Summary of d.i.y. Handheld Multichannel Analyzer (MCA) based on 16F877 PIC Microcontroller and LCD
The article describes a DIY handheld Multichannel Analyzer (MCA) project using a PIC16F877 microcontroller. It features histogramming with 95 channels stored in the microcontroller's variable RAM. The histogram runs until a channel reaches 240 counts, corresponding to an 8-bit max count scaled to the 30-pixel LCD height. The firmware displays a bar spectrum for each channel on the LCD. Additional resources include construction instructions and a schematic for the MCA's front-end.
Parts used in the DIY Handheld Multichannel Analyzer (MCA):
- PIC16F877 Microcontroller
- LCD Display (30-pixel height)
- Variable RAM within the PIC16F877
- Front-end analog circuitry (details in schematic PDF)
Some time ago I was developing a medical instrument which required histogramming, which got me in the mood to retake my own PIC MCA project(http://home.comcast.net/~prutchi/index_files/scint.htm ).
I used the variable RAM in the microcontroller (16F877), so I limited the number of channels to 95 and let the histogram run until some channel reaches 240 counts (the highest 8-bit number that yields an integer when divided by 8 which is also divisible by the 30 pixel height of the LCD).
The firmware then displays the spectrum as a bar with a maximum height of 30 pixels for each one of the 95 channels.
Click here for complete how-to construction instructions in pdf format.
Click here for a pdf of the schematic diagram for the front-end of the MCA
For more detail: d.i.y. Handheld Multichannel Analyzer (MCA) based on 16F877 PIC Microcontroller and LCD
