add reliable BLE telemetry transport

main/trikke_ble_protocol.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define TRIKKE_BLE_FRAGMENT_HEADER_SIZE 8
+#define TRIKKE_BLE_ACK_SIZE             8
+
+// BLE data notifications carry a little-endian packet sequence, byte offset,
+// total TRK1 frame size, then the frame bytes at that offset. The unchanged
+// TRK1 CRC remains the end-to-end integrity check after reassembly.
+size_t trikke_ble_encode_fragment(
+    uint8_t *output,
+    size_t output_size,
+    const uint8_t *packet,
+    size_t packet_size,
+    size_t packet_offset,
+    size_t att_payload_capacity);
+
+// An application acknowledgement is ASCII "ACK1" followed by the exact
+// little-endian TRK1 packet sequence that the receiver persisted.
+bool trikke_ble_decode_ack(
+    const uint8_t *ack,
+    size_t ack_size,
+    uint32_t *packet_sequence);
+
+#ifdef __cplusplus
+}
+#endif