--- /dev/null
+#include <LightChrono.h>
+#include <Chrono.h>
+
+const int digits[] = {9, 10, 11, 12};
+const int segments[] = {2, 8, 4, 5, 6, 7, 3};
+
+const bool one[7] = {false, true, true, false, false, false, false};
+const bool two[7] = {true, true, false, true, true, false, true};
+const bool three[7] = {true, true, true, true, false, false, true};
+const bool four[7] = {false, true, true, false, false, true, true};
+const bool five[7] = {true, false, true, true, false, true, true};
+const bool six[7] = {true, false, true, true, true, true, true};
+const bool seven[7] = {true, true, true, false, false, false, false};
+const bool eight[7] = {true, true, true, true, true, true, true};
+const bool nine[7] = {true, true, true, true, false, true, true};
+const bool zero[7] = {true, true, true, true, true, true, false};
+
+Chrono timer;
+
+float photosensor_voltage = 0;
+
+
+void writeDigit(char d, char val, bool dec) {
+ const bool *segs;
+ switch (val) {
+ case 0:
+ segs = zero;
+ break;
+ case 1:
+ segs = one;
+ break;
+ case 2:
+ segs = two;
+ break;
+ case 3:
+ segs = three;
+ break;
+ case 4:
+ segs = four;
+ break;
+ case 5:
+ segs = five;
+ break;
+ case 6:
+ segs = six;
+ break;
+ case 7:
+ segs = seven;
+ break;
+ case 8:
+ segs = eight;
+ break;
+ case 9:
+ segs = nine;
+ break;
+ }
+ for (int i = 0; i < 7; ++i) {
+ if (segs[i]) {
+ digitalWrite(segments[i], HIGH);
+ } else {
+ digitalWrite(segments[i], LOW);
+ }
+ }
+ if (dec) {
+ digitalWrite(segments[7], HIGH);
+ }
+ digitalWrite(digits[d], LOW);
+ delay(1);
+ digitalWrite(digits[d], HIGH);
+ digitalWrite(segments[7], LOW);
+}
+
+void showNumber(float number) {
+ int n = number;
+ writeDigit(0, (n/1000U) % 10, false);
+ writeDigit(1, (n/100U) % 10, false);
+ writeDigit(2, (n/10U) % 10, false);
+ writeDigit(3, n % 10, false);
+}
+
+void setup() {
+ // put your setup code here, to run once:
+ Serial.begin(9600);
+
+ for (int i = 0; i < 4; ++i) {
+ pinMode(digits[i], OUTPUT);
+ digitalWrite(digits[i], HIGH);
+ }
+ for (int i = 0; i < 7; ++i) {
+ pinMode(segments[i], OUTPUT);
+ digitalWrite(segments[i], LOW);
+ }
+}
+
+void loop() {
+ if (timer.hasPassed(100)) {
+ timer.restart();
+ photosensor_voltage = readMinVoltage(A5);
+ }
+ showNumber(photosensor_voltage);
+
+}
+
+float readMinVoltage(int pin) {
+ float minvolts = 5000;
+ float volts = 0;
+ for (int i = 0; i < 100; ++i) {
+ volts = analogRead(A7) * (4.8/1.023);
+ if (volts < minvolts) {
+ minvolts = volts;
+ }
+ delay(0.2);
+ }
+ return minvolts;
+}