SEN0641 no data
Raymond82 2025-05-18 05:30:27 336 Views1 Replies I have the SEN0641 connected to a RS485 module on a Arduino mega. On the sensor there is a red light blinking but no data is received.
#define DE_PIN 2
#define RE_PIN 3
const uint8_t SLAVE_ID = 1;
uint16_t calcCRC(const uint8_t *buf, uint8_t len) { /* … Modbus CRC16 … */ }
void setup() {
Serial.begin(9600);
pinMode(DE_PIN, OUTPUT); pinMode(RE_PIN, OUTPUT);
digitalWrite(DE_PIN, LOW); digitalWrite(RE_PIN, HIGH);
Serial1.begin(4800);
delay(100);
}
void loop() {
// Bouw en verzend frame
uint8_t f[] = { SLAVE_ID, 0x03, 0,0, 0,1 };
uint16_t crc = calcCRC(f,6);
digitalWrite(DE_PIN, HIGH);
Serial1.write(f,6); Serial1.write(crc & 0xFF); Serial1.write(crc >> 8);
Serial1.flush();
digitalWrite(DE_PIN, LOW); digitalWrite(RE_PIN, HIGH);
delay(50);
if (Serial1.available()>=7) {
uint8_t r[7]; Serial1.readBytes(r,7);
if (r[0]==SLAVE_ID && r[1]==0x03 && r[2]==0x02) {
uint16_t raw = (r[3]<<8)|r[4];
Serial.print("PAR = "); Serial.println(raw*0.1);
} else Serial.println("Invalid reply");
} else Serial.println("No response");
delay(1000);
}
Raymond82 
