Bluetooth Wireless Voltage Meter using Wiimote + Pic Chip + AutoIt

In this tutorial I'm going to be showing you how you can send voltage values to your pc using a Pic chip, Wiimote, and Autoit3 scripting language. The process works by wiring a pic chip to the button pads of a wiimote. Then using the pic chips Analog to Digital Converter, we obtain a 10bit binary value. We will then send that value to Autoit in the form of button presses using the wiimote as a data interface.  On the PC side we will use a library I wrote to receive the data from the wiimote. The library is basically just a port to Wiiuse by Michael Laforest set up in a way to make scripting with the wiimote very easy. 

Most pic chips are equiped with multiple Analog to Digital channels. This lets us monitor multiple voltages values if we want to. The total amount of channels sampled will depend on different factors like how many channels the chip has. Channels are sampled one at a time so the more voltages you monitor, the less samples per second you get. 

How the Analog to Digital Converter works
The pic chip A/D Converter works by comparing the voltage you're measuring to a known voltage. In our case the known voltage is the voltage supply 5v. The 10bit value measured is a ratio of the pic chips known voltage 10bit value. So for example a sample thats 10bit value is 387, the voltage value would be V = (5v/1024) * 387    which equals 1.89v

Step 1 Experience, Tools and Parts Needed

Experience:
• Basic understanding of electronics. (Ohms law for example..)
• How to use a bread board and voltage meter.
• How to solder. 
• A little knowledge of pic chips will help, but is not really required since all the pic chip code for the examples is already written.

Tools:
• Voltmeter
• Triwing Screwdriver for wimote. ($2 on ebay)
• Soldering Iron, solder
• Breadboard and Jumper wires
• Pic Chip Programmer (Im using the “Enhanced PICKit 2”) 
• PC with Bluetooth

Parts: ($20 + $1 + $1 + $5 + $7) = $34
• Wiimote -  note that while generic wiimotes will work, a genuine wiimote has best compatibility.     (< $20) 
• Transistors 2N3904 or any General Purpose NPN  Qt: 11  ($1)
• Resistor values 470K (390K to 560K will work):  Qt: 11  ($1)
• Pic Chips (any of these will work since I have included multiple examples)
     - PIC12F683-I/P or PIC12F675-I/P – 2 examples    ($1.25)x2
     - PIC16F616-I/P  -  - 2 examples -    ($1.10)x2
     - shipping for all 4 pic chips   ($7)
• 5v supply for the Pic Chip

Comments

[tom123il]

Thank you for this. I have been playing with 20 of the MotorWave mini windmills and have then set up in my back yard. I was looking for a way to monitor the voltage output and possibly track on a day to day basis. This I think will fit the bill quite nicely. Again thank you VERY much.

[Beege]

Sounds very cool. If your interested in power production theres a nice little low priced hall effect current sensor here you can get for about $7. Works very well for an application such as this. Be sure to let me know if you run into any problems or confusion.

[tom123il]

A bit ago I bought a couple of these RF Link Transmitter - 315MHz. They have a range of 500 ft. Do you think they may work as well?

[Beege]

U mean instead of a wiimote?