From aad760c0397bf45cfe711fcd3b772c520229a5d1 Mon Sep 17 00:00:00 2001
From: Maximilian Friedersdorff <max@friedersdorff.com>
Date: Thu, 23 Jun 2022 21:08:02 +0100
Subject: [PATCH] Fix unit letters, enable internal pullup resistors

---
 battery_tester.ino | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/battery_tester.ino b/battery_tester.ino
index 9b7865a..3b9b762 100644
--- a/battery_tester.ino
+++ b/battery_tester.ino
@@ -22,8 +22,8 @@ const bool nine[7] = {true, true, true, true, false, true, true};
 const bool zero[7] = {true, true, true, true, true, true, false};
 
 const bool U[7] = {false, true, true, true, true, true, false};
-const bool I[7] = {false, false, true, false, false, false, false};
-const bool P[7] = {true, true, false, false, true, true, true};
+const bool A[7] = {true, true, true, false, true, true, true};
+const bool E[7] = {true, false, false, true, true, true, true};
 
 unsigned char display_state = 0;
 
@@ -76,7 +76,7 @@ void writeDigit(char d, char val, bool dec) {
     }
     for (int i = 0; i < 7; ++i) {
         if (segs[i]) {
-            digitalWrite(segments[i], HIGH);      
+            digitalWrite(segments[i], HIGH);
         } else {
             digitalWrite(segments[i], LOW);
         }
@@ -118,12 +118,13 @@ void showVoltage(float volts) {
     writeDigit(2, cvolts % 10, false);
     writeLetter(3, U);
 }
+
 void showCurrent(float current) {
     int camp = current * 100;
     writeDigit(0, (camp/100U) % 10, true);
     writeDigit(1, (camp/10U) % 10, false);
     writeDigit(2, camp % 10, false);
-    writeLetter(3, I);
+    writeLetter(3, A);
 }
 
 void showWh(float watthours) {
@@ -131,7 +132,7 @@ void showWh(float watthours) {
   writeDigit(0, (w/1000U) % 10, true);
   writeDigit(1, (w/100U) % 10, false);
   writeDigit(2, (w/10U) % 10, false);
-  writeLetter(3, P);
+  writeLetter(3, E);
 }
 
 
@@ -152,9 +153,9 @@ void setup() {
     pinMode(15, OUTPUT);
     digitalWrite(15, LOW);
 
-    pinMode(19, INPUT);
-    pinMode(20, INPUT);
-    pinMode(21, INPUT);
+    pinMode(19, INPUT_PULLUP);
+    pinMode(20, INPUT_PULLUP);
+    pinMode(21, INPUT_PULLUP);
 }
 
 void loop() {
-- 
2.46.2