Do you know at what speed RF12 sends data by default ?
I am interested in making an ADC and then send all data by RF for processing at another node
230V mains stepped down to ADC levels
then this sends data via RF to another node and then to PC via serial
any idea what sample rate i could get on this ?
Idealy would be to have Ethernet conectivity but this i assume will take the speed even lower (i don't have an ethernet plug 'yet' to find out) anyone tested this ?
RF speed
(13 posts) (5 voices)-
Posted 23/12/2010 13:20:46
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The default speed used by the RF12 library is approx 49.2Kb/s.
You can change the rate quite easily with the rf12control() command after the initialize.
The default set during initialize is 49.2Kb/s rf12control(0xC606); I've had no problem with rf12control(0xC602); which is 114Kb/s. It will reduce your range however as the faster data rate is susceptible to more interference.
You can pick values inbetween too. 0xC604 = 69Kb/s
I wrote a little program (windows, but should work in wine etc) to help calculate the various command settings. The one you are interested in is the "data rate command", half way down on the left hand side.
A hard wired ethernet should be well in excess of this. I can't remember what speed the ethernet card is connected to the ATmega at, but it's got to be well above the 100Kb/s.
Posted 23/12/2010 15:06:38 -
Hello,
I'm trying to lower baudrate with rf12control command but it seems that jeenode "stick" in the rf12control functin because the next line 'serial.print' never display message.
//initialisation du module radio RF12 rf12initialize(1, RF12868MHZ, 33); // Reconfig du baudrate : 2400 bauds rf12control(0xC68F); Serial.print("\nInit Radio OK");I've tried with other values but it doesn't work... any idea?
Posted 21/01/2011 21:35:29 -
Hi, I might have a problem with the RF12 module... I think it is no longer working :-( I've try to send a "standard" rfinitialize command and jeenode is stopped is this function... I'm going to check with my oscilloscope if signals are fine or not.
Posted 22/01/2011 09:12:40 -
hi, i've made investigations, with other jeenode/jeelink, baudrate change command line works fine (I've set it to 1200bauds, and the range is better, event trough walls!).
It seems that I have now a jeenode with an RF12 module which is out of order... don't know why, it was well working before i've tried to change baudrate :-(
any issue like that known?
Posted 23/01/2011 13:18:54 -
It might be worth just going round the connections on the RFM12B and the bottom of the ATmega and freshening the solder. Dry joints can do all kinds of weird things.
Posted 23/01/2011 14:31:12 -
That's it!!! Now it works!!!
Thank you... I was ready to replace the rf12....
Posted 24/01/2011 17:48:16 -
YES! me too :-)))))
I was quite sceptical with this advice but I have to admit that the RF12 is alive now :-) I was thinking that an ESD has damaged the RF part or anything like that but a quick re-heating of solder points of atmega and RF12 was ZE solution!
Thank you !
Posted 24/01/2011 18:10:46 -
Waitaminute... so there is no problem with the RF12 driver?
Hm, that's nice for a change: a bug which vanishes all by itself...
Posted 24/01/2011 23:08:20 -
Yay! \o/
That's great news!
BTW it's very tricky to kill something with ESD these days (no this isn't a challenge). The shunt diodes protect the devices from even the most enthusiastic nylon clad hobbiest :o)
Posted 25/01/2011 01:29:38 -
not really a bug but maybe a case which is not monitored : I think that I had a bad solder point on I2C interface , RF12 was not responding and RF12 function was waiting ... maybe a response timeout could fix this problem, returning "Time out response from jeenode" ;-)
right now : 3 jeenodes (with SHT11) + jeelink (plugged in a sheeva plug) are well working : click around : http://minbiocabanon.free.fr/staticdomini/temperature.php#
Posted 25/01/2011 13:02:55 -
Oh very neat... The last option, prefs throws up a 404, but that's a very nice clean site. What do you use to generate the graphs?
Posted 25/01/2011 13:56:53 -
thank you, yes prefs page is not existing yet ;-) Graphs are generated with Jpgraph php lib. This site is a "miror" of my sheeva's server web, because i can't access to my sheevaplug (no opened port on WiMAX) from the web. So, i process an upload each hour. advantage : no hack possible ;-) drawback : not as dynamic as in my local network (real time info).
next steps with jeenode : thermostat of my pellet stove , "puits canadien" bypass ...
Posted 25/01/2011 16:38:55