Thank you for the very fine design. Would you please mind helping with the sketch changes to read temperature in fahrenheit? Thank you.

Arnewiig, I’ve updated the repo, would you mind trying with the fixed version and let me know please ? Thanks Charles

Zydog, Thank you for you comment. Building removing all power consuming elements is one of the keys. For low power you cal remove all regulators and DC power converters if any. Powering with 2 AA/AAA provide 3V which can be fine, but take space ;-) The DHT11 is not the best sensor since it's slow and consuming power during conversion but with 2 AA/AAA it should works quite long as soon as you disable the sensor during low power sleeping mode. For ULPNode I'm working also on Gateway, currently an Arduino like but still testing with Spark Core / now particle and even ESP8266, they have more flash/ram add allow the gateway to do some other things such as displaying on a LCD/OLED

Hello, I have finaly build (recreated) what Charles showed... I have one problem now. How to turn MCP for the first time battery is inserted. Can someone show me how he did it? My schema looks like this and is EN by low state from voltage supervisor.

@cdmsjtr Sorry for my late response, I'm still working on it, the card is not in production yet, I need to finalize small things. Charles

HELLO CHARLES, CAN I REPLACE THE RFM MODULE WITH ZIGBEE ?

Dear Charles, I wonder how this story ended. It sounds impressive and just like the kind of board I am looking for. Can you give an update?

@Charles No problem ! And thank you for this board.

my family was looking for Acord 25 earlier this week and located an excellent service that has a searchable database . If others want Acord 25 also , here's http://goo.gl/ZkI6Nf