OOK receiver based on modified Jeenode voor OOK, ELRO devices (pulling my hair out :-)

Added by jm_wsb about 6 years ago


I’ve followed the guide:\_OOKASK\_with\_a\_modified\_RFM12B to modify a standard 868MHz jeenode to receive OOK messages.

I’ve did:
- 100 ohm resister between P1 Analog and FSK/DATA from RF12MB receiver
- load the sketch RFM12B_OOK, also tried OOK_reley2 and demo_kaku (also RF12demo)

But I never succeed in receiving any message from a KAKU type A transmitter (remote control) or an ELRO one.

The only thing I did not change was the capacitor.
I tried it from different ranges, but without success.

Anyone an idea what I am missing.

Thanks in advance,

Replies (77)

RE: OOK receiver based on modified Jeenode voor OOK, ELRO devices (pulling my hair out :-) - Added by jseixal about 6 years ago

After running some more test with different values for Data Rate and for GAIN and DRSSI, I think I got the best results when using the following values:

 Data Rate = 0xC647 (4.8kbps);
 GAIN and DRSSI = 0x948B (Gain = -6 dB and DRSSI = -85 dBm).

Still, the distance at which the Jeelink is receiving data from the temp/hum sensor is very short. Since I was also not receiving valid KAKU data from the remote control I mentioned in previous posts, I decided to take the code of the KakuADecoder class from the ookRelay2.ino sketch and give it a try. It worked like a charm. Immediately, 5 new entries of KAKUA decoded messages were displayed in the Serial Monitor window. I tried it at 15-20m with walls in between and was still receiving data when I pushed the remote control buttons. Later on, I tried the Jeelink close to a OS weather station console, and at 8-10m it received OSV3 messages from the remote sensors.
By now, I’m very much convinced that the Jeelink setup and the modifications are correct, and I’m very pleased about that too. The temp/hum sensor I’m using, though, does not seem to be up to the task, I think it’ll need to be replaced…

Since my problem seems to be solved, I’m attaching the source code I’m using, which is basically the original Ook_OSV2_433.ino sketch with some minor changes to the rf12_init_OOK() function, the KakuADecoder class and a function to test the LED. I’m also attaching a picture of the Jeelink with the modifications needed to receive OOK/ASK data. Perhaps someone will find them useful.

joop: Thank you very much for your help.


RE: OOK receiver based on modified Jeenode voor OOK, ELRO devices (pulling my hair out :-) - Added by joop about 6 years ago

Jorge,thanks for your investigation ,I will update the wiki with your findings.

Because you are using the flat SMD crystal you could maybe try
to set the frequency lower with the Frequency Setting control word.
See this post from martyn\#message-814.

the flat SMD is a tighter tolerance (better than +/- 10ppm) but runs a tad high.

I looked up the shortest time interval from some protocols.It seems
that the Oregon Scientific is rather fast , maybe because I use a 150 pf capacitor.
my results are better for fast on/off changes.(OOK Oregon Scientific)

shortest time interval

KAKU                           370 uS 

FS20                           400 uS 

Oregon Scientific  ver 2.1 3.0 200 uS 

When I get hold of a 433Mhz RFM12B I will try it with different capacitor values.