Problem with external J-Link Interface BMD-350 eval board

RE: Problem with external J-Link Interface BMD-350 eval board

Simonr — Thu, 02 May 2019 12:18:14 GMT

The high frequency clock (32MHz connected to XC1 and XC2) is necessary to make the nRF chip run properly in the first place. The low freq. clock is usually optional, but since the data sheet states that it is required you most likely need that as well. In conclusion, yes, you do need these clocks.

Best regards,

Simon

RE: Problem with external J-Link Interface BMD-350 eval board

SIARI — Thu, 02 May 2019 00:00:37 GMT

Hi Simon,

Are those clocks necessary for the programming specifically? I believe that the datasheet says that both of these clocks can be provided internally. Additionally, when I power my module without connecting to the bmd-350 eval board, I do see a RigCom advertisement, which indicates to me that the module is working. I still can't figure out why I am unable to program the external module with the eval board.

Thanks,

Aritro

RE: Problem with external J-Link Interface BMD-350 eval board

Simonr — Tue, 30 Apr 2019 08:38:11 GMT

Hi Aritro

Have you added the necessary clocks to the BMD-350 module? It is stated in its data sheet (chapter 9.7 Clocks) that the BMD-350 requires two clocks, a high frequency and a low frequency clock that should be connected to XL1/XL2 and XC1/2. Please refer to the data sheet and our reference designs to see what clocks and how they should be placed.

Best regards,

Simon

RE: Problem with external J-Link Interface BMD-350 eval board

SIARI — Tue, 30 Apr 2019 00:06:51 GMT

Hello Simon,

Thank you for your prompt response. I am still stumped about why this is happening as it looks to me like I have connected everything correctly. My only confirmation that the chip on my board is turned on is that when my board is connected to a 3.2V power source, about 20 mA of current is delivered. However this disappears after I proceed to connect the eval board to my computer. Please find my schematic below. Any help is greatly appreciated.

Thanks,

Aritro

RE: Problem with external J-Link Interface BMD-350 eval board

Simonr — Mon, 29 Apr 2019 08:36:59 GMT

Hi Aritro

1. This should not be a problem, as long as those pins are grounded it should work.

2. As long as they are connected correctly and the current goes through, they should work. If you are in doubt, you could always test with thicker wires.

3. In order to program the chip, you have to connect EXT_SWDIO and EXT_SWCLK to SWDIO and SWDCLK on the target BMD. But to run it once programmed, VDD and GND are sufficient to run the chip.

Have you been able to confirm that the chip on the custom board is turned on? I would like to take a look at your schematics, to see that everything is connected properly.

Best regards,

Simon