From 82563460007b326da6af90eae11a12f0b49730d7 Mon Sep 17 00:00:00 2001
From: Maximilian Friedersdorff <max@friedersdorff.com>
Date: Fri, 1 Jul 2022 21:57:24 +0100
Subject: [PATCH] Work in progress

---
 power_meter.ino | 115 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 power_meter.ino

diff --git a/power_meter.ino b/power_meter.ino
new file mode 100644
index 0000000..d68d0f0
--- /dev/null
+++ b/power_meter.ino
@@ -0,0 +1,115 @@
+#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;
+}
-- 
2.46.2