SparkFun Forums

[SamBamboo]

Hey guys! I am designing a project that will incorporate a bluetooth module and a nordic module. Basically a smart phone will connect to the device via bluetooth, send it FFT analyses of an audio stream :violin: , then the device will relay that information via Nordic to multiple devices.

I plan on using duck antennas for the bluetooth and nordic, they will be spaced apart about 3.5 inches.

So are there things I need to watch out for when designing the pcb which will host a bluetooth module, nRF24L01 module and of course the microcontroller? Any interferences ect...

Thank you!

[marcovansteen]

Since WIFI and Bluetooth go together in each smartphone these days, and WIFI power is much stronger than Nordic, I'ld guess that there should be no big problems.

The two 2.4G receivers may suffer a bit of 'blind time' when a transmission from one of them saturates the other's preamp. This will cause some extra packet losses that your application must cope with in terms of 'hickups' / response time / latency.

But. If I may propose a different approach. Why not avoid the nordic transceivers, avoid the whole two-antenna board, and connect the smartphone directly with the devices using Bluetooth Low Energy, by equipping your multiple devices' with BT LE transceiver modules instead of Nordic modules?

I mean modules such as:
http://www.mouser.com/Bluegiga-Technolo ... 1aZ1yzrd03 (should sparkfun carry such?)

And there is also an example of tracking BT LE using cheap NRF24L01+ modules:
https://dmitry.gr/index.php?r=05.Projec ... E%20fakery . I have no idea how mature that code is, by the way.

Disclaimer: I must admit having no experience with BT LE at all, so I may be missing something essential

PS: I don't see BT 4.0 or BT Smart or BT LE modules in the sparkfun list... wonder why is that?

[SamBamboo]

I do like the BTLE modules! I believe Bluetooth 4.0 is BTLE...? I think?

I chose to use Nordic for:
1. There will be many (20+) devices listening to the Nordic messages, and they will ONLY listen, never talk back.
2. The microcontroller will also be able to take in audio and do realtime analyses, essentially doing the same thing a smartphone would do but from an audio line in.