Hardware

Hello, I only managed to make it work ties in: #define SOFTSPI #ifdef SOFTSPI const uint8_t SOFT_SPI_MISO_PIN = 12; //A0      const uint8_t SOFT_SPI_MOSI_PIN = 11; // A1      const uint8_t SOFT_SPI_SCK_PIN = 13; // A0 #endif I do not know how to explain.

Just calculate how much current flow you need and take relays that can handle it. P=UxI so 9W=240VxI and from there 9W/240V=0.0375A per lamp. With 10A relay you can drive 266 led lamaps ;)

@GertSanders No conclusive reading from the datasheet. I will do some measurements later. .. [image: 1456219794829-upload-af85eb98-f577-4011-96e9-ef35b5ef97bb]

@AWI it was not clear, but I was thinking of using a mosfet in combination with the water level sensor shown in my first post, which is in fact drawing about 1.4mA when dry, and around 15mA when put in water. Add those 1.4mA to the those taken by the step up, and it feels like the mosfet would lower that a lot when the node is sleeping (if I read the datasheet correctly, it draws between 25 and 250µA, depending on its operating temperature).

I bought a couple of the cheap one. If it sucks I can use it as light sensor ;)

Anyone? As mentioned, I prefer to use the RFM69HW, one reason is to be able to put a unit in the mailbox to notify when there's mail to picked up, and that is a little way off from the house...

Thanks as well. I decided to go with this alarm, http://www.ebay.com/itm/like/252094388277?dest=http%3A%2F%2Fwww.ebay.com%2Fitm%2F252094388277, probably more than I needed to pay, but I liked the idea of a strobe alarm.

@stedew Thanks for the info. My problem was much simpler, as I hadn't defined the right interrupt pin in the software that the rfm69 was connected to. So after setting this, I had communication up and running.

for me it has impact on the accuracy of readings... if we can speak of accuracy on MQ series sensors...

FYI, @Bandra hasn't been "online" for over a year.

found the issue, the polarity was wrong...

Thank you for your post. I also found this http://www.seeedstudio.com/forum/viewtopic.php?f=10&t=989&sid=bbe4d6f1ab9f050788e5fa5b41b46069 Can you check my picklist: Uno r3 W5100 Ethernet shield Breadboard Resistors Some cables Flowmeters Can I split the 5v from the uno r3 to the flowmeters?

With an external regulator it has been running already for 24h :) thank you.

Does the Uno have a 3.3V-reg while Nano get 3.3V from it's Ftdi-chip (don't remember) Could Uno/Nano board selection in Arduino IDE effect the Ftdi behavior?

@AWI Thanks. I'll search for that

You might find fix here. https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=110164