programming nrf51822 in low voltage mode using level translator

RE: programming nrf51822 in low voltage mode using level translator

monpetit — Wed, 23 Dec 2015 16:41:29 GMT

@michel : Sorry, I don't know either. It seems to rest on experiences.

RE: programming nrf51822 in low voltage mode using level translator

michel — Wed, 23 Dec 2015 14:40:53 GMT

Thank you Stian, I'm thinking on buying another 3rd-Party-Bluetooth-Smart-Module, Which one do you recommend me?

RE: programming nrf51822 in low voltage mode using level translator

michel — Wed, 23 Dec 2015 14:38:39 GMT

Thanks monpetit. Do you know what is the minimum current required?

RE: programming nrf51822 in low voltage mode using level translator

Stian Røed Hafskjold — Wed, 23 Dec 2015 10:59:42 GMT

Use a voltage regulator. See Monpetit's comment.

RE: programming nrf51822 in low voltage mode using level translator

monpetit — Wed, 23 Dec 2015 04:02:41 GMT

Hi michel,

You can replace voltage divider with a regulator such as the MCP1700.

RE: programming nrf51822 in low voltage mode using level translator

michel — Wed, 23 Dec 2015 03:34:14 GMT

I measured the current and I got 0 A... so that is the problem. How can I solve it?

RE: programming nrf51822 in low voltage mode using level translator

michel — Wed, 23 Dec 2015 03:33:58 GMT

I measured the current and I got 0 A... so that is the problem. How can I solve it?

RE: programming nrf51822 in low voltage mode using level translator

michel — Tue, 22 Dec 2015 15:39:06 GMT

Thank you Stian, I'll check as you suggest:

Set SH_VTG to 3.3 V
Set 5kHz in Keil
Check current I'll tell you what happened, no matter what.

RE: programming nrf51822 in low voltage mode using level translator

michel — Tue, 22 Dec 2015 15:32:56 GMT

Thanks for your response, I'll check everything you mention and tell if I find out something.

RE: programming nrf51822 in low voltage mode using level translator

Stian Røed Hafskjold — Tue, 22 Dec 2015 13:01:48 GMT

I'm not able to test the setup since I don't have a logic level translator, but can you try to set SH_VTG to the 3.3V instead of the 1.9V? Since that is the voltage the debugger is seeing.

Are you sure the transistors are able to keep up with the SWD speed? Maybe try to set it to 5kHz in Keil.

And as Monpetit suggested, make sure your voltage divider is able to supply enough current. The chip draws several milliamps while flashing, so make sure the voltage drop is not too high.

Let me know what you find out, and meanwhile I will try to get my hands on a level translator.

RE: programming nrf51822 in low voltage mode using level translator

monpetit — Tue, 22 Dec 2015 12:45:48 GMT

I wonder the reason that you use voltage divider instead of step down regulator. As far as I know the voltage divider can't provide power to other circuitry. Did your board use to work well? Even so, it seems that current of circuitry is not sufficient to be detected by J-Link debugger.

You should check the current to flow into your board.