Russell Shomberg / Mbed 2 deprecated shomberg_hw_5

7 Segment display for tm36 temperature sensor

Dependencies:   mbed

Fork of shomberg_hw_4 by Russell Shomberg

main.cpp@6:8cfa0216554f, 2018-10-16 (annotated)

Committer:
rshomberg
Date:
Tue Oct 16 14:52:21 2018 +0000
Revision:
6:8cfa0216554f
Parent:
5:dbd163551a58
Child:
7:1a43ff8ccc08
finished

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rshomberg 0:82635173a413 1 /**
rshomberg 6:8cfa0216554f 2 Temperature Sensor
rshomberg 0:82635173a413 3 main.cpp
rshomberg 0:82635173a413 4
rshomberg 6:8cfa0216554f 5 Purpose: Read signal from TMP36 connected to pin20
rshomberg 6:8cfa0216554f 6 Display output voltage to terminal
rshomberg 6:8cfa0216554f 7 Display difference in mV of output voltage to starting voltage on 2x 7-Segment Displays
rshomberg 6:8cfa0216554f 8 See outputs for pin configuration
rshomberg 6:8cfa0216554f 9 Toggle switch connected to pin07 to convert displays to degC
rshomberg 6:8cfa0216554f 10
rshomberg 0:82635173a413 11 @author Russell Shomberg
rshomberg 6:8cfa0216554f 12 @version 1.0 2018-10-15
rshomberg 0:82635173a413 13
rshomberg 6:8cfa0216554f 14 Issues: No Decimal point for temperature
rshomberg 0:82635173a413 15
rshomberg 5:dbd163551a58 16 */
rshomberg 0:82635173a413 17
rshomberg 0:82635173a413 18 // INCLUDES
rshomberg 0:82635173a413 19 #include "mbed.h"
rshomberg 0:82635173a413 20
rshomberg 0:82635173a413 21 // INPUTS
rshomberg 2:312a0a9c4485 22 DigitalIn switchPosition(p7); // wire p7 to middle connection of 2 position switch between Vref and GND
rshomberg 2:312a0a9c4485 23 AnalogIn Ain(p20); // wire p20 to a variable resister connected from Vref and GND
rshomberg 0:82635173a413 24
rshomberg 0:82635173a413 25 // OUTPUTS
rshomberg 2:312a0a9c4485 26 Serial pc(USBTX, USBRX); // for debugging
rshomberg 6:8cfa0216554f 27
rshomberg 6:8cfa0216554f 28 //// Pin Map for 7-Seg starts bottom left, goes CCW
rshomberg 6:8cfa0216554f 29 BusOut Seg1(p12,p13,p14,p15,p16,p17,p18,p19); //01 02 03 04 05 06 07 08 09 10
rshomberg 6:8cfa0216554f 30 BusOut Seg2(p21,p22,p23,p24,p25,p26,p27,p28); //E D CC C DP B A CC F G
rshomberg 6:8cfa0216554f 31
rshomberg 6:8cfa0216554f 32 // FUNCTIONS
rshomberg 6:8cfa0216554f 33 char SegConvert(int SegValue);
rshomberg 0:82635173a413 34
rshomberg 0:82635173a413 35 // VARIABLES
rshomberg 6:8cfa0216554f 36 int outputT= 0;
rshomberg 6:8cfa0216554f 37 float v0;
rshomberg 6:8cfa0216554f 38 float deltav;
rshomberg 6:8cfa0216554f 39 float temp0;
rshomberg 6:8cfa0216554f 40 float deltatemp;
rshomberg 6:8cfa0216554f 41 float val;
rshomberg 6:8cfa0216554f 42 int ones;
rshomberg 6:8cfa0216554f 43 int tens;
rshomberg 6:8cfa0216554f 44
rshomberg 0:82635173a413 45
rshomberg 0:82635173a413 46 int main() {
rshomberg 6:8cfa0216554f 47 // read starting voltage from temperature sensor
rshomberg 6:8cfa0216554f 48 v0 = Ain*3.5*1000;
rshomberg 6:8cfa0216554f 49
rshomberg 0:82635173a413 50 while(1) {
rshomberg 6:8cfa0216554f 51 // Read Switch if on output temp else output mV
rshomberg 6:8cfa0216554f 52 outputT = switchPosition;
rshomberg 6:8cfa0216554f 53
rshomberg 6:8cfa0216554f 54 // Read temperature sensor
rshomberg 6:8cfa0216554f 55 deltav = Ain*3.5*1000-v0;
rshomberg 1:cbee04784c60 56
rshomberg 6:8cfa0216554f 57 // Output to terminal
rshomberg 6:8cfa0216554f 58 if (outputT) {
rshomberg 6:8cfa0216554f 59 // Convert to temp
rshomberg 6:8cfa0216554f 60 deltatemp = deltav/10;
rshomberg 6:8cfa0216554f 61 printf("Temperature Difference = %1.2f degC\n\r", deltatemp);
rshomberg 6:8cfa0216554f 62 val = deltatemp;
rshomberg 6:8cfa0216554f 63 }
rshomberg 6:8cfa0216554f 64
rshomberg 6:8cfa0216554f 65 else {
rshomberg 6:8cfa0216554f 66 printf("Voltage Difference = %1.2f mV\n\r", deltav);
rshomberg 6:8cfa0216554f 67 val = deltav;
rshomberg 6:8cfa0216554f 68 }
rshomberg 4:098e3d869055 69
rshomberg 6:8cfa0216554f 70 // Convert val to ones and tens char
rshomberg 6:8cfa0216554f 71 ones = fmod(rint(val),10);
rshomberg 6:8cfa0216554f 72 tens = fmod(rint(val) / 10, 10);
rshomberg 1:cbee04784c60 73
rshomberg 6:8cfa0216554f 74
rshomberg 6:8cfa0216554f 75 Seg1 = ~SegConvert(ones);
rshomberg 6:8cfa0216554f 76 Seg2 = ~SegConvert(tens);
rshomberg 6:8cfa0216554f 77
rshomberg 6:8cfa0216554f 78
rshomberg 6:8cfa0216554f 79 wait(1);
rshomberg 6:8cfa0216554f 80
rshomberg 0:82635173a413 81 }
rshomberg 6:8cfa0216554f 82
rshomberg 0:82635173a413 83 }
rshomberg 6:8cfa0216554f 84
rshomberg 6:8cfa0216554f 85
rshomberg 6:8cfa0216554f 86 //ones: 12 13 14 15 16 17 18 19
rshomberg 6:8cfa0216554f 87 // A B C D E F G P
rshomberg 6:8cfa0216554f 88 //tens: 21 22 23 24 25 26 27 28
rshomberg 6:8cfa0216554f 89 //
rshomberg 6:8cfa0216554f 90
rshomberg 6:8cfa0216554f 91 char SegConvert(int SegValue) { // function 'SegConvert'
rshomberg 6:8cfa0216554f 92 char SegByte=0x00;
rshomberg 6:8cfa0216554f 93 switch (abs(SegValue)) { // ABCDEFGP
rshomberg 6:8cfa0216554f 94 case 0 : SegByte= 0x3F;break; // 11111100 binary
rshomberg 6:8cfa0216554f 95 case 1 : SegByte= 0x06;break; // 01100000 binary
rshomberg 6:8cfa0216554f 96 case 2 : SegByte= 0x5B;break; // 11110110 binary
rshomberg 6:8cfa0216554f 97 case 3 : SegByte= 0x4F;break; // 10011110 binary
rshomberg 6:8cfa0216554f 98 case 4 : SegByte= 0x66;break; // 11001100 binary
rshomberg 6:8cfa0216554f 99 case 5 : SegByte= 0x6D;break; // 11011010 binary
rshomberg 6:8cfa0216554f 100 case 6 : SegByte= 0x7D;break; // 11111010 binary
rshomberg 6:8cfa0216554f 101 case 7 : SegByte= 0x07;break; // 00001110 binary
rshomberg 6:8cfa0216554f 102 case 8 : SegByte= 0x7F;break; // 11111110 binary
rshomberg 6:8cfa0216554f 103 case 9 : SegByte= 0x6F;break; // 11011110 binary
rshomberg 6:8cfa0216554f 104 }
rshomberg 6:8cfa0216554f 105 return SegByte;
rshomberg 6:8cfa0216554f 106 }