The main objective of this project was to design a general purpose web based data acquisition and control unit. The heart of the entire setup is the FRDM KL25Z development board from Freescale semiconductors. The Kinetis L series MCU is used to sample data from a number of connected sensors (light, humidity, temperature, current, gas sensors etc.). The sampled data is then transferred wirelessly via a RF Module to a Windows/Linux based system running the server code. The server then uploads the incoming data to a website making the system accessible from anywhere with an active internet connection. Also, the Web UI enables the user to control various connected control units with multiple control modes (ON/OFF, PWM etc.) by sending appropriate control instructions to the MCU. The on board 16-bit, 6-channel ADC, 3-axis accelerometer and the serial UART peripheral along with the associated ICs forms the hardware data acquisition system. The server side is implemented using node.js.
FRDM KL25Z development board
A Kinetic L Series MCU
ULN2803 Darlington transistor array
for driving output peripherals