How to Make a Temperature Gun With ESP32

What a hot day it is! Too hot to drive and ride and I am thinking of making a temperature measurement sensor. With FireBeetle ESP32 produced by DFRobot and MLX90614 (a noncontact IR temperature sensor) on hand, let’s do it!

Hardware in need

Hardware List

• FireBeetle ESP32 IOT Microcontroller (Supports Wi-Fi & Bluetooth) ×1

• Gravity: Non-contact IR Temperature Sensor for Arduino ×1

• Gravity I2C OLED-2864 Display ×1

• 3.7V 400mAh Lithium battery ×1

• Red laser transmitter (diameter: 6mm) ×1

• C&K slide switch ×1

• 3D printing crust set (2 parts) ×1

Tools

• Thermo-control Anti-Static Soldering Station AT936b

• Overlord Pro 3D printer

• 401 glue Hot melt gun

Software list

• MLX90614.py (library file of MLX90614 noncontact IR temperature sensor) SSD1306.py (library file of Gravity IIC OLED-2864 display)

• piclib.py (library file of show pictures and 16*24 script used in the project) InfraRedThermometer.py (source files of project codes)

• uPyCraft MicroPython IDE

• PCtoLCD2002 LCD impression taking software

• 3D printing slice software: Cura

• 3D printing file: 3D print - left part.stl (available for direct printing of Overload Pro 3D printer)

• 3D printing file: 3D print - right part.stl

Operating process

1. Solder components as below:

Connection diagram

2. Transform show pictures and 16*24 script in use to hexadecimal code with PCtoLCD2002 LCD impression taking software

3. Programing with uPyCraft MicroPython IDE and burn codes to FireBeetle ESP32.

Check after codes burnt.

import MLX90614 
from machine import Pin,I2C 
import time 
import ssd1306 
from piclib import * 
# This code will show you how to make a Infra Red Thermometer using the MLX90614 sensor. 
i2c = I2C(scl=Pin(22), sda=Pin(21), freq=100000) 
ir=MLX90614.MLX90614(i2c) 
lcd=ssd1306.SSD1306_I2C(128,64,i2c) 
#Display a picture 72*64  
def DisplayPicture(x,y,picture): 
 for line in range(0,64): 
   for bytes in range(0,9): 
     for bits in range(0,8): 
       if picture[9*line+bytes]&0x80>>bits: 
         lcd.pixel(x+bytes*8+bits,y+line,1) 
       else: 
         lcd.pixel(x+bytes*8+bits,y+line,0) 
 return 
#Display a character 16*24  
def DisplayCharacter16X24(x,y,character): 
 for line in range(0,24): 
   for bytes in range(0,2): 
     for bits in range(0,8): 
       if character[line*2+bytes]&0x80>>bits: 
         lcd.pixel(x+bytes*8+bits,y+line,1) 
       else: 
         lcd.pixel(x+bytes*8+bits,y+line,0) 
 return 
#---------------------run here------------------------------------   
#display logo 
DisplayPicture(28,0,picture)  
lcd.show() 
time.sleep(1) 
lcd.fill(0) 
#display O:123.4C 
#        A:123.4C  
DisplayCharacter16X24(0,0,charArray[10]) #O 
DisplayCharacter16X24(16*1,0,charArray[12]) #: 
DisplayCharacter16X24(16*7,0,charArray[13]) #C 
DisplayCharacter16X24(0,24,charArray[11]) #A 
DisplayCharacter16X24(16*1,24,charArray[12]) #: 
DisplayCharacter16X24(16*7,24,charArray[13]) #C 
lcd.show() 
while True: 
 time.sleep(0.2) 
 Object = ir.getObjCelsius() #  *C 
 Ambient = ir.getEnvCelsius() # *C 
 #Object = ir.getObjFahrenheit() # *F 
 #Ambient = ir.getEnvFahrenheit() # *F 
 #print("Object  %s *C"% Object) 
 #print("Ambient %s *C"% Ambient) 
 #print() 
 ObjectInt = int(Object*10) 
 AmbientInt = int(Ambient*10) 
 if ObjectInt < 0: 
   ObjectInt = abs(ObjectInt) 
   DisplayCharacter16X24(16*2,0,charArray[15])# - 
   temp1 = (ObjectInt%1000)//100 
   if(temp1 == 0): 
     DisplayCharacter16X24(16*3,0,charArray[16]) # space 
   else: 
     DisplayCharacter16X24(16*3,0,charArray[temp1]) 
   DisplayCharacter16X24(16*4,0,charArray[(ObjectInt%100)//10]) 
   DisplayCharacter16X24(16*5,0,charArray[14]) # . 
   DisplayCharacter16X24(16*6,0,charArray[ObjectInt%10])  
 else: 
   temp1 = ObjectInt//1000 
   temp2 = (ObjectInt%1000)//100 
   if temp1 == 0: 
     DisplayCharacter16X24(16*2,0,charArray[16]) # space 
   else: 
     DisplayCharacter16X24(16*2,0,charArray[temp1]) 
   if temp1 == 0 and temp2 == 0: 
     DisplayCharacter16X24(16*3,0,charArray[16]) # space 
   else: 
     DisplayCharacter16X24(16*3,0,charArray[temp2]) 
   DisplayCharacter16X24(16*4,0,charArray[(ObjectInt%100)//10]) 
   DisplayCharacter16X24(16*5,0,charArray[14]) # . 
   DisplayCharacter16X24(16*6,0,charArray[ObjectInt%10])  
 if AmbientInt < 0: 
   ObjectInt = abs(AmbientInt) 
   DisplayCharacter16X24(16*2,24,charArray[15])# - 
   temp1 = (AmbientInt%1000)//100 
   if temp1 == 0: 
     DisplayCharacter16X24(16*3,24,charArray[16]) # space 
   else: 
     DisplayCharacter16X24(16*3,24,charArray[temp1]) 
   DisplayCharacter16X24(16*4,24,charArray[(AmbientInt%100)//10]) 
   DisplayCharacter16X24(16*5,24,charArray[14]) # . 
   DisplayCharacter16X24(16*6,24,charArray[AmbientInt%10])  
 else: 
   temp1 = AmbientInt//1000 
   temp2 = (AmbientInt%1000)//100 
   if temp1 == 0: 
     DisplayCharacter16X24(16*2,24,charArray[16]) # space 
   else: 
     DisplayCharacter16X24(16*2,24,charArray[temp1]) 
   if temp1 == 0 and temp2 == 0: 
     DisplayCharacter16X24(16*3,24,charArray[16]) # space 
   else: 
     DisplayCharacter16X24(16*3,24,charArray[temp2]) 
   DisplayCharacter16X24(16*4,24,charArray[(AmbientInt%100)//10]) 
   DisplayCharacter16X24(16*5,24,charArray[14]) # . 
   DisplayCharacter16X24(16*6,24,charArray[AmbientInt%10])   
 lcd.show() 

4. Designing crusts according to dimension of components.

5. Use Cura (a 3D printing slice software) to make 3D printing files.

6. Print crusts with Overload Pro 3D printer.

7. Allocate components to inner part of printed crusts with hot melt and glue.

8. Temperature measurement

Measure temperature of palm

Measure temperature of mobile saddle: