nRF52840 mini Dongle

RE: nRF52840 mini Dongle

Nguyen Hoan Hoang — Tue, 05 May 2020 22:36:14 GMT

Smaller dongle 100% compatible launching here www.crowdsupply.com/.../blyst840. Also avail in Type-C.

RE: nRF52840 mini Dongle

awneil — Mon, 17 Jun 2019 10:17:08 GMT

[quote userid="2740" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle/193001"]Fanstel USB840M[/quote][quote userid="7735" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle/193029"]they are still quite large[/quote]

The Fanstel USB840M is 26 x 15 x 6 mm

So what is your maximum acceptable size?

[quote userid="2740" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle/193001"]consider how you will initially program or update these dongles[/quote]

at least one of the Fanstel ones has pads for a TagConnect ...

RE: nRF52840 mini Dongle

Ad — Sun, 16 Jun 2019 08:55:37 GMT

Thanks, I checked out the dongles. But they are still quite large.

I did find and buy some nRF52840 dongles from a Chinese company Holyiot (via Alibaba). But thy are also to big.

I did some design myself and even with the nRF52840 in a QFN73 enclosure its possible to create a dongle smaller than 20mm (like the Logitech dongle). And now with the WLCSP package this should be even easier to accomplish. So, I was hoping this small dongle was already on the marked.

The problem with building a small dongle our self is the mechanical tooling cost. And the volume needed by my customer is simply not large enough to cover for that cost.

RE: nRF52840 mini Dongle

Adrian Eggenberger — Sat, 15 Jun 2019 06:57:21 GMT

We had the same discussion internally recently. The dongle from Nordic is a great option if its ok to have a PCB in you hands. For developping purpose it is fine but for customers?

For customers we prefer dongles with a housing. We found the following usb dongles with an nRF52840 in it (I hope its allowed to name products from other companies):

1) Raytac MDBT50Q-RX

2) Fanstel USB840F

3) Fanstel USB840M

Please note that the Fanstel dongles have no 32kHz crystal. You should also consider how you will initially program or update these dongles. As far as i know they all come with a bootloader preinstalled.

If anyone has more dongles I would be interessted to know.

Regards Adrian

RE: nRF52840 mini Dongle

Ad — Fri, 14 Jun 2019 16:38:19 GMT

Hi Andreas,

Thanks for your reply.

And Yes, I know about your dongle. In fact, I own a few of them.

I do like them and thy are great for firmware development. However, for my end customer its way to big. I really need a nice small dongle used in an office environment.

RE: nRF52840 mini Dongle

Andreas — Fri, 14 Jun 2019 13:17:38 GMT

Hi,

Although a bit larger than what you compare to, have you seen our nRF52840 Dongle? https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-Dongle

Best regards,

Andreas

RE: nRF52840 mini Dongle

Ad — Fri, 14 Jun 2019 08:27:55 GMT

[quote userid="6462" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle/192762"]In what way(s) "crappy" ?[/quote]

You have a point here. The appearance of a product is a matter of opinion. So I removed that statement.

[quote userid="6462" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle/192762"]Do you have experience with doing that - especially the RF part?[/quote]

Yes, I have experience with RF design, build FSK and ASK transmitters and receivers from scratch in the past. The RF part of the nRF50840 is not so hard if you follow the reference designs and follow high speed design methodology.

Some tips:

Keep your traces short.
Control the impedance of your tracks @50Ohm.
Make sure the reference plane under your RF traces and parts is not interrupted.
Use bended tracks if possible (no hard corners).
Avoid stubs.
Make sure the self-resonance frequency of your impedance matching parts is as far as possible above 2,5Ghz.
If the design is small. Use a standard chip antenna as described in the reference designs (2450AT18A100E).
Make sure there is no reference plane under the chip antenna.

RE: nRF52840 mini Dongle

awneil — Thu, 13 Jun 2019 15:28:51 GMT

How about posting some links or pictures showing what you want (and, for contrast, what you don't want) ?

And some actual dimensions.

[quote userid="7735" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle"]frankly look a little crappy[/quote]

In what way(s) "crappy" ?

[quote userid="7735" url="~/f/nordic-q-a/48568/nrf52840-mini-dongle"]it is not that difficult to design a dongle[/quote]

Do you have experience with doing that - especially the RF part?