Lambda GUI not reading

[dgleason]

I've added the jumper wire. The readings have not changed - the GUI outputs 20.95%, and the serial monitor output looks similar to before: STATUS,2,10495,1010,178,733
Still not getting useful readings.

[dgleason]

The problem also occurs regardless of which port the 12v supply is plugged into - I've tried to plug into each the Arduino and the lambda shield (one at a time!), and the output looks the same.

[Christian_Bylund]

I've added the jumper wire. The readings have not changed - the GUI outputs 20.95%, and the serial monitor output looks similar to before: STATUS,2,10495,1010,178,733
Still not getting useful readings.

Thank you for the data, it is helpful. Let us analyse your readings:
2 = Heater is in temperature regulation. OK
10495 = The CJ125 outputs no error 0x28FF in hex. OK.
1010 = If in open air we are expecting a value around 854 and typically below that. We are minimum 18% too high. NOK
178 = This is the actual value of the temperature regulation, 178 is normal so we can assume the sensors temperature is OK.
733 = Supply voltage, approximately 10.8V. Nothing unusual for a 12V-1A power supply under load. OK

1. Are these readings in open air with nothing influencing the oxygen sensor?
2. Could you share any information on where you acquired the oxygen sensor?
3. Is it possible that you could share a picture of the set up?

The problem also occurs regardless of which port the 12v supply is plugged into - I've tried to plug into each the Arduino and the lambda shield (one at a time!), and the output looks the same.

Yes there is no difference, you can use any but I recommend you to use the one on the Lambda Shield as it is designed to cope with the currents. The Arduino is not which is why we added a separate DC-jack.

[dgleason]

The O2 sensor is in normal, open air, not obstructed, etc. It was purchased from this website along with the lambda board.

[Christian_Bylund]

The O2 sensor is in normal, open air, not obstructed, etc. It was purchased from this website along with the lambda board.

Very helpful, thank you for your patience. Please help me also with the following information.

1. The serial output from the example code with the set up shown in the picture. https://raw.githubusercontent.com/Bylund/Lambda-Shield-Example/master/Lambda_Shield_Example.ino

2. The serial output from the following code to evaluate the ADC on the Arduino. Run the code with the 3.3V pin connected to A5 as such:

Code: Select all

//Define pin assignments.
#define UC_ANALOG_INPUT_PIN 5 /* Analog input for ADC calibration 3.3V */

//Function to set up device for operation.
void setup() {
  
  //Set up serial communication.
  Serial.begin(9600);

  //Read 3.3V ADC Value (674 ± 2) .
  int adcValue_UC = analogRead(UC_ANALOG_INPUT_PIN);

  if (adcValue_UC >= 672 && adcValue_UC <= 676) {
    Serial.print("[PASS]\t3.3V Calibration Test.\t\t\t(");
    Serial.print(adcValue_UC, DEC);
    Serial.print(")\n\r");
  } else {
    Serial.print("[FAIL]\tADC Calibration Test.\t\t\t(");
    Serial.print(adcValue_UC, DEC);
    Serial.print(")\n\r");
  }
}

//Infinite loop.
void loop() {

}

[dgleason]

1. Using the code linked, this is the serial output:
Measuring, CJ125: 0x28FF, UA_ADC: 1010, UR_ADC: 179, UBat_ADC: 732, Lambda: -, Oxygen: 20.95%
Measuring, CJ125: 0x28FF, UA_ADC: 1011, UR_ADC: 178, UBat_ADC: 735, Lambda: -, Oxygen: 20.95%
Measuring, CJ125: 0x28FF, UA_ADC: 1011, UR_ADC: 179, UBat_ADC: 772, Lambda: -, Oxygen: 20.95%

2.With the setup and code provided:
[PASS] 3.3V Calibration Test. (673)

Thank you so much for your help so far.

[Christian_Bylund]

1. Using the code linked, this is the serial output:
Measuring, CJ125: 0x28FF, UA_ADC: 1010, UR_ADC: 179, UBat_ADC: 732, Lambda: -, Oxygen: 20.95%
Measuring, CJ125: 0x28FF, UA_ADC: 1011, UR_ADC: 178, UBat_ADC: 735, Lambda: -, Oxygen: 20.95%
Measuring, CJ125: 0x28FF, UA_ADC: 1011, UR_ADC: 179, UBat_ADC: 772, Lambda: -, Oxygen: 20.95%

Thank you. Could you please also post the calibration data, it should look something like this:
UA_Optimal (λ = 1.00): 305 (λ = 1.00)
UR_Optimal: 176

[dgleason]

UA_Optimal (λ = 1.00): 304 (λ = 1.00)

UR_Optimal: 176

I'm concerned that the power source could be part of the problem. I'm using a 12V, 1A wall plug. However, it takes multiple tries of plugging the jack into the board, and removing and replacing the jumper wire before the LEDs on both the Arduino and Lamda shield light up.

[Christian_Bylund]

UA_Optimal (λ = 1.00): 304 (λ = 1.00)
UR_Optimal: 176

These values are spot on, thank you.

I'm concerned that the power source could be part of the problem. I'm using a 12V, 1A wall plug. However, it takes multiple tries of plugging the jack into the board, and removing and replacing the jumper wire before the LEDs on both the Arduino and Lamda shield light up.

That is definitely not a normal behaviour. Is it possible for you to try another 12V power source, minimum 1A? - Just to remove the doubt. Plug it in to the Lambda Shield with the jumper wire and USB already connected. It could be that we have a problem with the power supply under load.

[dgleason]

Can the board handle 2A? If so, I'll try a higher current power supply.