are dummy, rest is zero (master clocks out zeros) */
+
+	const struct spi_buf spi_tx = {
+		.buf = tx_buf,
+		.len = sizeof(tx_buf),
+	};
+	const struct spi_buf_set tx_set = {
+		.buffers = &spi_tx,
+		.count = 1,
+	};
+
+	const struct spi_buf spi_rx = {
+		.buf = rx_buf,
+		.len = sizeof(rx_buf),
+	};
+	const struct spi_buf_set rx_set = {
+		.buffers = &spi_rx,
+		.count = 1,
+	};
+
+	int ret = spi_transceive_dt(&gps_spi, &tx_set, &rx_set);
+	if (ret < 0) {
+		return ret;
+	}
+
+	/* Payload starts after header (cmd + dummy bytes) */
+	memcpy(payload_out, &rx_buf[SPI_HEADER_SIZE], GPS_PAYLOAD_SIZE);
+
+	return 0;
+}
+
+static void gps_thread_fn(void *p1, void *p2, void *p3)
+{
+	if (!spi_is_ready_dt(&gps_spi)) {
+		LOG_ERR("GPS SPI device not ready");
+		return;
+	}
+	LOG_INF("GPS SPI device ready");
+
+	lwgps_init(&gps);
+
+	while (1) {
+		uint8_t payload[GPS_PAYLOAD_SIZE];
+
+		int ret = gps_spi_read(payload);
+		if (ret < 0) {
+			LOG_ERR("GPS SPI read failed: %d", ret);
+			k_sleep(K_MSEC(GPS_THREAD_PERIOD_MS));
+			continue;
+		}
+
+		/* Check for empty payload (all zero bytes from SPI) */
+		bool payload_empty = true;
+		for (size_t i = 0; i < GPS_PAYLOAD_SIZE; i++) {
+			if (payload[i] != 0) {
+				payload_empty = false;
+				break;
+			}
+		}
+		if (payload_empty) {
+			LOG_WRN("GPS SPI payload is empty (all zeros)");
+			k_sleep(K_MSEC(GPS_THREAD_PERIOD_MS));
+			continue;
+		}
+
+		/* Null-terminate and find actual sentence length */
+		char nmea[GPS_PAYLOAD_SIZE + 1];
+		memcpy(nmea, payload, GPS_PAYLOAD_SIZE);
+		nmea[GPS_PAYLOAD_SIZE] = '\0';
+		size_t len = strlen(nmea);
+
+		if (len == 0 || nmea[0] != '$') {
+			k_sleep(K_MSEC(GPS_THREAD_PERIOD_MS));
+			continue;
+		}
+
+		lwgps_process(&gps, nmea, len);
+
+		struct gps_data gps_out = {
+			.latitude = gps.latitude,
+			.longitude = gps.longitude,
+			.altitude = gps.altitude,
+			.speed = gps.speed,
+			.sats = gps.sats_in_use,
+			.fix = gps.fix,
+			.timestamp = k_uptime_get(),
+		};
+		set_gps_data(&gps_out);
+
+		LOG_INF("NMEA: %s", nmea);
+		LOG_INF("GPS: lat=%.6f, lon=%.6f, alt=%.1f m, "
+			"sats=%u, fix=%u, speed=%.1f kn",
+			(double)gps.latitude, (double)gps.longitude,
+			(double)gps.altitude, gps.sats_in_use, gps.fix,
+			(double)gps.speed);
+
+		k_sleep(K_MSEC(GPS_THREAD_PERIOD_MS));
+	}
+}
+
+void start_gps_thread(void)
+{
+	k_thread_create(&gps_thread, gps_stack, K_THREAD_STACK_SIZEOF(gps_stack),
+			gps_thread_fn, NULL, NULL, NULL, GPS_THREAD_PRIORITY, 0, K_NO_WAIT);
+}

firmware/src/gps/gps_thread.h

@@ -0,0 +1,6 @@
+#ifndef GPS_THREAD_H
+#define GPS_THREAD_H
+
+void start_gps_thread(void);
+
+#endif

firmware/src/gps/lwgps_opts.h

@@ -0,0 +1,10 @@
+#ifndef LWGPS_OPTS_H
+#define LWGPS_OPTS_H
+
+/* Use float instead of double to save memory on Cortex-M4 */
+#define LWGPS_CFG_DOUBLE 0
+
+/* We don't need satellite detail descriptors */
+#define LWGPS_CFG_STATEMENT_GPGSV_SAT_DET 0
+
+#endif

firmware/src/log_format.h

@@ -11,6 +11,7 @@ struct log_frame {
     struct baro_data baro;
     struct state_data state;
     struct pyro_data pyro;
+    struct gps_data gps;
 };
 
 #endif

firmware/src/logger_thread.c

@@ -94,9 +94,10 @@ static int write_csv_header(void)
                          "Pyro_Status,Pyro_Timestamp(ms),"
                          "Drogue_Fired,Main_Fired,Drogue_Fail,Main_Fail,"
                          "Drogue_Cont_OK,Main_Cont_OK,Drogue_Fire_ACK,Main_Fire_ACK,"
-                         "Drogue_Fire_Requested,Main_Fire_Requested\n";
-
-#ifdef CONFIG_BOARD_NATIVE_SIM
+                         "Drogue_Fire_Requested,Main_Fire_Requested,"
+                         "GPS_Timestamp(ms),GPS_Lat(deg),GPS_Lon(deg),"
+                         "GPS_Alt(m),GPS_Speed(kn),GPS_Sats,GPS_Fix\n";
+    #ifdef CONFIG_BOARD_NATIVE_SIM
     size_t written = fwrite(header, 1, strlen(header), log_file_ptr);
     if (written != strlen(header)) {
         LOG_ERR("Failed to write header");
@@ -193,11 +194,12 @@ static int format_log_entry(const struct log_frame *frame, char *buffer, size_t
 {
     return snprintf(
         buffer, buffer_size,
-        "%lld,%lld,%.3f,%.3f,%.3f,%.3f,%.3f,%.3f,%lld,"
-        "%.3f,%.3f,%.3f,%.3f,%u,%d,"
-        "%.3f,%.3f,%.3f,%.3f,%u,%d,"
-        "%.3f,%.3f,%.3f,%.3f,%.3f,%d,%.3f,%lld,"
-        "%u,%lld,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d\n",
+        "%lld,%lld,%.3f,%.3f,%.3f,%.3f,%.3f,%.3f,%lld," // Log_Timestamp, IMU_Timestamp, Accel_X/Y/Z, Gyro_X/Y/Z, Baro_Timestamp
+        "%.3f,%.3f,%.3f,%.3f,%u,%d," // Baro0_Pressure, Baro0_Temperature, Baro0_Altitude, Baro0_NIS, Baro0_Faults, Baro0_Healthy
+        "%.3f,%.3f,%.3f,%.3f,%u,%d," // Baro1_Pressure, Baro1_Temperature, Baro1_Altitude, Baro1_NIS, Baro1_Faults, Baro1_Healthy
+        "%.3f,%.3f,%.3f,%.3f,%.3f,%d,%.3f,%lld," // KF_Altitude, KF_Altitude_AGL, KF_AltVar, KF_Velocity, KF_VelVar, State, State_Ground_Altitude, State_Timestamp
+        "%u,%lld,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d," // Pyro_Status, Pyro_Timestamp, Drogue_Fired, Main_Fired, Drogue_Fail, Main_Fail, Drogue_Cont_OK, Main_Cont_OK, Drogue_Fire_ACK, Main_Fire_ACK, Drogue_Fire_Requested, Main_Fire_Requested
+        "%lld,%.6f,%.6f,%.1f,%.1f,%u,%u\n", // GPS_Timestamp, GPS_Lat, GPS_Lon, GPS_Alt, GPS_Speed, GPS_Sats, GPS_Fix
         frame->log_timestamp,
         frame->imu.timestamp,
         (double)frame->imu.accel[0], (double)frame->imu.accel[1], (double)frame->imu.accel[2],
@@ -218,7 +220,12 @@ static int format_log_entry(const struct log_frame *frame, char *buffer, size_t
         frame->pyro.drogue_fail ? 1 : 0, frame->pyro.main_fail ? 1 : 0,
         frame->pyro.drogue_cont_ok ? 1 : 0, frame->pyro.main_cont_ok ? 1 : 0,
         frame->pyro.drogue_fire_ack ? 1 : 0, frame->pyro.main_fire_ack ? 1 : 0,
-        frame->pyro.drogue_fire_requested ? 1 : 0, frame->pyro.main_fire_requested ? 1 : 0);
+        frame->pyro.drogue_fire_requested ? 1 : 0, frame->pyro.main_fire_requested ? 1 : 0,
+        frame->gps.timestamp,
+        (double)frame->gps.latitude, (double)frame->gps.longitude,
+        (double)frame->gps.altitude, (double)frame->gps.speed,
+        (unsigned int)frame->gps.sats, (unsigned int)frame->gps.fix
+    );
 }
 
 static void write_log_frame_to_file(const struct log_frame *frame)
@@ -267,6 +274,7 @@ static void logger_thread_fn(void *p1, void *p2, void *p3)
         get_baro_data(&frame.baro);
         get_state_data(&frame.state);
         get_pyro_data(&frame.pyro);
+        get_gps_data(&frame.gps);
 
         write_log_frame_to_file(&frame);
 

firmware/src/main.c

@@ -9,6 +9,7 @@
 #include "state_machine/state_machine.h"
 #include "pyro/pyro_thread.h"
 #include "radio/radio_thread.h"
+#include "gps/gps_thread.h"
 #include "data.h"
 
 LOG_MODULE_REGISTER(falcon_main, LOG_LEVEL_INF);
@@ -24,6 +25,7 @@ int main(void)
     start_pyro_thread();
     start_state_machine_thread();
     start_radio_thread();
+    start_gps_thread();
 
     return 0;
 }

firmware/src/radio/radio_thread.c

@@ -81,10 +81,12 @@ static void radio_thread_fn(void *p1, void *p2, void *p3)
 		struct imu_data imu;
 		struct baro_data baro;
 		struct state_data state;
+		struct gps_data gps;
 
 		get_imu_data(&imu);
 		get_baro_data(&baro);
 		get_state_data(&state);
+		get_gps_data(&gps);
 
 		message.counter = counter;
 		message.timestamp_ms = (uint32_t)k_uptime_get();
@@ -105,6 +107,13 @@ static void radio_thread_fn(void *p1, void *p2, void *p3)
 
 		message.ground_altitude = state.ground_altitude;
 
+		message.gps_latitude = gps.latitude;
+		message.gps_longitude = gps.longitude;
+		message.gps_altitude = gps.altitude;
+		message.gps_speed = gps.speed;
+		message.gps_sats = gps.sats;
+		message.gps_fix = gps.fix;
+
 		pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
 		bool status = pb_encode(&stream, TelemetryPacket_fields, &message);
 		size_t message_length = stream.bytes_written;

west.yml

@@ -4,6 +4,8 @@ manifest:
       url-base: https://github.com/zephyrproject-rtos
     - name: ubc-rocket
       url-base: https://github.com/UBC-Rocket
+    - name: lwgps-remote
+      url-base: https://github.com/MaJerle
 
   projects:
     - name: zephyr
@@ -14,6 +16,10 @@ manifest:
       remote: ubc-rocket
       revision: main
       path: modules/falcon-protos
+    - name: lwgps
+      remote: lwgps-remote
+      revision: main
+      path: modules/lwgps
 
   self:
     path: app