olkal
commented
2 years ago Hi!
I don't have a testrig for 4 loadcells, but the code looks okay to me. Only thing I notice is that in line 49 you should change <2 to <4 (as you are using 4 loadcells). But I don't think that should couse any problems.
Have you tried to switch the pins around, e.g. change wiring for LoadCell_1 to pin 8 and 9 and wiring for LoadCell_4 to pin 2 and 3? If so, what happens, is there still no change in output from LoadCell_4?
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burgauss
Hello Olkal , thank you for making this library available as I have found it very useful. I am trying to modify the read 2X load cell script , in order to read 4 load cells individually. I added additional pins and calibration values, in line with was has been already done. Nevertheless, I am unable to read correct values for load cells 3 and 4 , i.e. the displayed values don't change when a load is placed on the cell. I checked my wiring and its seems to be fine. Attached is the code, please let me know if you have any suggestions. Thank you !
include
//pins: const int HX711_dout_1 = 2; //mcu > HX711 no 1 dout pin const int HX711_sck_1 = 3; //mcu > HX711 no 1 sck pin const int HX711_dout_2 = 5; //mcu > HX711 no 2 dout pin const int HX711_sck_2 = 4; //mcu > HX711 no 2 sck pin const int HX711_dout_3 = 7; //mcu > HX711 no 3 dout pin const int HX711_sck_3 = 6; //mcu > HX711 no 3 sck pin const int HX711_dout_4 = 9; //mcu > HX711 no 4 dout pin const int HX711_sck_4 = 8; //mcu > HX711 no 4 sck pin
//HX711 constructor (dout pin, sck pin) HX711_ADC LoadCell_1(HX711_dout_1, HX711_sck_1); //HX711 1 HX711_ADC LoadCell_2(HX711_dout_2, HX711_sck_2); //HX711 2 HX711_ADC LoadCell_3(HX711_dout_3, HX711_sck_3); //HX711 3 HX711_ADC LoadCell_4(HX711_dout_4, HX711_sck_4); //HX711 4
//const int calVal_eepromAdress_1 = 0; // eeprom adress for calibration value load cell 1 (4 bytes) //const int calVal_eepromAdress_2 = 4; // eeprom adress for calibration value load cell 2 (4 bytes)
unsigned long t = 0;
void setup() { Serial.begin(57600); delay(10); Serial.println(); Serial.println("Starting...");
float calibrationValue_1; // calibration value load cell 1 float calibrationValue_2; // calibration value load cell 2 float calibrationValue_3; // calibration value load cell 3 float calibrationValue_4; // calibration value load cell 4
calibrationValue_1 = 104.30; // uncomment this if you want to set this value in the sketch calibrationValue_2 = 104.90; // uncomment this if you want to set this value in the sketch calibrationValue_3 = -91.83; // uncomment this if you want to set this value in the sketch calibrationValue_4 = 102.00; // uncomment this if you want to set this value in the sketch
LoadCell_1.begin(); LoadCell_2.begin(); LoadCell_3.begin(); LoadCell_4.begin(); unsigned long stabilizingtime = 2000; // tare preciscion can be improved by adding a few seconds of stabilizing time boolean _tare = true; //set this to false if you don't want tare to be performed in the next step byte loadcell_1_rdy = 0; byte loadcell_2_rdy = 0; byte loadcell_3_rdy = 0; byte loadcell_4_rdy = 0; while ((loadcell_1_rdy + loadcell_2_rdy + loadcell_3_rdy + loadcell_4_rdy) < 2) { //run startup, stabilization and tare, both modules simultaneously if (!loadcell_1_rdy) loadcell_1_rdy = LoadCell_1.startMultiple(stabilizingtime, _tare); if (!loadcell_2_rdy) loadcell_2_rdy = LoadCell_2.startMultiple(stabilizingtime, _tare); if (!loadcell_3_rdy) loadcell_3_rdy = LoadCell_3.startMultiple(stabilizingtime, _tare); if (!loadcell_4_rdy) loadcell_4_rdy = LoadCell_4.startMultiple(stabilizingtime, _tare); } if (LoadCell_1.getTareTimeoutFlag()) { Serial.println("Timeout, check MCU>HX711 no.1 wiring and pin designations"); } if (LoadCell_2.getTareTimeoutFlag()) { Serial.println("Timeout, check MCU>HX711 no.2 wiring and pin designations"); } if (LoadCell_3.getTareTimeoutFlag()) { Serial.println("Timeout, check MCU>HX711 no.3 wiring and pin designations"); } if (LoadCell_4.getTareTimeoutFlag()) { Serial.println("Timeout, check MCU>HX711 no.4 wiring and pin designations"); } LoadCell_1.setCalFactor(calibrationValue_1); // user set calibration value (float) LoadCell_2.setCalFactor(calibrationValue_2); // user set calibration value (float) LoadCell_3.setCalFactor(calibrationValue_3); // user set calibration value (float) LoadCell_4.setCalFactor(calibrationValue_4); // user set calibration value (float) Serial.println("Startup is complete"); }
void loop() { static boolean newDataReady = 0; const int serialPrintInterval = 0; //increase value to slow down serial print activity
// check for new data/start next conversion: if (LoadCell_1.update()) newDataReady = true; LoadCell_2.update(); LoadCell_3.update(); LoadCell_4.update();
//get smoothed value from data set if ((newDataReady)) { if (millis() > t + serialPrintInterval) { float a = LoadCell_1.getData(); float b = LoadCell_2.getData(); float c = LoadCell_3.getData(); float d = LoadCell_4.getData(); Serial.print("Load_cell 1 output val: "); Serial.print(a); Serial.print(" Load_cell 2: "); Serial.print(b); Serial.print(" Load_cell 3: "); Serial.print(c); Serial.print(" Load_cell 4: "); Serial.println(d); newDataReady = 0; t = millis(); } }
// receive command from serial terminal, send 't' to initiate tare operation: if (Serial.available() > 0) { char inByte = Serial.read(); if (inByte == 't') { LoadCell_1.tareNoDelay(); LoadCell_2.tareNoDelay(); LoadCell_3.tareNoDelay(); LoadCell_4.tareNoDelay(); } }
//check if last tare operation is complete if (LoadCell_1.getTareStatus() == true) { Serial.println("Tare load cell 1 complete"); } if (LoadCell_2.getTareStatus() == true) { Serial.println("Tare load cell 2 complete"); } if (LoadCell_3.getTareStatus() == true) { Serial.println("Tare load cell 3 complete"); } if (LoadCell_4.getTareStatus() == true) { Serial.println("Tare load cell 4 complete"); }
}