Am a part research scholar & part freelance design engineer, and for one of my project I needed to monitor couple of parameters like Temperature, humidity, light intensity. Using datalogger to perform this task was pretty obvious.
And I don’t have to tell you, how easy it is these days, to build simple datalogger with platform like Arduino.
Earlier, I have built Xbee based simple wireless node for similar applications. But I wanted to do more than that, I wanted to challenge myself.
[I just love to discover new things... Going in to Unknown]
I decided to build WiFi datalogger which will log the data to cloud platform like Thingspeak, Temboo.
I am impressed by its intuitive graphing, simplicity and readiness to export the data and further perform data analysis using MATLAB.
Another reason to choose WiFi, I wanted to try it and ESP8266 was affordable & easy to interface.
I shared this with my research-mates and apparently they were also looking for something like this for monitoring solar panel voltages.
The main reason to design the WiFio-Mini was 3V3 powered, WiFi-enabled board integrated with low cost and easy to read sensors.
Another reason was to simplify the realization of IoT application and speed-up the prototyping process. I just wanted to remove the complexity and errors involved due to in-compatible Logic levels [3V/5V] with sensors and RF modules. And no need to mention wiring, I have spent hours debugging them.
Why Atmega328P-DIP [With Arduino Core]: Arduino, SIMPLE yet Powerful programming language.
Why ESP-01: One of the widely used and accepted by electronics-enthu community. Simple Serial interface with AT commands. Readily available and low cost.
Why MCP9700: Temperature sensor with 10mV/˚C output. Instantly start monitoring temperature in the surrounding. Industry standard.
Why LDR: Get you started in measuring light intensity in the area. Low cost and easily available.
Why FTDI Header: Most trusted interface for Powering, Flashing sketches and Serial comm./debugging using USB-to-TTL 6-Pin module.
Why GPIO: Inspired by "Real Barebones Arduino" made by Paul Badger over at Modern Device.
Why +3V3: Now a days, Most of the Sensors and Wireless modules support/need 3V operations. Again we need to take care of Logic Level conversion otherwise we end up burning the module.
- MCU: Atmega328P-DIP With Arduino Core.
- Wireless Module: ESP-01 [ESP8266].
- Sensors: MCP9700 and LDR.
- Programming Interface: FTDI Header for Powering, Flashing sketches and Serial communication.
- GPIO: Arduino Compatible Digital and Analog I/O.
- Power: +3V3 Powered[LM1117 REG.] and Power Jack for External Source[7-12V].
- Clock Speed: 8MHz Crystal.