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OBD-II UART Adapter V1 power consumption
Posted: Thu Jan 06, 2022 6:28 pm
by rado
Hello,
I recently bought an OBD-II UART Adapter V1 and I succesfully reading data with my code and device. I would like to leave it in a car even I am not using it, so I tried to focus on power consumption and send a "ATLP" command. But the consumption is about
12mA. According to your pages (
https://freematics.com/store/index.php? ... duct_id=30) it should 5mA in low power mode!
I also tried to find some other AT commands in ELM327's datasheet, but i couldn't find anything.
Am I missing something? Can someone point me to some solution?
Thank you!
Rado
Re: OBD-II UART Adapter V1 power consumption
Posted: Fri Jan 21, 2022 8:35 pm
by stanley
How did you measure the load?
Re: OBD-II UART Adapter V1 power consumption
Posted: Sat Jan 22, 2022 12:55 am
by rado
I use a laboratory power supply set to 12V. I have a multimeter in series on the positive wire as you can see on attached photo.
Meanwhile, I tried other 4 adapters and I find out that's probably issue of this one.
(The adapter is just connected to an UART<->USB adapter)
Is there something what should I try to do to solve it?
Re: OBD-II UART Adapter V1 power consumption
Posted: Sat Jan 22, 2022 8:34 pm
by stanley
You may need to consider the load of the connected dev board.
Re: OBD-II UART Adapter V1 power consumption
Posted: Mon Jan 24, 2022 7:30 pm
by rado
Connected board on the photo is just UART-USB convertor (ftdi232). It has power from laptop.
There is only RX,TX and GND wire connected.
Re: OBD-II UART Adapter V1 power consumption
Posted: Tue Jan 25, 2022 8:47 pm
by stanley
Current might still flow through Tx pin. Could you test with the board disconnected? Even without ATLP command sent, the adapter will enter sleep mode without OBD and serial UART activity for 30 seconds.
Re: OBD-II UART Adapter V1 power consumption
Posted: Thu Jan 27, 2022 7:51 pm
by rado
There is probably small current but I tested it without convertor and the result is on the attached photos. It's even worse
After I pluged the convertor it woke up and after 30 s the current fell down to 12.4 mA.
It's really strange behavior.
Re: OBD-II UART Adapter V1 power consumption
Posted: Thu Jan 27, 2022 9:50 pm
by stanley
Seems there is little difference. What about removing the meter and switch your power supply's current display to mA?
Re: OBD-II UART Adapter V1 power consumption
Posted: Fri Mar 18, 2022 11:12 pm
by rado
Sorry for not responding a longer time.
It doesn't have any impact, current is on the same level. I also open the adapter to check circuit board and everything seems fine to me. Maybe there is some hidden problem.
Currently i don't have more time to investigate the cause. We have other properly working adapters so we use them.
Thank you for your help!