Published April 4, 2022

Hexabitz Infrared thermometer

This project is about building a monitoring and control system for water heating with Hexabitz modules.

IntermediateFull instructions provided2 hours258

Things used in this project

Hardware components

Hexabitz Thermopile Sensor (H09R9)

Hexabitz SPDT Mechanical DC Relay (H0FR1x)

Hexabitz Bluetooth V4.0 Dual Mode Module (H23R10)

Hexabitz 4-Pin USB-Serial Prototype Cable

Hexabitz BitzClamp

Software apps and online services

STMicroelectronics STM32CUBEPROG

MIT App Inventor

Story

Hexabitz Thermopile Sensor is a great tool to measure the temperature of objects without physical contact and can be used in industrial process control, robots or household.

In this project, we used Hexabitz Thermopile Sensor Module (H09R9) to measure the water temperature in the heater and display it to the user, who can determine the desired temperature through an Android app. For this purpose, we used Hexabitz Bluetooth Module (H23R1) and Hexabitz SPDT Mechanical DC Relay Module (H0FR1).

Steps to implement the project

We give you step by step instructions from the conception to the implementation of the project :

1. Planning the array and assembling the hardware:

First, we prepare the project parts and plan our array design by aligning the three modules side by side. Then we solder the modules together using Hexabitz Fixture.

Figure (1) : Assembling the project's hardware

2. Writing codes with STM32CubeIDE software:

After creating the topology for the three modules and setting their configurations, we add the topology for each module. See this link for help in creating a topology file.

First, we defined our temperature sensor variable in the main.c file of the Thermopile Sensor (H09R9) module:

Then we initialized this variable in the user task function as BOS variable to share its value with other modules. To do this, we use the following API from the BOS factsheet:

Figure (2) : Link to BOS variables API

And in the repeated closed loop, we made sure that MC periodically checks the temperature value of the sensor using the API from H09R9 factsheet and sends it to the Bluetooth module (H23R1) using the API from the BOS factsheet:

1 / 3 • Figure (3) : H09R9 get temperature value in Celsius API

Second, in the main.c file of the Bluetooth module (H23R1), we defined the variable for the temperature sensor with the same name and as a public variable so that it can be changed by the thermopile sensor module (H09R9), and then defined the other variables used in the code.

In the user task function, we initialized the Bluetooth properties to be discoverable and set the Bluetooth name using the APIs from the Bluetooth module (H23R1) factsheet:

1 / 2

Then we initialized the variable for the temperature sensor as BOS variable, as we had done in the code of the module Thermopile Sensor (H09R9).

In the repeated closed loop, the MC stores the received message in an array using the API from the H23R1 factsheet :

1 / 2

Then it checks if the message is a command to switch the relay ON or OFF, then it checks if the message is a command to get the sensor temperature, and if so, it converts the variable value and sends the result to the Android app using the API from the H23R1 factsheet :

1 / 2

Then it checks if the message contains the desired temperature value, and if so, it converts the value and stores it. Then it sends a message to the SPDT mechanical relay module DC (H0FR1) to switch the relay ON or OFF, depending on whether the user has changed the switch in the Android app, and based on the comparison result between the sensor temperature and the desired temperature.

1 / 2

3. Creating an Android app using MIT App Inventor :

Below you can see the application screen where there is a button that, when clicked, will automatically pair the Android phone with the specific MAC address of the Bluetooth module specified in the Android application code. Pairing with this address must be done in advance.

The ON / OFF switch sends a Bluetooth message from the Android phone to the Bluetooth module. Below the switch, the current operating status of the heater is displayed. Below that, the app shows the user the desired temperature, which can be changed with the thumb switch, and finally the value of the temperature detected by the thermosensor.

Figure (5) : The Android app screen

Results :

The following video shows the final results of our project, enjoy watching!

Code

/*
 BitzOS (BOS) V0.2.6 - Copyright (C) 2017-2022 Hexabitz
 All rights reserved

 File Name     : topology.h
 Description   : Array topology definition.

 */

/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __topology_H
#define __topology_H
#ifdef __cplusplus
 extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "stm32f0xx_hal.h"

#define __N	3		//3			// Number of array modules

// Array modules
#define _mod1	1<<3
#define _mod2	2<<3
#define _mod3	3<<3

// Topology
static uint16_t array[__N ][7] ={
	{_H09R9, _mod2 | P4, 0, 0, _mod3 | P1, 0, 0}, 	 // Module 1 
	{_H0FR6, 0, 0, 0, _mod1 | P1, 0, 0},			     // Module 2
	{_H23R1, _mod1 | P4, 0, 0, 0, 0, 0},					     // Module 3
};

// Configurations for duplex serial ports
#if ( _module == 1 )
	#define	H09R9	1
	#define	_P1pol_normal	1
	#define	_P2pol_normal	1
	#define	_P3pol_normal	1
	#define	_P4pol_normal	1
	#define	_P5pol_normal	1
	#define	_P6pol_normal	1
#endif

#if ( _module == 2 )
	#define	H0FR6	1
	#define	_P1pol_normal	1
	#define	_P2pol_normal	1
	#define	_P3pol_normal	1
	#define	_P4pol_reversed	1
	#define	_P5pol_normal	1
	#define	_P6pol_normal	1

#endif

#if ( _module == 3 )
	#define	H23R1	1
	#define	_P1pol_reversed	1
	#define	_P2pol_normal	1
	#define	_P3pol_normal	1
	#define	_P4pol_normal	1
	#define	_P5pol_normal	1
	#define	_P6pol_normal	1

#endif

#ifdef __cplusplus
}
#endif
#endif /*__ topology_H */

/************************ (C) COPYRIGHT HEXABITZ *****END OF FILE****/

/*
 BitzOS (BOS) V0.2.6 - Copyright (C) 2017-2022 Hexabitz
 All rights reserved

 File Name     : main.c
 Description   : Main program body.
 */
/* Includes ------------------------------------------------------------------*/
#include "BOS.h"

/* Private variables ---------------------------------------------------------*/
float	temp_s;
/* Private function prototypes -----------------------------------------------*/

/* Main function ------------------------------------------------------------*/

int main(void){

	Module_Init();		//Initialize Module &  BitzOS

	//Don't place your code here.
	for(;;){}
}

/*-----------------------------------------------------------*/

/* User Task */
void UserTask(void *argument){
	BOSMessaging.trace = TRACE_NONE ;
	AddBOSvar(FMT_FLOAT,(uint32_t) &temp_s );

	while(1){
		SampleTemperature(&temp_s);
		WriteRemote(3, (uint32_t) &temp_s, 1, FMT_FLOAT, 0);
	}
}

/*-----------------------------------------------------------*/

/*
 BitzOS (BOS) V0.2.6 - Copyright (C) 2017-2022 Hexabitz
 All rights reserved

 File Name     : main.c
 Description   : Main program body.
 */
/* Includes ------------------------------------------------------------------*/
#include "BOS.h"

/* Private variables ---------------------------------------------------------*/
volatile float temp_s;
int temp_u;
uint8_t buf[4];
uint8_t MESG_T[4];
uint8_t MESG_U[3] ;
float	timeout	=	60000;
int Relay = 0;
/* Private function prototypes -----------------------------------------------*/

/* Main function ------------------------------------------------------------*/

int main(void){

	Module_Init();		//Initialize Module &  BitzOS

	//Don't place your code here.(uint32_t) 0xFFFFFFFF
	for(;;){}
}

/*-----------------------------------------------------------*/

/* User Task */
void UserTask(void *argument){
	 BT_Set_Discoverable();
	 BT_Set_Name(&("H23R1"), 5);
	AddBOSvar(FMT_FLOAT, (uint32_t)&temp_s);

	// put your code here, to run repeatedly.
	while(1){

		BT_Receive_Data(buf,3);

		if(buf[0]=='1'&&buf[1]=='s')
		Relay = 1;

		else if (buf[0]=='0'&&buf[1]=='s')
		Relay = 0;

		else if (buf[0]=='g')
		{	sprintf(MESG_T, "%f",temp_s);
			BT_Send_Data(MESG_T, 4);
		}

		else if (buf[0]=='t')
		{	MESG_U[0]=buf[1];
			MESG_U[1]=buf[2];
			MESG_U[2]=buf[3];
			temp_u = atoi(MESG_U);}


		if((temp_u > temp_s)&&(Relay == 1) ){
			memcpy(&messageParams[0], &timeout, 4);
			SendMessageToModule(2, CODE_H0FRx_ON, 4);}

		else if ((Relay == 0) || (temp_u < temp_s) )
		{ SendMessageToModule(2, CODE_H0FRx_OFF, 0);}

	}
}

/*-----------------------------------------------------------*/

Credits

Ibrahim Zaeiter

2 projects • 12 followers

Electronic Systems Engineer

Hexabitz Infrared thermometer

Things used in this project

Hardware components

Software apps and online services

Story

Steps to implement the project

2. Writing codes with STM32CubeIDE software:

3. Creating an Android app using MIT App Inventor :

Results :

Schematics

MIT APP INVENTOR project

Modules Firmware files

Code

topology.h

H09R9 main.c

H23R0 main.c

Credits

Ibrahim Zaeiter

Comments

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Hexabitz Infrared thermometer

Hexabitz Infrared thermometer

Things used in this project

Hardware components

Software apps and online services

Story

Steps to implement the project

2. Writing codes with STM32CubeIDE software:

3. Creating an Android app using MIT App Inventor :

Results :

Schematics

MIT APP INVENTOR project

Modules Firmware files

Code

topology.h

H09R9 main.c

H23R0 main.c

Credits

Ibrahim Zaeiter

Comments

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