Create my own (Arduino) sensor for RFXtrx433

[Meinaart]

What's the best way to interface an Arduino with the RFXtrx433?

I want to create my own sensor that is compatible with the RFXtrx433. I prefer using an existing protocol so that it's compatible with my Vera Lite controller. But I am not sure which protocol is the most open/documented.

I was considering using a JeeNode but I saw that they use a different frequency (866Mhz). Since it's going to be a sensor I could just use a 433Mhz transmitter but I don't know which unit will work with the RFXtrx433.

SparkFun carries a 433Mhz transmitter (http://www.sparkfun.com/products/10534) but they say on their product page:

These modules are indiscriminate and will receive a fair amount of noise. Both the transmitter and receiver work at common frequencies and don't have IDs. Therefore, a method of filtering this noise and pairing transmitter and receiver will be necessary.

So it's probably not going to work with the RFXtrx433.

[Digit]

Have you seen (and read) this: http://talk.jeelabs.net/topic/199
The topic is more than 2 years old, so I don't know how accurate all the information still is.

[AshaiRey]

Have you considered project nodo?
http://members.chello.nl/p.tonkes8/index.html

en
http://www.samenkopen.net/action_product/976666/35240

[knasen17]

How well is the KAKU/NEXA protocol documented? Can that be found in the link above to the NODO project? (Sorry my Dutch is poor =-)
What do you want to measure Meinaart?

[Meinaart]

If I have time I will look into Nodo.

I want to measure light knasen17, see my other topic
http://www.domoticaforum.eu/viewtopic.php?f=7&t=7535

[krambriw]

Hi, I needed something similar. I wanted to measure the sunlight level to have some additional rules for controlling awnings.

I took a cheap temp/humidity device from UPM/ESIC and modified it with a light resistor instead of the thermo resistor. In the picture below you can see that I also took away the connector for external sensor and instead added an adjustable potentiometer for tuning possibilities.

Of course your readings will in this case be in temperature so you need to have some code handling this. Maybe the humidity sensor could be replaced instead giving you a percentage value.

I think also the potentiometer could be replaced if you accept to tune the thing using some kind of covering for the sensor like a piece of (white) plastic tape or tipp-ex.

Best regards, Walter

Image1.jpg (21.28 KiB) Viewed 7574 times

Image2.jpg (54.8 KiB) Viewed 7574 times