Hardware

@a-lurker said: So using your figure of 2.6 dB, which looks like an appropriate figure but could be higher; then this suggests, It's really a waste of time using the LNA+PA PCBs unless they are used at both ends. I largely agree, some refinements: If the sensor is mainly sending data and the gateway only acking, it is probably wise to have the PA radio at the sensor as I expect the data messages to be longer than the Acks 2.6 dB is not nothing, the range is extended by 34% (new_range = old_range * 1.34) assuming free space If the receiving side sees interference (ACI), a 20 dB louder received signal is for sure a better thing Any improvement people may witness ... is probably just because the LNA+PA PCB uses a far better antenna Yes, good antenna's can for sure help but be sure you know what you are doing. If you use a dipole antenna and point it to the other node it will not help you and likely even kill your connection. The antenna efficiency of the on-board antenna's can be pretty good, assuming things are matched correctly. If the external antenna is also matched correctly, it will have about the same efficiency. The same efficiency means that same total power is transmitted. The remaining difference then is that but the on-board antenna will have less directivity so the energy is spread out more evenly where for instance a dipole will focus most energy perpendicular to the dipole. A pretty good trick, that is how we can still receive signals for the Voyager 1 that is almost out of the solar system using a 20m dish antenna. But ... do point this antenna 1 degree wrong and you will not see the signal.

@Zeph said: Or better still, optocouplers or an analog switch as described above... Yes, that's a better option as relays are quite power hungry and bulky.

@naveen said: What is APM? Arduino Pro Micro. Sorry, sometimes I spell it out, but we use the term a lot here. Isn't the maximum one thing connected to either power or ground since there is only one pin for each? No, there's not one to one association of that sort. For i/o pins you have to take some care not to try to drive too much output load, or let different inputs fight with each other, but for power and ground that's not the issue. Well, you do have to keep the draw on the regulated power reasonable - often they are spec'd at about 150 ma (including the on board load for microcontroller, LED, powered outputs, etc), but that can vary. I was thinking about doing something like you do, but was hoping there would be something more elegant. Are you not worried that the bare wires will touch other pins, etc.? Yes, I only do that when I have a mounting situation where it's OK. And I might coat it with Liquid Electrical Tape in a few cases. AND - I too wouldn't mind learning a more elegant solution.

or i might use one as a multi sensor - temp, light and movement..

@Yveaux You might be right, but then again how would I learn about shift registers if I don't use them? :-)

You may want to disconnect everything and just leave the power supply and arduino, then measure the RAW pin and VCC pin, RAW should be anything above 5V, VCC should read 5V for the 5V version and 3.3V for the 3.3V version. Any other readings on VCC suggest that your regulator on the arduino is faulty.

Do not mix digital and analogue outputs of the light sensor Lm393 is used to switch from low to high above the light threshold. Etc. it provides digital (binary) output. If you connect it to arduino analogue ping you mostly will read binary data with some noise. Analogue output of this sensor is bypassing lm393 and provides you a range of analogue levels depending on the light level For me a cheap 5mm round photoresistor is very sufficient as a light sensor. Just create a divider with photoresistor on bottom and fixed resistor on top. Fixed resistor should be with resistance much lower than dark resistance of the photoresistor, so you will read 1023 in a dark room

Hi. Just wanted to let you know that I've tested this with an Arduino Leonardo, with the RF24 library bundled with "My Sensors" (from GIT), MISO MOSI and SCK connected to ICSP as stated on the offcial Wiki: http://arduino.cc/en/Reference/SPI also works for the MEGA 2560, but you have to connect to the ICSP or use the 50-52 pins (if using it for the Ethernet gateway for example) Regards.

Thanks That might have been my issue. I did notice the 5v step-up LED seemed to brighten at times, which I never noticed before. This sensor is a Micro Pro 3.3v with step-up to 5v for the sensor. It is powered with a 5v 1a wall plug. Anyhow I recompiled the sketch removing the EPROM write after trying some pull down resistor values, no luck, put it back in its original location and so far it has been working fine. Will have to watch it for a while.

It's not recommended. Let the gateway handle radio<->serial communication to minimize missed messages.

Yes, but you need to reconfigure io-pins correctly. Join the discussion here: http://forum.mysensors.org/topic/115/implementing-multiple-sensors#780

Basic sensors that you are using for logging and alarm are ok. However, when starting with power/switch/dimm, then security starting to be a big issue. (Also when using the sensors to control something) I hope this boards will be sold with a big warning on that point. (I'm not negative to mysensors and using those myself, why would I else be here :). I'm just not a fan of people seeing this as a complete HA solution)

@tjay4x4 I completely understand. Until about 3-4 weeks ago I did not even know what an Arduino was. Yet, here I am creating a plugin for Indigo (I did not know about Indigo until about 8 weeks ago) and creating/testing very basic sensors. Today I started creating my first 'home-grown' sensor and guess what: You have to try it to understand it :) I know from experience that you can ask just about anything when you get stuck...

@hek: Is it technical "cannot" or legal "cannot"? From technical angle it's not walk in the park but it's been done (google z-force and open-zwave).

Fantastic.. Thanks for this.

@NotYetRated Biggest difference I see is the USB FTDI onboard, good if your are connecting to a vera or something needing the comms. If it is going to be purely a sensor node, I don't see why u need this. The pro mini has 5v and 3.3v variations, or look for switchable ones, pro mini enhancements. If you are frequently reprogramming it, then easier with the nano, I'm fine using a separate ftdi board for programming purposes.

Hi Andriej, I won't do that because I have experienced quite some issues with that frequency. Some of my neighbours use the same frequency and I have had my (kitchen) light go on and off without doing anything (or even being home) too many times with these 2 devices. That is why I decided to re-use their housing but not the technology... But, thank you for the suggestion! Cheers, Marcel