Add temperature compensation matrix support

Add example temperature compensation to global_conf.json

2 files changed, 110 insertions, 0 deletions

diff --git a/lora_pkt_fwd/global_conf.json b/lora_pkt_fwd/global_conf.json
index 2d0948c..d73b50c 100644
--- a/lora_pkt_fwd/global_conf.json
+++ b/lora_pkt_fwd/global_conf.json
@@ -14,6 +14,11 @@
             "sx127x_rssi_offset": -4 /* dB */
         },
         "antenna_gain": 0, /* antenna gain, in dBi */
+        "temperature_comp": {
+            "enabled": false,
+            "values": [ [-20,-2], [-10,-1], [0,0], [0,0] ],
+            "current_temp_file": "/var/run/lora/current_temp"
+        },
         "radio_0": {
             "enable": true,
             "type": "SX1257",
diff --git a/lora_pkt_fwd/src/lora_pkt_fwd.c b/lora_pkt_fwd/src/lora_pkt_fwd.c
index 34996d4..7ced41e 100644
--- a/lora_pkt_fwd/src/lora_pkt_fwd.c
+++ b/lora_pkt_fwd/src/lora_pkt_fwd.c
@@ -294,6 +294,14 @@ static struct jit_queue_s jit_queue;
 /* Gateway specificities */
 static int8_t antenna_gain = 0;
 
+#define TEMP_ADJ_MAX 4
+#define DEFAULT_TEMP_COMP_FILE "/var/run/lora/current_temp"
+static int16_t temp_comp_table[TEMP_ADJ_MAX][2] = { 0 };
+static char temp_comp_file[64] = {0};
+static int16_t temp_comp_value = 0;
+static int16_t temp_comp_adj = 0;
+static bool temp_comp_enabled = false;
+
 /* TX capabilities */
 static struct lgw_tx_gain_lut_s txlut; /* TX gain table */
 static uint32_t tx_freq_min[LGW_RF_CHAIN_NB]; /* lowest frequency supported by TX chain */
@@ -330,6 +338,34 @@ void thread_spectralscan(void);
 /* -------------------------------------------------------------------------- */
 /* --- PRIVATE FUNCTIONS DEFINITION ----------------------------------------- */
 
+static void update_temp_comp_value() {
+    if (!temp_comp_enabled) {
+        return;
+    }
+    /* try to open file to read */
+    FILE *filePointer;
+    if (filePointer = fopen(temp_comp_file, "r")) {
+        int bufferLength = 4;
+        char buffer[bufferLength];
+
+        fgets(buffer, bufferLength, filePointer);
+        temp_comp_value = atoi(buffer);
+
+        int16_t adj_val = 0;
+
+        for (int i = 0; i < TEMP_ADJ_MAX; i++) {
+            if (temp_comp_table[i][0] <= temp_comp_value) {
+                adj_val = temp_comp_table[i][1];
+            }
+        }
+
+        temp_comp_adj = adj_val;
+
+        fclose(filePointer);
+    }
+
+}
+
 static enum lgw_sx127x_rxbw_e map_bandwidth(uint32_t bandwidth) {
     switch (bandwidth) {
         case 25:
@@ -475,6 +511,7 @@ static int parse_SX1301_configuration(const char * conf_file) {
     JSON_Value *root_val = NULL;
     JSON_Object *conf_obj = NULL;
     JSON_Object *conf_lbt_obj = NULL;
+    JSON_Object *conf_temp_comp_obj = NULL;
     JSON_Object *conf_lbtchan_obj = NULL;
     JSON_Value *val = NULL;
     JSON_Array *conf_array = NULL;
@@ -619,6 +656,61 @@ static int parse_SX1301_configuration(const char * conf_file) {
     }
     MSG("INFO: antenna_gain %d dBi\n", antenna_gain);
 
+    conf_temp_comp_obj = json_object_get_object(conf_obj, "temperature_comp"); /* fetch value (if possible) */
+    if (conf_temp_comp_obj == NULL) {
+        MSG("INFO: no configuration for Temperature Compensation\n");
+    } else {
+        val = json_object_get_value(conf_temp_comp_obj, "enable"); /* fetch value (if possible) */
+        if (json_value_get_type(val) == JSONBoolean) {
+            temp_comp_enabled = (bool)json_value_get_boolean(val);
+        } else {
+            temp_comp_enabled = false;
+        }
+
+        if (temp_comp_enabled) {
+            MSG("INFO: Temperature Compensation enabled\n");
+
+            /* Current temperature path (optional) */
+            str = json_object_get_string(conf_temp_comp_obj, "current_temp_file");
+            if (str != NULL) {
+                strncpy(temp_comp_file, str, sizeof(temp_comp_file)-1);
+                MSG("INFO: Current temperature file is configured to \"%s\"\n", temp_comp_file);
+            } else {
+                strncpy(temp_comp_file, DEFAULT_TEMP_COMP_FILE, sizeof(temp_comp_file)-1);
+            }
+
+            /* load temp adj table */
+            int adj_count = 0;
+            conf_array = json_object_get_array(conf_temp_comp_obj, "values");
+            if (conf_array != NULL) {
+                adj_count = json_array_get_count( conf_array );
+
+                JSON_Array *temp_values = NULL;
+                for (i = 0; i < (int)adj_count; i++) {
+                    /* Sanity check */
+                    if (i >= TEMP_ADJ_MAX)
+                    {
+                        MSG("ERROR: Temp adj %d not supported, skip it\n", i );
+                        break;
+                    }
+
+                    /* Get LBT channel configuration object from array */
+                    temp_values = json_array_get_array(conf_array, i);
+                    size_t cnt = json_array_get_count(temp_values);
+
+                    if (cnt == 2) {
+                        temp_comp_table[i][0] = (int16_t)json_array_get_number(temp_values, 0);
+                        temp_comp_table[i][1] = (int16_t)json_array_get_number(temp_values, 1);
+                    }
+                }
+            }
+
+            update_temp_comp_value();
+        } else {
+            MSG("INFO: Temperature Compensation disabled\n");
+        }
+    }
+
     /* set configuration for tx gains */
     memset(&txlut, 0, sizeof txlut); /* initialize configuration structure */
     for (i = 0; i < TX_GAIN_LUT_SIZE_MAX; i++) {
@@ -1752,6 +1844,8 @@ int main(int argc, char** argv)
             break;
 	    }
 
+        /* read the currrent temperature */
+
         pthread_mutex_unlock(&mx_concent);
         if (i != LGW_HAL_SUCCESS) {
             printf("# SX1301 time (PPS): unknown\n");
@@ -1759,6 +1853,12 @@ int main(int argc, char** argv)
             printf("# SX1301 time (PPS): %u %u\n", trig_tstamp, page);
         }
 
+        if (temp_comp_enabled) {
+            update_temp_comp_value();
+            printf("# Temperature:    %i C\n", temp_comp_value);
+            printf("# Temp TxPow Adj: %i dB\n", temp_comp_adj);
+        }
+
         jit_print_queue (&jit_queue, false, DEBUG_LOG);
         printf("### [GPS] ###\n");
         if (gps_enabled == true) {
@@ -2874,6 +2974,11 @@ void thread_down(void) {
                 }
             }
 
+            if (temp_comp_enabled) {
+                txpkt.rf_power += (int8_t)temp_comp_adj;
+                MSG("INFO: Tx power temp adjusted to %d\n", (int)txpkt.rf_power);
+            }
+
             /* Parse modulation (mandatory) */
             str = json_object_get_string(txpk_obj, "modu");
             if (str == NULL) {