Bylund Automotive Support

dgleason wrote: ↑

19 Jun 2019 23:34

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

Yes, no problem. It needs a minimum of 1A so 2A is fine. Just make sure the DC jack is center positive.

I purchased a 12V 2A power supply and tried to plug it into the lambda shield. When the USB is plugged into the arduino, this process goes fine and the LEDs on both boards light up.
If I try to plug in the power supply when the USB is not connected, the LEDs on both boards flash about once/second, but do not stay lit. I am not sure if this is normal behavior of the board.

dgleason wrote: ↑

21 Jun 2019 20:11

If I try to plug in the power supply when the USB is not connected, the LEDs on both boards flash about once/second, but do not stay lit. I am not sure if this is normal behavior of the board.

I can replicate what you are experiencing when I have the X7 jumper and the 12V power supply connected to the Arduino. You should only connect the power supply to the Lambda Shield, not the Arduino.

Please share the output with the Lambda Shield connected like this, and in this order:
1. Connect the lambda sensor. (No power)
2. Connect the jumper cable on X7. (No power)
3. Connect the USB.
4. Connect 12V to the Lambda Shield, not the Arduino.

It should look like this at step 4:


Do you possibly have a multimeter? - It would be very helpful if you could measure the 5V-pin of the Arduino.

My apologies for the inconvenience, let's get to the bottom of this mystery. If we get to a dead end I will send you a complete set of Arduino, shield and sensor so we can eliminate what is causing the wrongful readings.

I plugged in the wires & power in that order and experienced the same issues. I also tried using a different Arduino, with the same results.

Definitely not ruling out the possibility that my power source is the issue. Still using a 12V 2A power source - but the plugs I found were all the wrong size, so I have been using a barrel plug adapter to fit the lambda shield.

I do have a multimeter. What exactly do you want me to measure?

dgleason wrote: ↑

24 Jun 2019 16:11

I plugged in the wires & power in that order and experienced the same issues. I also tried using a different Arduino, with the same results.

And with the same issue do you mean that is reading 1010 ADC in open air or that it is resetting the Arduino and flashing the LED's?

The readings are the same. I only experienced the flashing LED problem when I plug in the power jack but not the arduino.

dgleason wrote: ↑

24 Jun 2019 19:05

The readings are the same. I only experienced the flashing LED problem when I plug in the power jack but not the arduino.

Thank you for clarifying. Using the multimeter, when reading ~1010 during operation could you please measure the voltage between the 5V pin and one of the GND pins on the Arduino? And could you also do the same without the X7 jumper to compare the difference?

Please also let me know your shipping address, send it to christian@bylund-automotive.com and I will ship a replacement Lambda shield for evaluation in parallel. Thank you.

If anyone runs into the same symptom we have concluded that the problem in this case was a faulty oxygen sensor.