Reliability fixes for wired comms

components/dataLink/DataLinkFrames.cpp

@@ -151,7 +151,14 @@ esp_err_t DataLinkManager::complete_fragment(uint16_t board_id, uint16_t sequenc
     if (metadata.num_fragments_rx != metadata.fragments.size()){
         return ESP_ERR_INVALID_STATE;
     }
-    uint16_t total_data_len = metadata.num_fragments_rx * MAX_GENERIC_DATA_LEN; //max data size with n fragments
+    // Compute the exact total size from actual fragment data lengths, not the
+    // theoretical maximum (num_fragments * MAX_GENERIC_DATA_LEN). The last fragment
+    // is almost always shorter, so over-allocating would leave garbage bytes at the
+    // end that consumers reading combined_data->size() would see.
+    uint16_t total_data_len = 0;
+    for (size_t i = 0; i < metadata.num_fragments_rx; i++){
+        total_data_len += metadata.fragments[i].data_len;
+    }
     xSemaphoreGive(rx_fragment_mutex[channel]);
 
     auto combined_data = std::make_unique<std::vector<uint8_t>>();
@@ -181,6 +188,7 @@ esp_err_t DataLinkManager::complete_fragment(uint16_t board_id, uint16_t sequenc
         memcpy(&combined_data->data()[prev_index], metadata.fragments[i].data, metadata.fragments[i].data_len);
         prev_index += metadata.fragments[i].data_len;
     }
+    combined_data->resize(prev_index); // ensure vector size == actual data (no garbage tail bytes)
 
     xSemaphoreGive(rx_fragment_mutex[channel]);
 

components/dataLink/DataLinkRIP.cpp

@@ -175,9 +175,10 @@ esp_err_t DataLinkManager::rip_find_entry(uint8_t board_id, RIPRow** entry, bool
 }
 
 /**
- * @brief Returns the associated RIP Table row by row number. Information returned is read only.
+ * @brief Returns a snapshot of the RIP table row by row number. Information returned is a safe copy taken under the lock.
  *
- * @param entry
+ * @param entry  Pointer to a caller-owned RIPRow that will be filled with a snapshot of the table row.
+ *               The caller must NOT hold or release the internal row semaphore; it is managed here.
  * @param row_num
  * @return esp_err_t
  */
@@ -207,7 +208,12 @@ esp_err_t DataLinkManager::rip_get_row(RIPRow** entry, uint8_t row_num){
         }
     }
 
-    *entry = &rip_table[row_num];
+    static RIPRow row_snapshots[RIP_MAX_ROUTES];
+    row_snapshots[row_num].info    = rip_table[row_num].info;
+    row_snapshots[row_num].channel = rip_table[row_num].channel;
+    row_snapshots[row_num].ttl     = rip_table[row_num].ttl;
+    row_snapshots[row_num].valid   = rip_table[row_num].valid;
+    *entry = &row_snapshots[row_num];
 
     xSemaphoreGive(rip_table[row_num].row_sem);
 

components/rmt/RMTManager.cpp

@@ -30,9 +30,6 @@ esp_err_t RMTManager::init_tx_channel(){
     esp_err_t res_tx = ESP_FAIL;
     memory_to_free = xQueueCreate(15, sizeof(uint8_t*));
 
-    xTaskCreate(RMTManager::freeMemory, "RIPFreeMem", 4096, static_cast<void*>(memory_to_free), 5, NULL);
-    memory_to_free = xQueueCreate(15, sizeof(uint8_t*));
-
     xTaskCreate(RMTManager::freeMemory, "RIPFreeMem", 4096, static_cast<void*>(memory_to_free), 5, NULL);
 
     for (uint8_t i = 0; i < num_channels; i++){
@@ -414,7 +411,10 @@ esp_err_t RMTManager::send(uint8_t* data, size_t size, rmt_transmit_config_t* co
     esp_err_t res = rmt_transmit(this->channels[channel_num].tx_rmt_handle, this->channels[channel_num].encoder, new_data_to_send_buf.data, new_data_to_send_buf.length, config);
 
     if (res != ESP_OK){
-        // printf("Failed to send %s\n", data);
+        // rmt_transmit() failed: pull our item back out of the queue so the
+        // TX-done callback won't see it, then free the memory exactly once.
+        TxBuffer discarded = {};
+        xQueueReceive(channels[channel_num].tx_queue, &discarded, 0);
         vPortFree((void*)new_data_to_send_buf.data);
         ESP_LOGE(DEBUG_TAG, "Failed to send %s", data);
         return ESP_FAIL;
@@ -593,7 +593,7 @@ esp_err_t RMTManager::receive(uint8_t* recv_buf, size_t size, size_t* output_siz
     //     printf("duration0 %d level0 %d duration1 %d level1 %d\n", rx_data.received_symbols[i].duration0, rx_data.received_symbols[i].level0, rx_data.received_symbols[i].duration1, rx_data.received_symbols[i].level1);
     // }
 
-    int num = this->decode_symbols(rx_data.received_symbols, rx_data.num_symbols, channels[channel_num].decoded_recv_symbols, sizeof(channels[channel_num].decoded_recv_symbols));
+    int num = this->decode_symbols(rx_data.received_symbols, rx_data.num_symbols, channels[channel_num].decoded_recv_symbols, RECEIVE_BUFFER_SIZE);
     if (num < 0){
         return ESP_FAIL;
     }

main/control/DCMotorActuator.cpp

@@ -62,8 +62,10 @@ DCMotorActuator::DCMotorActuator() {
     this->m_integral = 0;
     this->m_last_error = 0;
 
-    xTaskCreate(reinterpret_cast<TaskFunction_t>(pid_task), "pid_task", 3072, this, 1,
+    // Pin the PID task to Core 1 so it doesn't compete with the RMT driver,
-                &this->m_pid_task);
+    // which runs its ISR and internal tasks on Core 0.
+    xTaskCreatePinnedToCore(reinterpret_cast<TaskFunction_t>(pid_task), "pid_task", 3072, this, 1,
+                            &this->m_pid_task, 1);
 }
 
 DCMotorActuator::~DCMotorActuator() {