wassfila
Published © MIT

Indoor Air Quality with Thingy53 and BME688

A Zephyr integration of BME688 drivers and libraries to create an OpenThread sensors server for IAQ Indoor Air Quality.

AdvancedFull instructions provided4 hours1,126
Indoor Air Quality with Thingy53 and BME688

Things used in this project

Hardware components

Nordic Semiconductor Thingy53
×1
Bosch BME688
×1

Software apps and online services

Zephyr RTOS
Zephyr Project Zephyr RTOS

Story

Read more

Code

Thread Tags MQTT

Python
This script captures UDP packets and posts them as MQTT messages
import paho.mqtt.client as mqtt
import socket 
import logging as log
import cfg
from mqtt import mqtt_start
import thread_tags_homeassistant

def replace_friendly_names(topic,friendlyNames):
    for long_name,short_name in friendlyNames.items():
        topic.replace(long_name,short_name)
    return topic

def run():
    config = cfg.configure_log(__file__)
    if(config["homeassistant"]):
        thread_tags_homeassistant.run()

    UDP_IP = "::" # = 0.0.0.0 u IPv4
    UDP_PORT = config["thread"]["port"]

    sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM) # UDP
    sock.bind((UDP_IP, UDP_PORT))

    #will start a separate thread for looping
    clientMQTT = mqtt_start(config,None,True)

    while True:
        data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
        message = data.decode("utf-8")
        parts = message.split("{")
        topic = parts[0]
        payload = message[len(topic):]
        topic = replace_friendly_names(parts[0],config["friendlyNames"])
        log.info(f"'{topic}' => {payload}")
        clientMQTT.publish(topic,payload)
    return

if __name__ == '__main__':
    run()

Sensors Server main cpp application

C/C++
This is the code of the Sensor server, fetches sensors data and broadcasts the openthread udp packet
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <stdio.h>
#include "json_endpoint.h"
#include "app_ot.h"
#include "app_led.h"
#include "app_battery.h"
#include "udp_broadcast.h"
#include <json.hpp>
#include <zephyr/device.h>
#include <zephyr/drivers/sensor.h>
#include "bme688_server.h"


using json = nlohmann::json;

LOG_MODULE_REGISTER(sensor_server_sample, CONFIG_SONSORS_SERVER_LOG_LEVEL);

const struct device *sensor_dev_bh1749;
const struct device *sensor_dev_bme688;

void send_data(std::string topic,json &data){
	std::string message = topic+data.dump();
	send_udp(message);
	LOG_INF("send_data> %s",message.c_str());
}

void app_bh1749_init(){
	sensor_dev_bh1749 = DEVICE_DT_GET_ONE(rohm_bh1749);
	if (!device_is_ready(sensor_dev_bh1749)) {
		printk("Sensor device bh1749 not ready\n");
		return;
	}
}

void bh1749_get_values(int32_t &r,int32_t &g,int32_t &b,int32_t &ir){
	int ret;
	struct sensor_value temp_val;
	ret = sensor_sample_fetch_chan(sensor_dev_bh1749, SENSOR_CHAN_ALL);
	/* The sensor does only support fetching SENSOR_CHAN_ALL */
	if (ret) {
		printk("sensor_sample_fetch failed ret %d\n", ret);
		return;
	}

	ret = sensor_channel_get(sensor_dev_bh1749, SENSOR_CHAN_RED, &temp_val);
	if (ret) {
		printk("sensor_channel_get failed ret %d\n", ret);
		return;
	}
	r = temp_val.val1;
	ret = sensor_channel_get(sensor_dev_bh1749, SENSOR_CHAN_GREEN, &temp_val);
	if (ret) {
		printk("sensor_channel_get failed ret %d\n", ret);
		return;
	}
	g = temp_val.val1;

	ret = sensor_channel_get(sensor_dev_bh1749, SENSOR_CHAN_BLUE, &temp_val);
	if (ret) {
		printk("sensor_channel_get failed ret %d\n", ret);
		return;
	}
	b = temp_val.val1;

	ret = sensor_channel_get(sensor_dev_bh1749, SENSOR_CHAN_IR, &temp_val);
	if (ret) {
		printk("sensor_channel_get failed ret %d\n", ret);
		return;
	}
	ir = temp_val.val1;
}

void json_endpoint_handler(std::string &client, std::string &topic, json &request, json &response){
	LOG_INF("json_endpoint_handler()");
	response = request;
	response["result"] = "OK";
}

void bme688_handler(json &data){
	send_data("thingy_53/tester/env",data);
}

int main(void)
{
	LOG_INF(R"(
	main()
	sensors server sample
	)");

	app_ot_init();//logs joiner info and initializes reset buttons
	app_led_init();
	app_battery_init();
	app_bh1749_init();
	set_endpoint_handler(json_endpoint_handler);
	start_bme688(bme688_handler);

	app_led_blink_green(0.1,500,1000);

	int count = 0;
	while(1){
		json data;
		
		//state
		data["alive"] = count++;
		int32_t voltage = app_battery_voltage_mv();
		bool is_charging = app_battery_charging();
		data["voltage"] = voltage;
		data["charging"] = is_charging;
		send_data("thingy_53/tester/state",data);
		data = {};
		k_sleep(K_MSEC(5000));

		//light
		int32_t r,g,b,ir;
		bh1749_get_values(r,g,b,ir);
		data["light_red"] = r;
		data["light_green"] = g;
		data["light_blue"] = b;
		data["light_ir"] = ir;
		send_data("thingy_53/tester/light",data);
		data = {};

		app_led_blink_blue(0.08,100,0);

		k_sleep(K_MSEC(5000));
	}
}

Thingy53 Thread Sensors Server

Zephyr Samples for Nordic Thingy53 dev kit OpenThread mesh with json data, BME688 BSEC2 for Air Quality, Light color, RGB Les, Battery

Credits

wassfila
1 project • 3 followers
Passionate about sensors, micro-controllers, computer science, machine learning, python, javascript, embedded systems, back and front end.

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