MRF24J40 - Microchip 2.4Ghz Wireless... anyone used it?

Wireless & IoT
21

It’s an 802.15.4 device - so it does the PHY and MAC layers. If you want to add Zigbee on top, you can, but you don’t have to. So broadly, you get Nordic functionality (better, actually, since you get all sorts of bonus stuff like energy detection, RSSI for every received packet and more) with the option of putting your own thing on top. That seems to be the going thing - use 802.15 as a base, add as little (or as much) functionality as you need.

The main thing I dislike about the zigbee standard, aside from the fact that it’s way more complicated than it needs to be, is the fact you have to join the “alliance” at $3500 a year to even sell a single product where you have built the software. Even Microchip’s Zigbee stack (which doesn’t need PHY or MAC since they’re already built into the MRF24j40) is 16k of code, which is a lot of code for an embedded device IMHO.

regards

Ian.

22

Not sure what you all are saying. I have the MRF24J40 working with 2k bytes. I can’t possibly see it ever being more than 4k. I’m not using Zibee or MiWi but wrote my own state machine (with help from Clark Leach, lots of help) and it does all I need it to do. All my code is in Proton PDS Basic. I plan on adding something like the MiWi P2p so I can have 128 nodes.

Using the Zigbee or MiWi stacks may well end up being 10k+ but you really don’t need that for a working system. And who cares? 16k out of 32 or 256k the new chips have is no big deal. Yes its a waste

doug

23

I took a loser look. Yes, it looks like the stack and some other functionality is pre-programmed in the OTP ROM from the factory. So updates to that code are not possible. The user code is stored in an external FLASH and loaded into RAM at chip boot.

OUCH!