Radiometrix RX2 Gotcha

1 post / 0 new
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I've been playing with their Tx2/Rx2 /433 with good success.... I thought I'd be smart and use their 'carrier detect' example from one of their data sheets.... It would cut down the Rx 'ON' time, whilst it looks for a valid signal(no carrier most of the time). I usually look for a couple of syncs (0x55) then stay awake if I find them, or go back to sleep for 150mS if I don't.
Anyway, on closer examination, they show a PNP transistor connected to RSSI ( which goes from 300mV to 1.1V on max signal strength. It should to be an NPN.
I've hooked it up to a port pin and on 'Rx module wakeup' (after 1.5mS) I test the pin for low (carrier detected) and go back to sleep if it's high.
That reduces the minimum required on time from 6mS to 1.5mS
The Rx module is 'powered on' directly from a port pin and works on the bench..... I might have to switch the ground on with an N channel FET if I get signal quality issues, but so far so good.
Probably one of the easiest RF pairs I have been able to get going.Yes, I'm binning the cheap-skate Int RC solution and using Xtals both ends and data Tx/Rx at 9600 baud.Has the benefit of perfect debugging via a PC terminal @9600.

Last Edited: Fri. Oct 16, 2015 - 02:19 PM