pbio/broadcast: update header for compatability

In the v10.3.0 release of the MINDSTORMS Robot Inventor app the advertisement data is updated to include the lenght and correct company ID.
This commit updates the advertisement data structure used by pybricks.broadcast to comply with the MINDSTORMS Robot Inventor app.

lib/pbio/include/pbio/broadcast.h

@@ -11,7 +11,7 @@
 
 #if PBIO_CONFIG_BROADCAST_NUM_SIGNALS != 0
 
-#define PBIO_BROADCAST_MAX_PAYLOAD_SIZE (23)
+#define PBIO_BROADCAST_MAX_PAYLOAD_SIZE (22)
 
 void pbio_broadcast_parse_advertising_data(const uint8_t *data, uint8_t size);
 

lib/pbio/src/broadcast.c

@@ -18,22 +18,22 @@
 static struct {
     // Message data
     pbdrv_bluetooth_value_t value;
-    uint8_t header[3];
+    uint8_t length;
+    uint8_t AD_type;
+    uint16_t company_id;
     uint8_t index;
     uint32_t hash;
     char payload[PBIO_BROADCAST_MAX_PAYLOAD_SIZE];
     // Transmission info
     uint32_t timestamp;
     bool advertising_now;
 } __attribute__((packed)) transmit_signal = {
-    // Header for compatibility with official LEGO MINDSTORMS App:
-    // 0xFF for manufacturer data and 0x0397 for company ID.
-    .header = {255, 3, 151},
+    .AD_type = 0xff, // manufacturer data
+    .company_id = LWP3_LEGO_COMPANY_ID, // for compatibility with official LEGO MINDSTORMS App
     .advertising_now = false,
 };
 
-#define PBIO_BROADCAST_META_SIZE (8)
-#define PBIO_BROADCAST_MAX_PAYLOAD_SIZE (23)
+#define PBIO_BROADCAST_META_SIZE (9)
 #define PBIO_BROADCAST_DELAY_REPEAT_MS (100)
 
 PROCESS(pbio_broadcast_process, "broadcast");
@@ -133,6 +133,7 @@ void pbio_broadcast_transmit(uint32_t hash, const uint8_t *payload, uint8_t size
     }
 
     // Copy the payload.
+    transmit_signal.length = size - 1;
     transmit_signal.timestamp = time_now;
     transmit_signal.value.size = size + PBIO_BROADCAST_META_SIZE;
     memcpy(transmit_signal.payload, payload, size);
@@ -152,7 +153,8 @@ void pbio_broadcast_parse_advertising_data(const uint8_t *data, uint8_t size) {
     }
 
     // We only process data with the right header
-    if (memcmp(data, &transmit_signal.header[0], 3)) {
+    if ((data[0] != size - 1) && data[1] != transmit_signal.AD_type &&
+        memcmp(&data[2], &transmit_signal.company_id, 2)) {
         return;
     }
 
@@ -161,13 +163,13 @@ void pbio_broadcast_parse_advertising_data(const uint8_t *data, uint8_t size) {
         pbio_broadcast_received_t *signal = &received_signals[i];
 
         // If received does not match registered hash, skip it.
-        if (pbio_get_uint32_le(&data[4]) != signal->hash) {
+        if (pbio_get_uint32_le(&data[5]) != signal->hash) {
             continue;
         }
 
         // Get time and idex for incoming signal.
         uint32_t time_now = pbdrv_clock_get_ms();
-        uint8_t index_now = data[3];
+        uint8_t index_now = data[4];
 
         // For very quick updates, we should skip updating if new index is older.
         if (time_now - signal->timestamp < PBIO_BROADCAST_DELAY_REPEAT_MS && index_now - signal->index > 128) {