Range - nrf24l01 - MiRF v2 - nRF24L01 - RP-SMA

Wireless & IoT
1

Hi all,

After being delighted with the SFE modules using the nRF2401a, I got a couple of the nrf24l01 modules, since I needed the circuit to run at 5v and this seemed the best way to do it.

I’ve got it all working, including all the PIC code that interfaces to the new modules, but I have to say, the range is pretty terrible. It’s nothing like the range of the nrf2401a modules, and that includes the ones with the ceramic antenna! I have two of the mIRF v2s, one with the 4 inch antenna and one with the 7 inch antenna - I would have thought with these massive babies attached I would have plenty of range.

I’ve checked the code and I’m outputing at 0dBm.

I wanted another module and checking the website, the cost of the ceramic antenna version is about 50% more expensive than the SMA external antenna version - about $10. Very strange given that the BOM is less than $1 different (even the retail SFE prices of a ceramic antenna vs the SMA connector are $1 different). The warning about using the SMA version for “range and cost” is a little strange too. With an external antenna factored in, the cost difference is only about $2.

So, after my experience with a chunky antenna, I’m now a little worried that one of these ceramic versions is going to have the range of, well, only a couple of metres and certainly less than the nrf2401a versions.

Is this a factor of the different chips? Or the module designs themselves? Why would the nrf24l01 modules have such a smaller range especially with large external antennas?

When I’m finished testing I’ll release all the source to these projects - my plan is to build mesh packet-based networks for little modules to talk to each other (time, temperature, switches, lights etc).

kind regards

Ian.

2

Because SFE used the same PCB for both versions of the MiRF V2, the ceramic antenna has a ground track underneath it which reduces the output considerably, giving a range of just a few metres.

Leon

3

Hi Leon,

Yes, I see that’s the case with the ceramic version, so that one’s a no-go. However my range issues are with the SMA external antenna versions, which don’t have anything like the range of the nrf2401a versions, despite the external antenna.

Perhaps someone has had experience with the [olimex versions of the same? They claim a range of 62m - 65m.

I noticed a link to the [Quasar module based on the TI / Chipcon CC 2500, that claims 50m range, but I’d rather not have to write another set of rf code. Unfortunately, they require 3.3v.

regards

Ian.](http://www.quasaruk.co.uk/acatalog/FM_Transceiver_Module.html)](http://www.sparkfun.com/commerce/product_info.php?products_id=8250)