My BTS7960 Motor Driver's M+ M- gates don't have voltage output

Other Hardware General Electronics
1

Hi, this is my first assignment in college. My task was to create a prototype for Thermotherapy, so I chose a Peltier Module Tec1-12710 for both heating and cooling. I used a BTS7960 to control the Peltier and reverse the current with an H-Bridge. Unfortunately, when I check with the Voltage meter, the Voltage at M+ M- gates is approximately 0V. I tried with no Motor and the result is still the same. Am I wiring it wrong, or is my BTS7960 damaged? B+ B- got supplied from 12V10A DC, R_EN and L_EN and R_PWM and L_PWM pins are included in the code, R_IS and L_IS are connected to the 5V pin of the Arduino UNO R3. As a new member, I can't post the datasheet of BTS7960 and TEC1-12710, but they are the generic ones, with no change or any modifications. The code is below

const int R_EN = 8;
const int L_EN = 7;
const int RPWM = 5;
const int LPWM = 6;

void setup() {
  Serial.begin(9600);

  // Set all control pins as outputs
  pinMode(R_EN, OUTPUT);
  pinMode(L_EN, OUTPUT);
  pinMode(RPWM, OUTPUT);
  pinMode(LPWM, OUTPUT);

  // Enable both sides of the H-bridge
  digitalWrite(R_EN, HIGH);
  digitalWrite(L_EN, HIGH);

  Serial.println("BTS7960 + Peltier test starting...");
}

void loop() {
  // Cooling mode: M+ high, M− low
  analogWrite(RPWM, 255);  // Full speed
  analogWrite(LPWM, 0);
  Serial.println("Cooling mode: RPWM = 255, LPWM = 0");
  delay(5000);

  // Stop Peltier
  analogWrite(RPWM, 0);
  analogWrite(LPWM, 0);
  Serial.println("Peltier off");
  delay(2000);

  // Heating mode: M− high, M+ low (reverse)
  analogWrite(RPWM, 0);
  analogWrite(LPWM, 255);  // Full speed reverse
  Serial.println("Heating mode: RPWM = 0, LPWM = 255");
  delay(5000);

  // Stop again
  analogWrite(RPWM, 0);
  analogWrite(LPWM, 0);
  Serial.println("Peltier off");
  delay(2000);
}
2

R_IS and L_IS are current sense outputs, not input pins. Connecting them to 5V can damage the board or cause it to not operate. They should be either left unconnected if you don’t need current sensing, or connected to analog input pins of the Arduino if you're reading current.

3

Hi, sorry for the slow reply. I didn't know about the R_IS and L_IS, thanks for the correction. About the M+ and M- gates, do you think it already harmed the module?

4

That is clearly spelled out in the data sheet. Posting an annotated schematic will help us help you.