Add BLE host transport selectable via DIP8 alongside UART.

Master can speak the same framed protobuf protocol over NimBLE or UART; goTool gains -ble, ble-rtt, and ble-stream timing checks for ESP-NOW coexistence.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/host_transport.c

@@ -0,0 +1,97 @@
+#include "host_transport.h"
+#include "cmd_handler.h"
+#include "esp_log.h"
+#include "uart.h"
+#include <stdlib.h>
+#include <string.h>
+
+static const char *TAG = "[HOST]";
+
+static host_tx_fn_t s_tx_fn;
+static QueueHandle_t s_cmd_queue;
+static uart_packet_t s_rx_packet = {.state = STATE_START};
+static TickType_t s_last_byte_ticks;
+static const TickType_t s_rx_timeout_ticks = pdMS_TO_TICKS(50);
+
+void host_transport_set_tx(host_tx_fn_t tx_fn) { s_tx_fn = tx_fn; }
+
+void host_transport_set_cmd_queue(QueueHandle_t cmd_queue) {
+  s_cmd_queue = cmd_queue;
+}
+
+QueueHandle_t host_transport_cmd_queue(void) { return s_cmd_queue; }
+
+bool host_enqueue_packet(const uint8_t *payload, uint8_t len) {
+  if (s_cmd_queue == NULL || payload == NULL || len == 0) {
+    return false;
+  }
+
+  generic_msg_t msg = {
+      .msg_id = payload[0],
+      .len = len > 1 ? (size_t)(len - 1) : 0,
+      .payload = NULL,
+  };
+
+  if (msg.len > 0) {
+    msg.payload = malloc(msg.len);
+    if (msg.payload == NULL) {
+      ESP_LOGE(TAG, "failed to allocate command payload");
+      return false;
+    }
+    memcpy(msg.payload, &payload[1], msg.len);
+  }
+
+  if (xQueueSend(s_cmd_queue, &msg, pdMS_TO_TICKS(500)) != pdPASS) {
+    free(msg.payload);
+    ESP_LOGW(TAG, "command queue full (cmd 0x%02x)", (unsigned)msg.msg_id);
+    return false;
+  }
+  return true;
+}
+
+esp_err_t host_send_framed(const uint8_t *payload, size_t len) {
+  if (payload == NULL || len == 0 || len > MAX_PAYLOAD_SIZE) {
+    return ESP_ERR_INVALID_ARG;
+  }
+  if (s_tx_fn == NULL) {
+    return ESP_ERR_INVALID_STATE;
+  }
+
+  uint8_t checksum = 0;
+  for (size_t i = 0; i < len; i++) {
+    checksum ^= payload[i];
+  }
+
+  uint8_t frame[4 + MAX_PAYLOAD_SIZE];
+  size_t pos = 0;
+  frame[pos++] = START_MARKER;
+  frame[pos++] = (uint8_t)len;
+  memcpy(&frame[pos], payload, len);
+  pos += len;
+  frame[pos++] = checksum;
+  frame[pos++] = STOP_MARKER;
+
+  return s_tx_fn(frame, pos);
+}
+
+void host_rx_bytes(const uint8_t *data, size_t len) {
+  if (data == NULL || len == 0) {
+    return;
+  }
+
+  TickType_t now = xTaskGetTickCount();
+  if (s_rx_packet.state != STATE_START &&
+      (now - s_last_byte_ticks) > s_rx_timeout_ticks) {
+    s_rx_packet.state = STATE_START;
+  }
+
+  for (size_t i = 0; i < len; i++) {
+    if (parse_uart_byte(data[i], &s_rx_packet)) {
+      ESP_LOGI(TAG, "received message cmd=0x%02x len=%u",
+               s_rx_packet.len > 0 ? s_rx_packet.payload[0] : 0,
+               (unsigned)s_rx_packet.len);
+      host_enqueue_packet(s_rx_packet.payload, s_rx_packet.len);
+    }
+  }
+  s_last_byte_ticks = now;
+}