Great fun to see all these build pictures!
My pic of the day is a trivial battery powered DHT22 sensor just to try things out with prototyping, programming and connecting to OpenHAB. This is my first project since highschool. (The gw and first sensor is on a breadboard.)
It feels great to be soldering again after almost 30 years and I'm really looking forward to step into the MySensors world!
I second the IKEA alternative for USB chargers. They are hard to beat as a huge company with focus both on cost and safety. And the lygte-info.dk is a great resource.
Just remember that a USB charger is optimized to deliver 1-2 A for a couple of hours at a time. That is very different to providing 50 mA continously. I'm thinking of heat dissipation but also efficiency at low power. (So use the lygte-info.dk link to find a good one that performs well at the power you need.)
Hi,
First of all: I really appreciate the simplicity and flexibility of this board!
Now then, I have a problem with battery life which is only around 3 weeks for my DHT22 node and around 8 weeks for my BMP280 node. Both are 3.3V mini clones with NRF24 radios (probably clones) that run on 2xAAA batteries and a booster. I use NodeManager for software and report sensor values in 2 minute intervals. LED and voltage regulator has been desoldered from the Pro Mini.
Why isn't battery life better - am I missing anything obvious?
Can/should I remove C2 (10uF) and C3 (0.1uF) capacitors? I added them first but after checking the schematics I now think they are not used at all for the battery/booster setup?
What battery life can I expect for a BMP280 on 2xAAA batteries and booster?
New batteries report at 3.13V. When the nodes fail, reported battery voltage is around 2.6V. However, when measured I get it to around 1.6V (at no load). This could be a software problem but I include it as a clue. My setup in NodeManager is:
battery.setBatteryPin(0);
battery.setMinVoltage(1.8);
battery.setMaxVoltage(3.1);
You are of course both right! It was only intended to get things going so I didn’t want to complicate things. My “production” sensors will be quite different. Maybe I’ll save this one in a frame on the wall 
@martim I'm running OpenHAB with a few MYS sensors (and other subsystems) and I really like the system system. It is complex with a steep learning curve but incredibly flexible and powerful.
As for your problems with MYS/MQTT I have no solution but to use the direct connection over ethernet instead. I have tried switching to MQTT twice and failed miserably both times.
The MYS addon requires the new MQTT binding which easily collides with the old one. (The new MQTT binding is almost ready for release so it may have been fixed, if you are lucky.)
I don't know if the cause of this problem is with the OpenHAB MQTT bindings or with the MYS binding but it was not trivial to fix with the instructions available. As I could not really see any upside of using MQTT except to have an "all MQTT System" I went back to the ethernet connection which works fine.
I would recommend connecting it as ethernet connection first and get it working that way. Then you can switch to MQTT if you want to. The biggets hurdles are installation of supportive packages (mqtt and serial transports) and getting MQTT to work in parallel with MQTT binding version 1. If you post your logs (WARN level for the Mys binding) I can try help you decode it.
Can you please add a link/button at the top of the page - Download and installation - that links to https://github.com/tobof/openhab2-addons/wiki
It is a very useful page but also very hard to find.
The two middle buttons should preferably be removed as the "Support Forum" button is sufficient.
@bjacobse I believe you can replace the meter yourself if you own it yourself and have the necessary skills. I live in such an area and was told I could mount it myself if I was confident enough. But of course, the fault will be yours if your bad job causes damages. In reality it is quite unlikely that you can mount it badly and not notice the problem immediately.
A more critical issue is that water meters are usually owned by the municipality or water company and they are sealed. It is impossible to replace the meter without breaking the seal and when the company notices they won't be happy at all.