I'm trying to make a wire harness tester and my mega freezes when pin 41 is connected to ground. No issues as far as I can tell with any other pins. Tried using a 1.2k resistor in case the internal pullup was shorted or something. I get the first "P" from my serial readout then garbage and it's frozen until I reset it. Running from USB laptop power with no shields or other devices attached.
#define Analog_Read_Port A0
int Pin_Number[40];
int Pin_ADC_Result[40];
int Short_Circuit_Detect = 0;
int sensorValue = 0;
bool Ground_Short = false;
void setup() {
Serial.begin(9600);
// while (!Serial.available());
Serial.println(F("Serial available"));
pinMode(Analog_Read_Port, OUTPUT);
digitalWrite(Analog_Read_Port, LOW);
Serial.println(F("Test probe intialized"));
for (int IP1 = 2; IP1 <= 5; IP1++) {
pinMode(IP1, INPUT_PULLUP);
}
for (int IP2 = 22; IP2 <= 47; IP2++) {
pinMode(IP2, INPUT_PULLUP);
}
}
void loop() {
sensorValue = analogRead(Analog_Read_Port);
delay(1);
if (sensorValue != 0) {
Serial.print(F("A0: "));
Serial.println(sensorValue);
}
memset(Pin_Number, 0, 40);
memset(Pin_ADC_Result, 0, 40);
Short_Circuit_Detect = 0;
for (int p = 2; p <= 5; p++) {
if (digitalRead(p) == LOW) {
Pin_Number[p] = 1;
Short_Circuit_Detect++;
Serial.print(F("Pin "));
Serial.println(p);
Serial.print(F(":"));
}
}
for (int p = 22; p <= 47; p++) {
if (digitalRead(p) == LOW) {
Pin_Number[p] = 1;
Short_Circuit_Detect++;
Serial.print(F("Pin "));
Serial.println(p);
}
}
if (Short_Circuit_Detect > 1) {
Serial.print(F("Short circuit detected across "));
Serial.print(Short_Circuit_Detect);
Serial.println(F(" pins"));
}
}
