433 MHz Sensitivity (not range)

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Hello,

I’m just getting into Pimatic after having used several home automation projects (Nodo, Pilight). I really like it.

This is not so much a question regarding to Pimatic as it is to 433 MHz receiving.
I have sucessfully used several receivers with both Pimatic and Pilight with regards to range (20+ meters). It seems however that I have a problems with sensitivity. For example my doorbell (acdb-6500bc): if I just slightly press it the receiver already starts ringing, however for the Pimatic to pick this up I have to press longer (1 second, sometimes 2 seconds). The same applies to lightswitching with several kaku remotes. The lights switches with the slightest push on the button, but I have to really press it for Pimatic (and also before that Pilight) to pick it up.

Now for my question. Does anyone have any experience with this? Any advice? Most questions about 433MHz receiving seems to be about range, which is not any problem for me.

I have the feeling it has to do with noise, in that it takes a while for pimatic to filter out the signals.
I currently use homeduino with nano and an atmel receiver. Before this I used a cheap receiver with the pilight prefilter. In my experience they behave about the same way range (20+ meters) and sensitivity (problems with slight button touches) wise.

Any thoughts or suggestions for improvement?

Thank you very much.

Jurn

@JurnD said:

Any thoughts or suggestions for improvement?

If the sender / receiver power is supplied by Arduino you may experience noise generated by the Arduino’s circuits or even by the 5V power supply which may interfere with sender/receiver signal processing. A simple measure I found to reduce noise is to mount a 220uF cap (electrolyte) and one 100nF cap (ceramic) between VCC and GND power lines. It helped in my case. I think it is worth a try. See also http://electronics.stackexchange.com/questions/140761/arduino-how-do-i-reduce-the-noise-in-my-circuit

Hi JurnD!

I have noticed the same behavior when switching from pilight plugin to pimatic-homeduino. I think I have read that it has to do with the homeduino filtering with just one receive.
It’s not about the sensitivity of the receiver, I think. Maybe @sweetpi could comment on this at some point.

https://github.com/pimatic/pimatic-homeduino/commit/03ba394934f27d5ca9f785984d5d122ddf26b7db Contains information of homeduino latest commits. There seems to be a mention of repeats, but I’m not sure if it helps on receiving end.

@kitsunen From my experience, I can tell sensity of the receiver matters a lot, but of course, there are also other aspects to consider. The “rfrepeats” you referred to is for the sender-side only, as far as I know. It defines how often a data sequence will be sent repeatedly (7 by default). On the receiver-side the reception of raw data is handled by the Arduino code and there may issues with the tolerance settings of the receiver code to detect start and end of a receiption. See also https://github.com/pimatic/pimatic/issues/222

@mwittig , @kitsunen

Thank you both for your replies.
Tonight I will first try the capacitors suggested. Will let you know how it went.

Thanks.

Jurn

@mwittig Can you please show me a sketch of your wiring? Where to put the 220uF and where to put 100nF? Thanks.

@kenci I am referring to the Fritzing sketch @leader21 created (see 4. Homeduino - 433 MHz sending, receiving and even more!). Simply attach the caps between 5V and GND of the Arduino. See also answer post on http://electronics.stackexchange.com/questions/68817/sensor-decoupling-and-noise-reduction

I had the same problem with a ACDB-7000BC
The problem was that the resettime was to short.
I do not know how the resettime works but when i put it al about 6 seconds the problem was gone.

Same here http://forum.pimatic.org/topic/788/eurodomest-not-always-switching-off

@hansjeu The ‘resettime’ property is supported with the HomeduinoRFContactSensor and HomeduinoRFPir devices:

• HomeduinoRFContactSensor: “Time after that the contact state is reseted.”
• HomeduinoRFPir: “Reset the state after resetTime. Usefull for pir sensors, that emit present and absent events”

So i understand this has nothing to do with the hardware?
I spoke to soon. I discoverd today that the pii missed some doorbells.
My sensor is 2 meters from the signal.
Is there a way ro reset the Arduino compatible Nano via pimatic?

I am having the same issues after switching from pilight to homeduino (both with the low-pass filter). It seems like the homeduino plugin filters out some signals?

I had some luck with adding the capacitors to the circuit. At one point it even seemed a dramatic improvement. Slight button presses were pretty much instantly picked up. I was very happy cause it had not been functioning this well before. Then suddenly after about 20 minutes of fooling around with multiple devices the delay was back. I have no idea what changed. I must have some noise source somewhere, or my breadboard and cables are not high quality enough testmaterial.

After this I decided to build up the whole circuit again with new cables and a different breadboard. Also I got a long usb cable to test it in a different location. Well i must have messed up something because now my receiver is dead.

I then immediately ordered this set. Once I get it I plan to do some extensive testing with different locations, situations and hardware.

Thanks to everybody for input.

To be continued…

Jurn

@FrostedKiwi said:

I am having the same issues after switching from pilight to homeduino (both with the low-pass filter). It seems like the homeduino plugin filters out some signals?

Are you sure you didn’t have any problems with this while you were still on pilight? I can’t test it now, cause I killed my receiver, but I’m pretty sure I had the same problems there…

Jurn

@JurnD said:

@FrostedKiwi said:

I am having the same issues after switching from pilight to homeduino (both with the low-pass filter). It seems like the homeduino plugin filters out some signals?

Are you sure you didn’t have any problems with this while you were still on pilight? I can’t test it now, cause I killed my receiver, but I’m pretty sure I had the same problems there…

Jurn

Yes, 100% sure. I’ve never had any issue with pilight (I was still running version 5 though).
EDIT: http://forum.pimatic.org/topic/567/homeduino-arduino-nano-433-receiver-not-picking-up-short-buttonpresses
This seems to be the same issue…

you don’t need the attiny filter from pilight anymore when using homeduino.
homeduino has an own build in prefilter.
@sweebee has written something about pilight and attiny filter in use with homeduino at the end of this thread http://forum.pimatic.org/topic/7/arduino-vs-attiny.

so if you are still using the attiny prefilter from pilight, try without.
alsol you can search the forum for pilight filter

Clarification. The Noise Filter with the two capacitors I described in my earlier posts has nothing to do with the low-pass filter of Pilight (LPF). The LPF is realized by adding 5 resistors to the connections between the ATtiny and the GPIO connectors of the RPi.

@leader21 Thanks for this, I tried connecting the reciever directly by connecting it through my breadboard, but that didn’t work for some reason.
Just connected it directly, and it works perfectly! I’ll probably buy an arduino and connect the receiver through that, because the filter is indeed causing problems.

tjx @mwittig for the clarification! i remember posts from the pilight forum. users reported that the reception at pilight without filter/attiny was even better with their receiver
.
well go for the homeduino on arduino solution and be satisfied forever 😀

i undersrand that there is no solution?