Hello All,
Does anybody know if it’s possible to configure the nrf24l01 as some sort of ‘open’ receiver that will pick up any sort of junk on 2.4Ghz?
I’m trying to test a receiver setup but can’t get it to pick anything so I’m hoping that by disabling CRC somehow I’ll pick up something at least!
Thanks,
Leo
It is possible to do that. I’ve forgotten how, though.
Leon
AFAIK, you can do something similar to this with the nRF2401, but the 24L01 can’t (although if Leon can remember how to do this, I would be interested as well). In order to get a packet, it has to follow certain rules for the 24L01 to register it as a packet. The best way to start testing out your circuit is to make sure that at the TX module, you are getting the TX_DS interrupt. If not, then you can’t recieve something you didn’t send. 
About the best thing you can do on the 24L01 (that I know of) is to use the CD bit to tell if the RX is seeing any air traffic (keep in mind this is just a bit, not an RSSI measurement).
I might have been thinking of the 2401.
Leon
Thanks both for the replies,
I’ve tested the CD bit & it’s low all the time despite (I believe) another nRF24L01 transmitting.
Could this indicate a fried chip?
Leo
The possibility of the chip being fried is probably pretty low (but it is certainly not zero). You need to make sure that the TX unit is actually sending something, as I described in a previous message. This is easy to do by verifying that you’re getting the TX_DS interrupt.
It is the nRF2401a that you’re thinking of. Turn off shockburst and it will dump out anything that comes in - given similar modulation, etc.
iharris:
It is the nRF2401a that you’re thinking of. Turn off shockburst and it will dump out anything that comes in - given similar modulation, etc.
As far as I can see I can only disable the enhanced part of the shockburst by setting the relevant data pipe bit to zero in EN_AA (address 01). Is that correct?
Brennen, thanks for the suggestion, I’ve got a unit operating in TX with the TX_DS interrupt.
Not sure where to go from here…
Leo
You’re right - but to be clear, you’re discussing the nRF24 L 0 1 as opposed to the nRF24 0 1 A - the L01 being a more advanced version of the 01A (it has 2Mbps data rate, a different uC communicatoin mechanism, 5v tolerant pins and no non-shockburst method)
Well it’s not quite a professional testing method but I found that by disabling the auto ack (EN_AA) (I had CRC set to 1 byte also) & holding a mobile/ cell phone close to the antenna while calling out seemed to produce an interrupt!
They seem to put out alot of stuff on the RF so no wonder!
Leo