1 #include <LightChrono.h>
4 const float APPARENT_SHUNT_RESISTANCE = 0.453;
5 const float VOLTAGE_REFERENCE = 2.489;
10 const int digits[] = {2, 3, 4, 5};
11 const int segments[] = {6, 7, 8, 9, 10, 11, 12, 13};
13 const bool one[7] = {false, true, true, false, false, false, false};
14 const bool two[7] = {true, true, false, true, true, false, true};
15 const bool three[7] = {true, true, true, true, false, false, true};
16 const bool four[7] = {false, true, true, false, false, true, true};
17 const bool five[7] = {true, false, true, true, false, true, true};
18 const bool six[7] = {true, false, true, true, true, true, true};
19 const bool seven[7] = {true, true, true, false, false, false, false};
20 const bool eight[7] = {true, true, true, true, true, true, true};
21 const bool nine[7] = {true, true, true, true, false, true, true};
22 const bool zero[7] = {true, true, true, true, true, true, false};
27 void writeDigit(char d, char val) {
61 for (int i = 0; i < 7; ++i) {
63 digitalWrite(segments[i], HIGH);
65 digitalWrite(segments[i], LOW);
68 digitalWrite(digits[d], LOW);
70 digitalWrite(digits[d], HIGH);
73 void showNumber(float number) {
75 writeDigit(0, (n/1000U) % 10);
76 writeDigit(1, (n/100U) % 10);
77 writeDigit(2, (n/10U) % 10);
78 writeDigit(3, n % 10);
83 // put your setup code here, to run once:
85 analogReference(EXTERNAL);
87 for (int i = 0; i < 4; ++i) {
88 pinMode(digits[i], OUTPUT);
89 digitalWrite(digits[i], HIGH);
91 for (int i = 0; i < 8; ++i) {
92 pinMode(segments[i], OUTPUT);
93 digitalWrite(segments[i], LOW);
100 float battery_voltage;
101 float amps_in_period;
102 float watts_in_period;
106 if (timer.hasPassed(1000)) {
107 unsigned long passed = timer.elapsed();
110 shunt_voltage = readVoltage(A1);
111 shunt_current = shunt_voltage/APPARENT_SHUNT_RESISTANCE;
113 battery_voltage = readVoltage(A0);
115 amps_in_period = shunt_current * passed/1000;
116 watts_in_period = amps_in_period * battery_voltage;
118 ampseconds += amps_in_period;
119 wattseconds += watts_in_period;
120 mamphours = ampseconds/3.6;
121 mwatthours = wattseconds/3.6;
123 if (battery_voltage < 0.8) {
127 showNumber(mamphours);
130 float readVoltage(int pin) {
133 for (int i = 0; i < 4; ++i) {
134 val = val + analogRead(pin);
138 return (val / 4) * VOLTAGE_REFERENCE/1023.0;