Introduction: In this project, I am trying to ensure a direct communication between STM32F4 and Raspberry Pi 2, Those two boards are connected through a serial communication ( UART ) which is the process of sending data bit by bit sequentially . In the meanwhile i will upload the same data to an IOT platform named “ ThingSpeak ” using the http protocol . Description: the main task is to collect live data from LDR sensor and send it to thingspeak to be plotted in a graph. As a start , let’s write a small code on the IAR E mbedded W orkbench for ARM and upload it to the STM32F4 board . EWARM is a development environment that includes a C/C++ compiler and debugger . To make the task a bit easier , i’ve used the STM32cubeMX which is a graphical software configuration tool that allows generating C initialization code using graphical wizards. ThingSpeak : a brief definition : how it works ? ThingSpeak is an open