BLE advertisement support for MicroPython

Adds BLE 4.x advertisement support to Micropython.

Still missing:

• Decision of what should happen when gap_advertise() is called while a connection is already open. Currently an open connection is closed in that case.

epicardium/ble/ble_adv.c

+#include "ble_api.h"
+#include "epicardium.h"
+#include "modules/log.h"
+#include "modules/config.h"
+
+#include "wsf_types.h"
+#include "util/bstream.h"
+#include "wsf_msg.h"
+#include "wsf_trace.h"
+#include "app_api.h"
+#include "app_db.h"
+#include "svc_ch.h"
+#include "profiles/gap_api.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#define DEFAULT_ADV_INTERVAL_US 500000
+
+/*! configurable parameters for advertising */
+static appAdvCfg_t bleAdvCfg = {
+	{ 0, 0 }, /*! Advertising durations in ms */
+	{ DEFAULT_ADV_INTERVAL_US / 625,
+	  0 } /*! Advertising intervals in 0.625 ms units */
+};
+
+static bool tainted;
+
+/**************************************************************************************************
+  Advertising Data
+**************************************************************************************************/
+
+/* clang-format off */
+/*! advertising data, discoverable mode */
+static const uint8_t bleAdvDataDisc[] = {
+	/*! flags */
+	2,                        /*! length */
+	DM_ADV_TYPE_FLAGS,        /*! AD type */
+	DM_FLAG_LE_LIMITED_DISC | /*! flags */
+	DM_FLAG_LE_BREDR_NOT_SUP,
+
+	3,
+	DM_ADV_TYPE_APPEARANCE,
+	UINT16_TO_BYTES(CH_APPEAR_WATCH),
+
+	/*! service UUID list */
+	17,
+	DM_ADV_TYPE_128_UUID_PART,
+	CARD10_UUID_SUFFIX,
+	0x0,
+	CARD10_UUID_PREFIX,
+
+	2,                    /*! length */
+	DM_ADV_TYPE_TX_POWER, /*! AD type */
+	0,                    /*! tx power */
+};
+
+/*! advertising data, discoverable mode with HID service*/
+static const uint8_t bleAdvDataDiscHID[] = {
+	/*! flags */
+	2,                        /*! length */
+	DM_ADV_TYPE_FLAGS,        /*! AD type */
+	DM_FLAG_LE_LIMITED_DISC | /*! flags */
+	DM_FLAG_LE_BREDR_NOT_SUP,
+
+	3,
+	DM_ADV_TYPE_APPEARANCE,
+	UINT16_TO_BYTES(CH_APPEAR_WATCH),
+
+	/*! service UUID list */
+	17,
+	DM_ADV_TYPE_128_UUID_PART,
+	CARD10_UUID_SUFFIX,
+	0x0,
+	CARD10_UUID_PREFIX,
+
+	3,                        /*! length */
+	DM_ADV_TYPE_16_UUID_PART, /*! AD type */
+	UINT16_TO_BYTES(ATT_UUID_HID_SERVICE)
+};
+
+/*! scan data, discoverable mode */
+uint8_t bleScanDataDisc[] = {
+	/*! device name */
+	14,                     /*! length */
+	DM_ADV_TYPE_LOCAL_NAME, /*! AD type */
+	'c','a','r','d','1','0','-','0','0','0','0','0','0',
+
+	3,                      /*! length */
+	DM_ADV_TYPE_16_SOLICIT, /*! AD type */
+	UINT16_TO_BYTES(ATT_UUID_CURRENT_TIME_SERVICE),
+};
+/* clang-format on */
+
+/*! advertising data, connectable mode */
+static const uint8_t bleAdvDataConn[] = {
+	/*! flags */
+	2,                 /*! length */
+	DM_ADV_TYPE_FLAGS, /*! AD type */
+	DM_FLAG_LE_BREDR_NOT_SUP,
+};
+
+static uint8_t advertising_mode        = APP_MODE_NONE;
+static uint8_t advertising_mode_target = APP_MODE_NONE;
+
+void ble_adv_proc_msg(bleMsg_t *pMsg)
+{
+	switch (pMsg->hdr.event) {
+	case DM_ADV_START_IND:
+		LOG_INFO(
+			"ble",
+			"Advertisement started %u %u",
+			advertising_mode,
+			advertising_mode_target
+		);
+		if (advertising_mode != advertising_mode_target ||
+		    advertising_mode_target == APP_MODE_NONE) {
+			AppAdvStop();
+		}
+		break;
+
+	case DM_ADV_STOP_IND:
+		LOG_INFO(
+			"ble",
+			"Advertisement stopped %u %u",
+			advertising_mode,
+			advertising_mode_target
+		);
+		if (advertising_mode != advertising_mode_target) {
+			advertising_mode = advertising_mode_target;
+			AppAdvStart(advertising_mode);
+		}
+		break;
+	case DM_CONN_CLOSE_IND:
+		/* Stack overwrites advertising mode after connection close.
+		 * Force our desired mode.
+		 */
+		advertising_mode = APP_MODE_NONE;
+		AppAdvStop();
+		break;
+	};
+}
+
+void ble_adv_init(void)
+{
+	char buf[32];
+	char a, b, c, d, e, f, K;
+
+	/* clang-format off */
+	int result = epic_config_get_string("ble_mac", buf, sizeof(buf));
+	if (result == 0) {
+		if (sscanf(buf,
+			   "%c%c:%c%c:%c%c:%c%c:%c%c:%c%c",
+			   &K, &K, &K, &K, &K, &K,
+			   &a, &b, &c, &d, &e, &f) == 12) {
+			bleScanDataDisc[9]  = a;
+			bleScanDataDisc[10] = b;
+			bleScanDataDisc[11] = c;
+			bleScanDataDisc[12] = d;
+			bleScanDataDisc[13] = e;
+			bleScanDataDisc[14] = f;
+		}
+	}
+	/* clang-format on */
+
+	pAppAdvCfg = (appAdvCfg_t *)&bleAdvCfg;
+}
+
+void ble_adv_setup(void)
+{
+	/* set advertising and scan response data for discoverable mode */
+	if (config_get_boolean_with_default("ble_hid_enable", false)) {
+		AppAdvSetData(
+			APP_ADV_DATA_DISCOVERABLE,
+			sizeof(bleAdvDataDiscHID),
+			(uint8_t *)bleAdvDataDiscHID
+		);
+	} else {
+		AppAdvSetData(
+			APP_ADV_DATA_DISCOVERABLE,
+			sizeof(bleAdvDataDisc),
+			(uint8_t *)bleAdvDataDisc
+		);
+	}
+
+	AppAdvSetData(
+		APP_SCAN_DATA_DISCOVERABLE,
+		sizeof(bleScanDataDisc),
+		(uint8_t *)bleScanDataDisc
+	);
+
+	/* set advertising and scan response data for connectable mode */
+	AppAdvSetData(
+		APP_ADV_DATA_CONNECTABLE,
+		sizeof(bleAdvDataConn),
+		(uint8_t *)bleAdvDataConn
+	);
+	AppAdvSetData(APP_SCAN_DATA_CONNECTABLE, 0, NULL);
+
+	bleAdvCfg.advInterval[0] = DEFAULT_ADV_INTERVAL_US / 625;
+}
+
+void ble_adv_set_interval(uint32_t interval_us)
+{
+	bleAdvCfg.advInterval[0] = interval_us / 625;
+	tainted                  = true;
+}
+
+void ble_adv_stop(void)
+{
+	if (advertising_mode != APP_MODE_NONE) {
+		advertising_mode_target = APP_MODE_NONE;
+		advertising_mode        = APP_MODE_NONE;
+		AppAdvStop();
+	}
+}
+
+static void adv_start(uint8_t mode)
+{
+	if (advertising_mode != APP_MODE_NONE) {
+		/* We need to stop advertising in between or the
+		* adv set will not be changed.
+		* Also need to wait for the stop operation to finish
+		* before we can start again
+		* Also need to set the variables first as we don't
+		* have a lock on the stack.*/
+		advertising_mode_target = mode;
+		advertising_mode        = APP_MODE_NONE;
+		AppAdvStop();
+	} else {
+		advertising_mode        = mode;
+		advertising_mode_target = mode;
+		AppAdvStart(advertising_mode);
+	}
+	tainted = false;
+}
+
+void ble_adv_start(uint8_t mode)
+{
+	adv_start(mode);
+	tainted = true;
+}
+
+void ble_adv_discoverable(bool discoverable)
+{
+	if (discoverable) {
+		if (advertising_mode != APP_MODE_DISCOVERABLE || tainted) {
+			LOG_INFO("ble", "Making bondable and discoverable");
+			adv_start(APP_MODE_DISCOVERABLE);
+		}
+	} else {
+		/* TODO: This does way more than the function name indicates */
+		if (AppDbCheckBonded()) {
+			if (advertising_mode != APP_MODE_CONNECTABLE ||
+			    tainted) {
+				LOG_INFO("ble", "Bonded. Making connectable");
+				adv_start(APP_MODE_CONNECTABLE);
+			}
+		} else {
+			LOG_INFO("ble", "Not bonded. Stop advertising");
+			ble_adv_stop();
+		}
+	}
+}