Interactive web site of Télécom ParisTech's ELECINF344/ELECINF381 Robotics and Embedded Systems classes (a.k.a. ROSE, 2012 session).


MAESTROSE – No more nRF24L01P

We have had a bitter surprise today: we just realized that with our nRFL2401+, the only information about received power reduction we can get is whether we are over or under -64dBm, while we planned on using a precise value of attenuation to get the distance between two modules. It means  that we will eventually have to rely on our good old XBee Pro. Now that we know (almost) all the components we will need, we are currently designing our PCB. We must focus too on a way get more precise results with our XBee (our resolution right now is still far too bad).

We are a bit disappointed to have to give up on our nRF24L01+ (we had quite a good time welding it to our cards, and we have spent a few days trying to use it) but at least now we have an actual basis to work on.

Guillaume Chelfi

Possibly related posts:

  1. MAESTROSE – Distance evaluation

4 comments to MAESTROSE – No more nRF24L01P

  • What do you mean by “we just realized”? Did you realize that when experimenting?

  • chelfi

    That’s my fault here, when I read the datasheet, there was a line that seemed to mean that the RPD register’s content would be the received power (section 6.4 from the datasheet). I thought that it would be perfect for what we needed. We then focused on using the module and when I came back to this specific section, I realized it was in fact a 1-bit register (8 bits actually, but with 7 reserved and stuck at 0) that triggers when the received power exceeds a threshold (-64dBm).
    According to what I have read, there is no other way with this module to get this value, so we have to drop it and try again with the XBee.

  • François-Xavier

    Hi all.
    I have several questions concerning the MAESTROSE project:

    - Why did you drop the DHEXTROSE project ? Was it for financial, technical or personal reasons ?
    - What precision do you expect in the distance estimation by measuring the received power of the ZigBee module ? Have you taken into account all the multipath/fading/interference issues that may arise with this method ? What will be the typical range between the modules ?

    Plus one more general questions concerning all the projects, is there a dedicated site for every project ?


  • FX: I can answer the last question. There will be a dedicated site for every project, starting ca. mid April.