Add Bluetooth examples

Co-authored-by: Peter Harper <77111776+peterharperuk@users.noreply.github.com>

pico_w/bt/standalone/server.c

@@ -0,0 +1,79 @@
+/**
+ * Copyright (c) 2023 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "btstack.h"
+#include "pico/cyw43_arch.h"
+#include "pico/btstack_cyw43.h"
+#include "hardware/adc.h"
+#include "pico/stdlib.h"
+
+#include "server_common.h"
+
+#define HEARTBEAT_PERIOD_MS 1000
+
+static btstack_timer_source_t heartbeat;
+static btstack_packet_callback_registration_t hci_event_callback_registration;
+
+static void heartbeat_handler(struct btstack_timer_source *ts) {
+    static uint32_t counter = 0;
+    counter++;
+
+    // Update the temp every 10s
+    if (counter % 10 == 0) {
+        poll_temp();
+        if (le_notification_enabled) {
+            att_server_request_can_send_now_event(con_handle);
+        }
+    }
+
+    // Invert the led
+    static int led_on = true;
+    led_on = !led_on;
+    cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, led_on);
+
+    // Restart timer
+    btstack_run_loop_set_timer(ts, HEARTBEAT_PERIOD_MS);
+    btstack_run_loop_add_timer(ts);
+}
+
+int main() {
+    stdio_init_all();
+
+    // initialize CYW43 driver architecture (will enable BT if/because CYW43_ENABLE_BLUETOOTH == 1)
+    if (cyw43_arch_init()) {
+        printf("failed to initialise cyw43_arch\n");
+        return -1;
+    }
+
+    // Initialise adc for the temp sensor
+    adc_init();
+    adc_select_input(ADC_CHANNEL_TEMPSENSOR);
+    adc_set_temp_sensor_enabled(true);
+
+    l2cap_init();
+    sm_init();
+
+    att_server_init(profile_data, att_read_callback, att_write_callback);    
+
+    // inform about BTstack state
+    hci_event_callback_registration.callback = &packet_handler;
+    hci_add_event_handler(&hci_event_callback_registration);
+
+    // register for ATT event
+    att_server_register_packet_handler(packet_handler);
+
+    // set one-shot btstack timer
+    heartbeat.process = &heartbeat_handler;
+    btstack_run_loop_set_timer(&heartbeat, HEARTBEAT_PERIOD_MS);
+    btstack_run_loop_add_timer(&heartbeat);
+
+    // turn on bluetooth!
+    hci_power_control(HCI_POWER_ON);
+
+    btstack_run_loop_execute();
+    return 0;
+}