Golioth Bluetooth Gateway Demo

main.c

/* main.c - Application main entry point */

/*
 * Copyright (c) 2020 SixOctets Systems
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <stdio.h>
#include <stddef.h>
#include <errno.h>

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/sys/byteorder.h>

#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/uuid.h>
#include <zephyr/bluetooth/gatt.h>

#include <golioth/client.h>
#include <golioth/stream.h>
#include <samples/common/net_connect.h>
#include <samples/common/sample_credentials.h>

static struct golioth_client *client;
static K_SEM_DEFINE(golioth_connected, 0, 1);

static void on_client_event(struct golioth_client *client, enum golioth_client_event event,
			    void *arg)
{
	bool is_connected = (event == GOLIOTH_CLIENT_EVENT_CONNECTED);
	if (is_connected) {
		k_sem_give(&golioth_connected);
	}
	printk("Golioth client %s\n", is_connected ? "connected" : "disconnected");
}

static int scan_start(void);

static struct bt_conn *default_conn;
static struct bt_uuid_16 discover_uuid = BT_UUID_INIT_16(0);
static struct bt_gatt_discover_params discover_params;
static struct bt_gatt_subscribe_params subscribe_params;

static double pow(double x, double y)
{
	double result = 1;

	if (y < 0) {
		y = -y;
		while (y--) {
			result /= x;
		}
	} else {
		while (y--) {
			result *= x;
		}
	}

	return result;
}

static uint8_t notify_func(struct bt_conn *conn,
			   struct bt_gatt_subscribe_params *params,
			   const void *data, uint16_t length)
{
	double temperature;
	uint32_t mantissa;
	int8_t exponent;

	if (!data) {
		printk("[UNSUBSCRIBED]\n");
		params->value_handle = 0U;
		return BT_GATT_ITER_STOP;
	}

	/* temperature value display */
	mantissa = sys_get_le24(&((uint8_t *)data)[1]);
	exponent = ((uint8_t *)data)[4];
	temperature = (double)mantissa * pow(10, exponent);

	printf("Temperature %gC.\n", temperature);

	char sbuf[32];
	snprintk(sbuf, sizeof(sbuf), "{\"temperature\":%g}", temperature);
	printf("Sending to Golioth: %s\n", sbuf);


	int err = golioth_stream_set_async(client,
					   "sensor",
					   GOLIOTH_CONTENT_TYPE_JSON,
					   sbuf,
					   strlen(sbuf),
					   NULL,
					   NULL);
	if (err) {
		printf("Failed to push temperature: %d\n", err);
	}

	return BT_GATT_ITER_CONTINUE;
}

static uint8_t discover_func(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;

	if (!attr) {
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("[ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_HTS)) {
		memcpy(&discover_uuid, BT_UUID_HTS_MEASUREMENT, sizeof(discover_uuid));
		discover_params.uuid = &discover_uuid.uuid;
		discover_params.start_handle = attr->handle + 1;
		discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &discover_params);
		if (err) {
			printk("Discover failed (err %d)\n", err);
		}
	} else if (!bt_uuid_cmp(discover_params.uuid,
				BT_UUID_HTS_MEASUREMENT)) {
		memcpy(&discover_uuid, BT_UUID_GATT_CCC, sizeof(discover_uuid));
		discover_params.uuid = &discover_uuid.uuid;
		discover_params.start_handle = attr->handle + 2;
		discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &discover_params);
		if (err) {
			printk("Discover failed (err %d)\n", err);
		}
	} else {
		subscribe_params.notify = notify_func;
		subscribe_params.value = BT_GATT_CCC_INDICATE;
		subscribe_params.ccc_handle = attr->handle;

		err = bt_gatt_subscribe(conn, &subscribe_params);
		if (err && err != -EALREADY) {
			printk("Subscribe failed (err %d)\n", err);
		} else {
			printk("[SUBSCRIBED]\n");
		}

		return BT_GATT_ITER_STOP;
	}

	return BT_GATT_ITER_STOP;
}

static void connected(struct bt_conn *conn, uint8_t conn_err)
{
	char addr[BT_ADDR_LE_STR_LEN];
	int err;

	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

	if (conn_err) {
		printk("Failed to connect to %s (%u)\n", addr, conn_err);

		bt_conn_unref(default_conn);
		default_conn = NULL;

		scan_start();
		return;
	}

	printk("Connected: %s\n", addr);

	if (conn == default_conn) {
		memcpy(&discover_uuid, BT_UUID_HTS, sizeof(discover_uuid));
		discover_params.uuid = &discover_uuid.uuid;
		discover_params.func = discover_func;
		discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			return;
		}
	}
}

static bool eir_found(struct bt_data *data, void *user_data)
{
	bt_addr_le_t *addr = user_data;
	int i;

	printk("[AD]: %u data_len %u\n", data->type, data->data_len);

	switch (data->type) {
	case BT_DATA_UUID16_SOME:
	case BT_DATA_UUID16_ALL:
		if (data->data_len % sizeof(uint16_t) != 0U) {
			printk("AD malformed\n");
			return true;
		}

		for (i = 0; i < data->data_len; i += sizeof(uint16_t)) {
			struct bt_uuid *uuid;
			uint16_t u16;
			int err;

			memcpy(&u16, &data->data[i], sizeof(u16));
			uuid = BT_UUID_DECLARE_16(sys_le16_to_cpu(u16));
			if (bt_uuid_cmp(uuid, BT_UUID_HTS)) {
				continue;
			}

			err = bt_le_scan_stop();
			if (err) {
				printk("Stop LE scan failed (err %d)\n", err);
				continue;
			}

			err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN,
						BT_LE_CONN_PARAM_DEFAULT,
						&default_conn);
			if (err) {
				printk("Create connection failed (err %d)\n",
				       err);
				scan_start();
			}

			return false;
		}
	}

	return true;
}

static void device_found(const bt_addr_le_t *addr, int8_t rssi, uint8_t type,
			 struct net_buf_simple *ad)
{
	char dev[BT_ADDR_LE_STR_LEN];

	bt_addr_le_to_str(addr, dev, sizeof(dev));
	printk("[DEVICE]: %s, AD evt type %u, AD data len %u, RSSI %i\n",
	       dev, type, ad->len, rssi);

	/* We're only interested in connectable events */
	if (type == BT_HCI_ADV_IND || type == BT_HCI_ADV_DIRECT_IND) {
		bt_data_parse(ad, eir_found, (void *)addr);
	}
}

static int scan_start(void)
{
	/* Use active scanning and disable duplicate filtering to handle any
	 * devices that might update their advertising data at runtime.
	 */
	struct bt_le_scan_param scan_param = {
		.type       = BT_LE_SCAN_TYPE_ACTIVE,
		.options    = BT_LE_SCAN_OPT_NONE,
		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
		.window     = BT_GAP_SCAN_FAST_WINDOW,
	};

	return bt_le_scan_start(&scan_param, device_found);
}

static void disconnected(struct bt_conn *conn, uint8_t reason)
{
	char addr[BT_ADDR_LE_STR_LEN];
	int err;

	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

	printk("Disconnected: %s (reason 0x%02x)\n", addr, reason);

	if (default_conn != conn) {
		return;
	}

	bt_conn_unref(default_conn);
	default_conn = NULL;

	err = scan_start();
	if (err) {
		printk("Scanning failed to start (err %d)\n", err);
	}
}

BT_CONN_CB_DEFINE(conn_callbacks) = {
	.connected = connected,
	.disconnected = disconnected,
};

int main(void)
{
	net_connect();
	const struct golioth_client_config *client_config = golioth_sample_credentials_get();
	client = golioth_client_create(client_config);
	golioth_client_register_event_callback(client, on_client_event, NULL);

	k_sem_take(&golioth_connected, K_FOREVER);

	int err;

	err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return 0;
	}

	printk("Bluetooth initialized\n");

	err = scan_start();

	if (err) {
		printk("Scanning failed to start (err %d)\n", err);
		return 0;
	}

	printk("Scanning successfully started\n");
	return 0;
}

nrf9160dk_nrf9160_ns.conf

# General config
CONFIG_HEAP_MEM_POOL_SIZE=4096
CONFIG_NEWLIB_LIBC=y

# Networking
CONFIG_NET_SOCKETS_OFFLOAD=y
CONFIG_NET_IPV6=y
CONFIG_NET_IPV6_NBR_CACHE=n
CONFIG_NET_IPV6_MLD=n

# Increase native TLS socket implementation, so that it is chosen instead of
# offloaded nRF91 sockets
CONFIG_NET_SOCKETS_TLS_PRIORITY=35

# Modem library
CONFIG_NRF_MODEM_LIB=y
CONFIG_NRF_MODEM_LIB_ON_FAULT_APPLICATION_SPECIFIC=y

# LTE connectivity with network connection manager
CONFIG_LTE_CONNECTIVITY=y
CONFIG_NET_CONNECTION_MANAGER=y
CONFIG_NET_CONNECTION_MANAGER_MONITOR_STACK_SIZE=1024

# Increased sysworkq size, due to LTE connectivity
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

# Disable options y-selected by NCS for no good reason
CONFIG_MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED=n
CONFIG_MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED=n

# Generate MCUboot compatible images
CONFIG_BOOTLOADER_MCUBOOT=y

# UART from BLE LTE gateway board config
CONFIG_NRF_SW_LPUART=y
CONFIG_NRF_SW_LPUART_INT_DRIVEN=y

CONFIG_UART_2_ASYNC=y
CONFIG_UART_2_INTERRUPT_DRIVEN=n
CONFIG_UART_2_NRF_HW_ASYNC=y
CONFIG_UART_2_NRF_HW_ASYNC_TIMER=2

nrf9160dk_nrf9160_ns.overlay

#include <nrf9160dk_nrf52840_reset_on_if5.dtsi>

/ {
	chosen {
		zephyr,bt-uart=&lpuart;
	};
};

&gpiote {
	interrupts = <49 NRF_DEFAULT_IRQ_PRIORITY>;
};

&uart2 {
	current-speed = <1000000>;
	status = "okay";
	/delete-property/ hw-flow-control;

	pinctrl-0 = <&uart2_default_alt>;
	pinctrl-1 = <&uart2_sleep_alt>;
	pinctrl-names = "default", "sleep";
	lpuart: nrf-sw-lpuart {
		compatible = "nordic,nrf-sw-lpuart";
		status = "okay";
		req-pin = <21>; /* <&interface_to_nrf52840 3 0>; */
		rdy-pin = <19>; /* <&interface_to_nrf52840 2 0>; */
	};
};

&pinctrl {
	uart2_default_alt: uart2_default_alt {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 18)>,
				<NRF_PSEL(UART_RX, 0, 17)>;
		};
	};

	uart2_sleep_alt: uart2_sleep_alt {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 18)>,
				<NRF_PSEL(UART_RX, 0, 17)>;
			low-power-enable;
		};
	};
};

nrf9160dk_nrf9160_ns_0_14_0.overlay

/* Use the reset line that is available starting from v0.14.0 of the DK. */
#include <nrf9160dk_nrf52840_reset_on_if9.dtsi>

prj.conf

# Golioth Firmware SDK with all dependencies
CONFIG_GOLIOTH_FIRMWARE_SDK=y

# Application
CONFIG_MAIN_STACK_SIZE=2048
CONFIG_GOLIOTH_SAMPLE_COMMON=y
CONFIG_LOG_BACKEND_GOLIOTH=y
CONFIG_GOLIOTH_SETTINGS=y
CONFIG_GOLIOTH_STREAM=y

CONFIG_GOLIOTH_SAMPLE_HARDCODED_CREDENTIALS=n

CONFIG_FLASH=y
CONFIG_FLASH_MAP=y
CONFIG_NVS=y

CONFIG_SHELL=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_RUNTIME=y
CONFIG_GOLIOTH_SAMPLE_PSK_SETTINGS=y
CONFIG_GOLIOTH_SAMPLE_SETTINGS_AUTOLOAD=y
CONFIG_GOLIOTH_SAMPLE_SETTINGS_SHELL=y

CONFIG_LOG=y
CONFIG_EVENTFD_MAX=14
CONFIG_LOG_PROCESS_THREAD_STACK_SIZE=1536
CONFIG_MBEDTLS_ENABLE_HEAP=y
CONFIG_MBEDTLS_HEAP_SIZE=10240
CONFIG_MBEDTLS_SSL_IN_CONTENT_LEN=2048
CONFIG_MBEDTLS_SSL_OUT_CONTENT_LEN=2048
CONFIG_NETWORKING=y
CONFIG_NET_IPV4=y
CONFIG_POSIX_MAX_FDS=23

# Enable Bluetooth stack and libraries
CONFIG_BT=y
CONFIG_LOG=y
CONFIG_BT_CENTRAL=y
CONFIG_BT_SMP=y
CONFIG_BT_GATT_CLIENT=y
CONFIG_CBPRINTF_FP_SUPPORT=y