eee305 microcontroller systems lecture 8: analogue to digital conversion using pic microcontrollers...
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EEE305 Microcontroller Systems
Lecture 8: Analogue to Digital Conversion using PIC microcontrollers and the C compiler
(NB As of 18/04/13 this code uses the older HTC compiler, I will change it to the more modern XC8 compiler in class)
Teaching resources are at www.eej.ulst.ac.uk
My office 5B18, telephone 028 90 366364My email IJ.McCrum@ulster.ac.uk
http://www.eej.ulst.ac.uk/~ian/modules/EEE305 1/
Datasheet Chapter 11
C Code to read ADC and O/p reading
Last week’s code to use USART serial port
Main code to test ADC
Further experiments
• If the ADC returns a number from 0 to 1024• Scale this to 80 (the width of a PUTTY screen)• Use a for loop
For(i=0;i<scaled_reading;i++){putchar(‘*’);} Printf(“\r\n”);
• This will print a “graph” across the screen.
Making a Thermometer• Assume the thermistor initially reads 20 degrees • After holding for 60 seconds assume it reads 35 degrees• Scale the readings to display degrees• i.e If you get a reading of XX for 20 degrees and YY for 35
degrees.
20⁰C
35⁰C
XX YYZZ
??⁰C
Don’t forget to use variables of type float if they are needed
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