Monitor the temperature via SMS using PIC18F4550 of Microchip + M95 (GSM) of Quectel

MCU Development


  Posts user guide to programming application monitoring and warning temperature using GSM/GPRS M95 Easy combined with PIC Easy R1 because the AT-COM production. The temperature sensor used is LM35DZ. The open source code was written to run compatibly USB HiD Bootloader of PIC Easy R1. The user can "Plug and Play" thanks to the flexibility of the ATCBus on each product.

    1. Introduction of PIC Easy R1

  PIC Easy R1 is a product of AT-COM brings users the convenience when combine between ATCBus and PIC18F4550-I/PT microcontroller series of Microchip. Board support to connect computer via USB Full Speed 2.0 V, with USB HID Bootloader allows users to load firmware directly to the PIC18F4550-I/PT without any other programming kit. Besides, the PIC18F4550 microcontroller with 48MHz processing speed powerfully to meet the requirements of programmers implementing applications like Wifi, Ethernet, USB, CAN, PWM ...

    2. Introduction of GSM/GPRS M95 Easy

  ModuleM95 is a GSM/GPRS module of Quectel. Module M95 works with GSM850, GSM900 MHz band 4 MHz, DCS1800, PCS1900 MHz MHz. GPRS support multi-M95Module slot class 12, SMS, MMS ... M95 module is integrated with Internet protocols such as TCP/IP, UDP, FTP and PPP, is controlled according to the AT command set Protocol Command.


    GSM/GPRS M95 Easy is a product by AT-COM development based on the feature of modules M95GSM/GPRS M95 Easy is designed with SIMCARD is integrated on the circuit, GSM built-in PIFA Antenna, earphone/microphone jack helps users to easily research and deploy the applications related to GSM/GPRS as: controls, monitor, collect data remotely via GPRS, SMS ... Besides, with compact size, handy data outputs, GSM/GPRS M95 Easy will bring inspiration to the modern and sophisticated design.

    3. Application monitoring and temperature alerts via SMS

  To accomplish this, we need the following equipment:

      - PIC Easy R1

      - GSM/GPRS M95 Easy

      - Temperature sensor LM35DZ

    We proceed to connect the system according to the following diagram:

   After connecting the equipment, we proceed to load the code for PIC Easy R1

   Source code GSM/GPRS M95 Easy is presented in the article use the CCS Compiler compiler for PIC18F4550 microcontroller. The code was written according to the USB HID Bootloader of PIC Easy R1, allowing the microcontroller runs with pulse frequency 48MHz. Can download source code in GSM/GPRS M95 Easy.

   Code after the download of the computer needs to be edited and recompiled using the compiler software PIC C Compiler.

 After unpacking, we open the file main. c, proceed to edit the numbers in the code to send the feedback message board monitoring the temperature, the phone number consists of 10 digits.


  Then, we edit the password of the board, password is a 6 digit number.

    After editing the code is finished, we proceed to compile the .hex file.

     The software was compiled successfully.


     Once compiled, we proceed to load the firmware for PIC18F4550 through USB HID Bootloader.

     To enter USB HID Bootloader mode of PIC Easy R1 we do the following:

     Connect PIC Easy R1 with computer through mini USB on board. Then we pressed the hold SW1/RD0 button and press RESET button then PIC Easy R1 will on Hid Bootloader mode. When on Hid Bootloader mode then LD2/RD3 Led will light continuously flashes, waiting for the user to update the Firmware for the PIC18F4550. 

      To load firmware for the user's applications run on PIC Easy R1, the user can use USB Bootloader V2.9j program of Microchip to flash the Firmware to the memory Program Memory of the PIC18F4550.

      After you download the USB Bootloader V 2.9j program about computer, you extract the WinRAR file and click the HIDBootloader.exe file to run the USB Bootloader program on your computer.



  After running the USB Bootloader V2.9j program, you choose to Import Firmware Image and lead the path to where the archive file .hex.



    After Import .hex file successfully, you select the Erase/Program/Verify Device to load the .hex file to memory Program Memory of the PIC18F4550After .hex file loaded successfully you can choose Reset Device to PIC18F4550 ran into application programs that you have programmed.


After the reset PIC, Board boot M95 module and the message boot complete to phone number which we have edited in the code above.

We install temperature warning for the system according to the following syntax:

                                                     #settemp‹distance›‹password›‹distance›‹temperature warning›.

Note: the installation messages start with sharp (#) and end with a dot (.).

When the system detects the temperature exceeded the warning temperature levels, then send a message warning about the phone number has been installed above.


 4. Video demo