pybricks/bluetooth: Add bt classic inquiry scans.

bricks/_common/qstrdefs.h

@@ -15,6 +15,10 @@ Q(pybricks.ev3devices)
 Q(pybricks.experimental)
 #endif
 
+#if PYBRICKS_PY_COMMON_BTC
+Q(pybricks.experimental.btc)
+#endif
+
 #if MICROPY_PY_BUILTINS_FLOAT // backwards compatibility with Pybricks V3.2, maps to pybricks.tools
 Q(pybricks.geometry)
 #endif

bricks/_common/sources.mk

@@ -33,6 +33,7 @@ PYBRICKS_PYBRICKS_SRC_C = $(addprefix pybricks/,\
 	ev3devices/pb_type_ev3devices_infraredsensor.c \
 	ev3devices/pb_type_ev3devices_touchsensor.c \
 	ev3devices/pb_type_ev3devices_ultrasonicsensor.c \
+	experimental/pb_module_btc.c \
 	experimental/pb_module_experimental.c \
 	hubs/pb_module_hubs.c \
 	hubs/pb_type_buildhat.c \
@@ -116,6 +117,7 @@ PBIO_SRC_C = $(addprefix lib/pbio/,\
 	drv/bluetooth/bluetooth.c \
 	drv/bluetooth/bluetooth_btstack_stm32_hal.c \
 	drv/bluetooth/bluetooth_btstack.c \
+	drv/bluetooth/bluetooth_btstack_classic.c \
 	drv/bluetooth/bluetooth_btstack_ev3.c \
 	drv/bluetooth/bluetooth_simulation.c \
 	drv/bluetooth/bluetooth_stm32_bluenrg.c \

bricks/ev3/mpconfigport.h

@@ -16,6 +16,7 @@
 // Pybricks modules
 #define PYBRICKS_PY_COMMON                      (1)
 #define PYBRICKS_PY_COMMON_BLE                  (0)
+#define PYBRICKS_PY_COMMON_BTC                  (1)
 #define PYBRICKS_PY_COMMON_CHARGER              (0)
 #define PYBRICKS_PY_COMMON_COLOR_LIGHT          (1)
 #define PYBRICKS_PY_COMMON_CONTROL              (1)

lib/pbio/drv/bluetooth/bluetooth_btstack.c

@@ -23,6 +23,7 @@
 
 #include "bluetooth.h"
 #include "bluetooth_btstack.h"
+#include "bluetooth_btstack_classic.h"
 
 #if PBDRV_CONFIG_BLUETOOTH_BTSTACK_LE
 #include "genhdr/pybricks_service.h"
@@ -1181,6 +1182,10 @@ void pbdrv_bluetooth_init_hci(void) {
     nordic_spp_service_server_init(nordic_spp_packet_handler);
     #endif // PBDRV_CONFIG_BLUETOOTH_BTSTACK_LE
 
+    #if PBDRV_CONFIG_BLUETOOTH_CLASSIC
+    pbdrv_bluetooth_classic_init();
+    #endif
+
     bluetooth_thread_err = PBIO_ERROR_AGAIN;
     bluetooth_thread_state = 0;
     pbio_os_process_start(&pbdrv_bluetooth_hci_process, pbdrv_bluetooth_hci_process_thread, NULL);

lib/pbio/drv/bluetooth/bluetooth_btstack_classic.c

@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2025 The Pybricks Authors
+
+// This file defines the functions required to implement Pybricks' Bluetooth
+// classic functionality using BTStack.
+
+#include <pbdrv/config.h>
+
+#if PBDRV_CONFIG_BLUETOOTH_BTSTACK_CLASSIC
+
+#include <pbdrv/bluetooth.h>
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include <btstack.h>
+
+#include <pbdrv/bluetooth.h>
+
+static int32_t pending_inquiry_response_count;
+static int32_t pending_inquiry_response_limit;
+static void *pending_inquiry_result_handler_context;
+static pbdrv_bluetooth_inquiry_result_handler_t pending_inquiry_result_handler;
+
+static void handle_hci_event_packet(uint8_t *packet, uint16_t size);
+
+void pbdrv_bluetooth_classic_handle_packet(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
+    switch (packet_type) {
+        case HCI_EVENT_PACKET:
+            handle_hci_event_packet(packet, size);
+    }
+}
+
+static void handle_hci_event_packet(uint8_t *packet, uint16_t size) {
+    switch (hci_event_packet_get_type(packet)) {
+        case GAP_EVENT_INQUIRY_RESULT: {
+            if (!pending_inquiry_result_handler) {
+                return;
+            }
+            pbdrv_bluetooth_inquiry_result_t result;
+            gap_event_inquiry_result_get_bd_addr(packet, result.bdaddr);
+            if (gap_event_inquiry_result_get_rssi_available(packet)) {
+                result.rssi = gap_event_inquiry_result_get_rssi(packet);
+            }
+            if (gap_event_inquiry_result_get_name_available(packet)) {
+                const uint8_t *name = gap_event_inquiry_result_get_name(packet);
+                const size_t name_len = gap_event_inquiry_result_get_name_len(packet);
+                snprintf(result.name, sizeof(result.name), "%.*s", (int)name_len, name);
+            }
+            result.class_of_device = gap_event_inquiry_result_get_class_of_device(packet);
+            pending_inquiry_result_handler(pending_inquiry_result_handler_context, &result);
+            if (pending_inquiry_response_limit > 0) {
+                pending_inquiry_response_count++;
+                if (pending_inquiry_response_count >= pending_inquiry_response_limit) {
+                    gap_inquiry_stop();
+                }
+            }
+            break;
+        }
+        case GAP_EVENT_INQUIRY_COMPLETE: {
+            if (pending_inquiry_result_handler) {
+                pending_inquiry_result_handler = NULL;
+                pending_inquiry_result_handler_context = NULL;
+                pbio_os_request_poll();
+            }
+            break;
+        }
+        default:
+            break;
+    }
+}
+
+void pbdrv_bluetooth_classic_init() {
+    static btstack_packet_callback_registration_t hci_event_handler_registration;
+    hci_event_handler_registration.callback = pbdrv_bluetooth_classic_handle_packet;
+    hci_add_event_handler(&hci_event_handler_registration);
+}
+
+pbio_error_t pbdrv_bluetooth_inquiry_scan(
+    pbio_os_state_t *state,
+    int32_t max_responses,
+    int32_t timeout,
+    void *context,
+    pbdrv_bluetooth_inquiry_result_handler_t result_handler) {
+    PBIO_OS_ASYNC_BEGIN(state);
+    if (pending_inquiry_result_handler) {
+        return PBIO_ERROR_BUSY;
+    }
+    PBIO_OS_AWAIT_UNTIL(state, hci_get_state() == HCI_STATE_WORKING);
+    pending_inquiry_response_count = 0;
+    pending_inquiry_response_limit = max_responses;
+    pending_inquiry_result_handler = result_handler;
+    pending_inquiry_result_handler_context = context;
+    gap_inquiry_start(timeout);
+
+    PBIO_OS_AWAIT_UNTIL(state, !pending_inquiry_result_handler);
+    PBIO_OS_ASYNC_END(PBIO_SUCCESS);
+}
+
+#endif // PBDRV_CONFIG_BLUETOOTH_BTSTACK_CLASSIC

lib/pbio/drv/bluetooth/bluetooth_btstack_classic.h

@@ -0,0 +1,13 @@
+#ifndef PBDRV_BLUETOOTH_BLUETOOTH_BTSTACK_CLASSIC_H
+#define PBDRV_BLUETOOTH_BLUETOOTH_BTSTACK_CLASSIC_H
+#include <pbdrvconfig.h>
+
+#if PBDRV_CONFIG_BLUETOOTH_CLASSIC
+
+#include <stdint.h>
+
+void pbdrv_bluetooth_classic_init();
+
+#endif // PBDRV_CONFIG_BLUETOOTH_CLASSIC
+
+#endif  // PBDRV_BLUETOOTH_BLUETOOTH_BTSTACK_CLASSIC_H

lib/pbio/include/pbdrv/bluetooth.h

@@ -607,9 +607,50 @@ static inline pbio_error_t pbdrv_bluetooth_close_user_tasks(pbio_os_state_t *sta
     return PBIO_SUCCESS;
 }
 
-
 #endif // PBDRV_CONFIG_BLUETOOTH
 
+#if PBDRV_CONFIG_BLUETOOTH_CLASSIC
+
+// A single result from an inquiry scan.
+typedef struct {
+    uint8_t bdaddr[6];
+    int8_t rssi;
+    char name[249];
+    uint32_t class_of_device;
+} pbdrv_bluetooth_inquiry_result_t;
+
+// Callback for handling inquiry results.
+typedef void (*pbdrv_bluetooth_inquiry_result_handler_t)(void *context, const pbdrv_bluetooth_inquiry_result_t *result);
+
+/**
+ * Runs a bluetooth inquiry scan. Only one such scan can be active at a time.
+ *
+ * @param [in] state           Protothread state.
+ * @param [in] max_responses   Maximum number of responses to report. Use -1 for unlimited.
+ * @param [in] timeout         Timeout in units of 1.28 seconds. Values less than one will be coerced to one.
+ * @param [in] context         Context pointer to be passed to the result handler.
+ * @param [in] result_handler  Callback that will be called for each inquiry result.
+ */
+pbio_error_t pbdrv_bluetooth_inquiry_scan(
+    pbio_os_state_t *state,
+    int32_t max_responses,
+    int32_t timeout,
+    void *context,
+    pbdrv_bluetooth_inquiry_result_handler_t result_handler);
+
+#else // PBDRV_CONFIG_BLUETOOTH_CLASSIC
+
+static inline pbio_error_t pbdrv_bluetooth_inquiry_scan(
+    pbio_os_state_t *state,
+    int32_t max_responses,
+    int32_t timeout,
+    void *context,
+    void *result_handler) {
+    return PBIO_ERROR_NOT_SUPPORTED;
+}
+
+#endif // PBDRV_CONFIG_BLUETOOTH_CLASSIC
+
 #endif // _PBDRV_BLUETOOTH_H_
 
 /** @} */

lib/pbio/platform/ev3/pbdrvconfig.h

@@ -43,6 +43,7 @@
 #define PBDRV_CONFIG_I2C_EV3                        (1)
 
 #define PBDRV_CONFIG_BLUETOOTH                      (1)
+#define PBDRV_CONFIG_BLUETOOTH_CLASSIC              (1)
 #define PBDRV_CONFIG_BLUETOOTH_MAX_MTU_SIZE         515
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK              (1)
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK_CLASSIC      (1)