FHSS: Implemented TX slot calculation

Author: Jarkko Paso

source/Service_Libs/fhss/fhss_ws.c

@@ -309,7 +309,29 @@ static bool fhss_check_bad_channel(fhss_structure_t *fhss_structure, uint8_t han
 
 static bool fhss_ws_check_tx_allowed(fhss_structure_t *fhss_structure)
 {
-    return true;
+    // Ignore TX/RX slots
+    if (fhss_structure->own_hop == 0xff) {
+        return true;
+    }
+    // Currently on broadcast channel
+    if (fhss_structure->ws->is_on_bc_channel == true) {
+        return true;
+    }
+    uint32_t slot_len_ms = (fhss_structure->ws->fhss_configuration.fhss_broadcast_interval - fhss_structure->ws->fhss_configuration.fhss_bc_dwell_interval) / (WS_NUMBER_OF_TX_SLOTS * 2);
+    uint32_t remaining_time_ms = fhss_structure->platform_functions.fhss_get_remaining_slots(fhss_broadcast_handler, fhss_structure->fhss_api) / 1000;
+    uint32_t tx_slot_begin = (fhss_structure->ws->fhss_configuration.fhss_broadcast_interval - fhss_structure->ws->fhss_configuration.fhss_bc_dwell_interval) - (slot_len_ms * (fhss_structure->own_hop & 1));
+    uint32_t rx_slot_begin = tx_slot_begin - slot_len_ms;
+    uint8_t n_o_tx_slots = WS_NUMBER_OF_TX_SLOTS;
+
+    while (n_o_tx_slots--) {
+        if ((remaining_time_ms <= tx_slot_begin) && (remaining_time_ms > rx_slot_begin)) {
+            return true;
+        }
+        tx_slot_begin -= (2*slot_len_ms);
+        rx_slot_begin = tx_slot_begin - slot_len_ms;
+    }
+
+    return false;
 }
 
 static bool fhss_ws_check_tx_conditions_callback(const fhss_api_t *api, bool is_broadcast_addr, uint8_t handle, int frame_type, uint16_t frame_length, uint8_t phy_header_length, uint8_t phy_tail_length)

source/Service_Libs/fhss/fhss_ws.h

@@ -21,6 +21,8 @@
  * At least 4 channel retries must be used: (Initial channel + WS_NUMBER_OF_CHANNEL_RETRIES) * MAC attempts = (1+4)*4=20 attempts
  */
 #define WS_NUMBER_OF_CHANNEL_RETRIES    4
+//TODO: Make this configurable
+#define WS_NUMBER_OF_TX_SLOTS           2
 typedef struct fhss_ws fhss_ws_t;
 
 struct fhss_ws