ESB maximum number of pipes

[Enrico V.]

Hello,

I am evaluating the possibility to use ESB protocol on nRF52840 development kit. As far as I understood, for HW limitations, the maximum number of pipes in a star network configuration is 8. Unfortunately, for my application I need to connect up to 20 transmitters to a receiver. I have seen in this ticket that there is the possibility to increase the maximum number of pipes but it is not clear to me how to proceed.

Can you please give me some more details? In case, is there any example available?

Thank you in advance.

Best regards,

Enrico  

[Cedric Honnet]

Hi Enrico, Hi Ovrebekk,

These exchanges are very promising!

I'm trying to get data (12 bytes) from 9 boards with nrf52832, hopefully at 25Hz at least (it seems realistic).

I'm dreaming about a cross platform way to do this without dongle but it seems tricky...

Would you happen to have any advice with example code?

Thanks a lot!

Cedric ;)

PS: I used to hope to do that with BLE broadcast (by hiding data in the manufacturer packets) but it's probably messy...

[ovrebekk]

Hi Cedric

Sorry for the slow response. I have been out in leave for the last couple of months, and didn't get back until yesterday. 

When you say cross platform are you thinking of mobile platforms only (Android, iOS), or PC's as well?

BLE is definitely the protocol to go for if you don't want to use a dongle, but if you need 9 boards transmitting data it becomes a bit tricky. 

When doing BLE broadcasting you can have 9 boards no problem, but the challenge with broadcasting is that you don't get any acknowledge, and you have to expect a high degree of packet loss when using broadcast packets. 

When establishing a BLE connection you will have acknowledged data, but there is no guarantee that the BLE host will be able to connect to 9 devices at the same time (the nRF52 devices support up to 20 concurrent connections when running the S132 or S140 SoftDevices, but phones or PC's might have a different limitation). 

If you had some relay device based on the nRF52 you could receive data from 9 devices there, and aggregate all the data on a single link with the phone/PC, but this isn't really any more elegant than using a dongle. 

If you can provide me a bit more details about your project I will try to come up with some pointers and advice. 

Best regards
Torbjørn