How to support more tags on one iPhone by adjusting the sampling frequency based on the iOS sample code/firmware of DWM3001CDK?

I recently bought several DWM3001CDKs and measured the distance between 6 qorvo modules and an iPhone based on the provided firmware and iOS code.
However, more than 6 qorvo modules are not connected. I looked at the iOS code, but couldn’t find the part about the maximum number of supported models, so I’m guessing the sampling frequency is the cause.

Is it correct to solve the limitation of the number of connectable modules by modifying the sampling rate on the module side?

Is there a way to modify only the sampling rate without directly modifying the firmware?

I’ve been reading “DWM3001CDK Quick Start Guide.pdf”, “DWM3001CDK_SDK_Developer_Guide_0.1.1.pdf”, etc. to change the firmware, but I’m getting lost. Can you elaborate a bit more on this part?

Hi @K-tomato !

The Apple NI API is closed with almost no room for change. Since six devices seems like a low number for both BLE and UWB, the limitation on the number of devices should be something else like how iOS handles NI Sessions and how many resources they allow the NI API to use within iOS, but I I don’t have that information, I’m just speculating.

With the release of iOS 16, background mode was introduced. Background mode seems to use less resources than regular NI (no direction, lower TWR rate), it might be worth testing if you can connect more devices using this mode, if it suits your application.

Best regards!

1 Like

doah, I only ordered 6 cdk boards… but we know there will be more… this would impact us as well…

1 Like

I have the opportunity to test not only the iPhone 12 that I’ve been using, but also the iPhone 12 mini, iPhone 13, and iPhone 14 Pro. However, the maximum number of devices that can be connected on all devices was the same, which was six. The iOS versions of the test devices were 16.3.1 and 16.4.1. I’m trying to solve this problem by using the pause() function of iOS nearby interaction.

In addition, the default firmware of the DWM3001CDK provided by Qorvo for connecting to the iPhone does not support connection with more than two iPhones. Once you start connecting to one iPhone, you can’t even search for Bluetooth signals from other iPhones, and if you try to connect simultaneously, only one of the two iPhones will be connected, and the remaining iPhone can only be connected after the first iPhone’s connection is terminated. Since Qorvo’s product description states that one DWM3001CDK module can be connected to multiple APs, I am trying to modify the firmware to solve this problem.

I’m sorry to deliver the bad news.
The maximum number of devicesin iPhone 14 Pro that can be connected on all devices was the same, which was six.

DWM3001CDK module can be connected to multiple APPs

I think that is using the CDK as the BT client (request connect) , not the peripheral. (accept request)

thanks. I saw your prior message, I think in our scenario we can selectively scan, so that we don’t consume all the UWB devices by one phone…

haven’t tried it yet, as my dev environment hit the wall today… iphone upgraded to 16.4.1, which requires xcode 13 which requires ventura which won’t run on my mac mini 2014… SO… gotta go get a new mac…