No connection when using the DC/DC converter

RE: No connection when using the DC/DC converter

Arne Laugstøl — Mon, 29 Jan 2018 07:19:28 GMT

Thanks for answer Jørgen. I also find it quit possible that it is the Engineering B samples that has problems regarding DCDC. We will produce a small batch with revision 1/2, and see if that solves the problem.

RE: No connection when using the DC/DC converter

Jørgen Holmefjord — Fri, 26 Jan 2018 15:11:40 GMT

As you can see from the compatibility matrix, QFAABA is Engineering B revision of the chip, while QFABB0 is revision 1 chip. I would advise against using the engineering revisions of the chip, as this have a long errata list. With regards to DCDC, this errata might cause some issue. The DCDC will be on at all times, which can increase the noise and cause connection issues. Please try switching to revision 1/2 chips and see if this solve the issue.

RE: No connection when using the DC/DC converter

Arne Laugstøl — Fri, 26 Jan 2018 14:41:41 GMT

Hi Jørgen We took a closer look at what kind of chips we got from the different suppliers, adn we discovered a difference. We got QFAABA (1545AG) from PCBWay and we got QFABB0 (1712AM) from Eurocircit.

Should that make a difference in how the DC/DC is handled?

I have also uploaded the scmeatics and the BOM list on my page. Regards Arne

RE: No connection when using the DC/DC converter

Jørgen Holmefjord — Fri, 26 Jan 2018 14:04:23 GMT

It is hard to say what could be causing this, as the boards fabricated from the same files should be identical. As you say, the DCDC components would be the first suspects, but some other things that could affect the performance of the board is:

Soldering or etching process could cause short between pins, or components that is not soldered to its pad
Noise from DCDC causing RADIO RX issues
Wrong/different component/value. Which revision is the nRF chip, and is this the same on both boards?

Could you upload the production files (schematics/layout/BOM) for a review? If you do not want to share it in public, you can create a new case on MyPage and link to this thread.

RE: No connection when using the DC/DC converter

Arne Laugstøl — Tue, 23 Jan 2018 07:54:50 GMT

To my understanding, there has to be a hardware difference between the two types of card. (Probably some wrong components). Could someone point me in the right direction, which component is likly to give such a problem (other than the 2 inductors and the capasitor surronding the DC_DC converter)

RE: No connection when using the DC/DC converter

Arne Laugstøl — Tue, 23 Jan 2018 07:51:07 GMT

Hi Jørgen I have tried setting DEBUG flag. And there is no problem when I run with the debugger. After I have run without the debugger, and experience that it will not connect, then the debugger resets the device when I plug in the debugger. So, then all information is lost.

RE: No connection when using the DC/DC converter

Jørgen Holmefjord — Fri, 19 Jan 2018 16:24:01 GMT

Have you tried setting the DEBUG flag, to see if the device gets an error code and ends up in the error handler? The default recovery method is to reset the chip, which can make it look like the connection is never happening and advertising continues if this is the default behavior on startup.

RE: No connection when using the DC/DC converter

Arne Laugstøl — Thu, 18 Jan 2018 14:26:58 GMT

I am using Segger j-Link as a debugger. When I try to connect, the board continue to advertise. I have not tested with GPIO/LED. But, I have tried to use sniffer and Wire-Shark, and it seems that the board doesn't try connect, it just continue to advertise.

RE: No connection when using the DC/DC converter

Jørgen Holmefjord — Thu, 18 Jan 2018 12:19:36 GMT

What are you using for connecting the the device? Do you get any error codes? Does the board reset, or just lock when you try to connect? Have you tested with some serial/GPIO/LED debugging to see where the application fails?

RE: No connection when using the DC/DC converter

Arne Laugstøl — Thu, 18 Jan 2018 11:25:20 GMT

The strange thing is that if I am using a debugger, then it works fine (even the PCBWay). Without a debugger it works fine until I try to connect from my phone. It is advertising as expected, but no connection.

RE: No connection when using the DC/DC converter

Andre — Thu, 18 Jan 2018 09:25:28 GMT

When you connect a debugger, is the code still running after you enter DCDC mode, or does it hang? Does the entire board die, or just the radio?