Guidance needed UWB

over the last year I have been working on our product design and implementation,
using the DW3000 on the CDK board to provide distance and AoA to our iPhone app.

this works great, great for Iphone 11-13… but starting with 14, the lack of the second antenna wipes out the AoA info, and we only get distance… … angle is the heart of our design

Apples ‘solution’ is to enable camera assist…

  1. our user is blind… so using camera to scan for something is not possible
  2. camera cannot find our beacon (not line of sight very often, and blends in to background, by design)
  3. camera assist doesn’t work in the dark… we have no control over the implementation locations lighting
  4. camera assist pushes our UI (audio and low vision) to the background… which makes it impossible to control

all these work great on 11-13…

anyhow.,… this leads me to believe we need to make our own end user device to attach to a phone (case) and provide the info from the DW3000 based beacons we have built. (basically replicate the Apple Nearby interaction code)

we don’t have an electrical engineer on our startup team… and are having quite a hard time to get something built on the end beacon side. (my prototypes are all wire connected. )

we currently do not have any code that uses the CDK USB interface, and I would like to use some bluetooth type connection between this add on board and the phone. (which insulates us from cable types, phone types, etc)
I don’t know if I can have my own application code run on the dw3000 on top of the Fira stuff, or if I need ANOTHER processor on board to handle that.

our beacon box has an esp32 providing additional logic, via bluetooth, and I have build flash ota from our config app to update those with our new firmware… but not the cdk board… I can’t do that to the cdk board currently.

I don’t like the idea of my user having to flash the adapter… they are blind…

so, what would it take to breadboard this, driven off rechargable battery with custom firmware to provde the interaction with the fira code… (is that only via USB port on the cdk?)…

any guidance welcomed… and offline discussions possible.

so I have downloaded the lastest sdk and want to use the cli interface.
my cdk was previously flashed with the FREETOS version in the nearby sdk.

so, use jflashlite and flash (erase chip as it was previously flashed with different version) all ok…

now… how do I connect for cli interaction?
the USB cable connected to J9 gets me a ttyACM0 device, but it doesn’t respond on serial port
the USB cable in J20, does NOT provide a serial port…

the docs says J20 is USB/Serial connection.

on mac JFLASH lite said emulator downlevel, but upgrade failed… have to reboot to get back
on linux said emulator downlevel, but went thru, said flashed, but no progress bars.

J20 doesn’t respond on either system
red light is flashing when connected to j20, not flashing when connected to J9.
as expected.

what did I miss? this should have been the easiest part of the tasks.

Hello rexx,
it’s quite interesting to hear that the newer iPhones abandoned one of the antennas, I would have thought it would be more like the other way around but here we are :slight_smile:

I can’t really comment on your reply as I never used the SDK but rather interacted with the DW3000 chip through an ESP32, but what I can comment on is your first leading question.

I’d personally not try to build an adapter board of some sort, as it is (as you already stated) quite unpractical for your users, especially blind ones.

What you could do instead would be to have a two antenna design on the beacon itself to basically get the angle of arrival the other way around and send it as data frames back to the iPhone (I suppose you actually do ranging and don’t only send blink messages from the beacon).
Of course you’d have some sort of compass module on the beacon to provide the right angle, as with rotating the beacon the AoA obviously changes as well, so you’d need to account for that. On the iPhone, you could use the integrated compass to get that data as well without the need of the adapter board.

This of course means that you’d have to redesign your chip but on the other hand means that you don’t have to mess with the clients device in any way.

If you want to setup some custom firmware, you might want to check out my GitHub project on the DW3000 to find some guidance on what to configure. It doesn’t have a second antenna but that’s something that could be added of course.

Let me know if you have any further questions :slight_smile:

Kind regards

thx. the cdk already does the fira ranging application .

the app user wouldn’t know anything about our board, its just a phone case.