Controlling existing relays

[twosh]

Finally found a combination that worked with the mega as a sensor. Here is the pin mapping if it will save time for anyone:

9 CE
10 CSN/CS
52 SCK
51 MOSI
50 MISO
2 IRQ

Doesn't require any config changes, but I am currently getting some "0;0;3;0;9;version mismatch" in serial monitor. Have 10 uF cap on the radio.

[twosh]

Tried powering the Mega from computers USB 5V, and two different 12V DC adapters - still getting version mismatch. Anybody knows what's going on?

[Sparkman]

@twosh From what I've read before, the version mismatch error is often caused by power issues. Are you getting the errors with the relays connected or without? If the relays are connected, try disconnecting them. If the error goes away, it's likely a power issues. Maybe try powering the radio from a separate 3.3v source.

Cheers
Al

[twosh]

Thanks for the suggestion, @Sparkman !
I have just the radio connected for now, but still getting that "version mismatch"-error. I will try getting a separate 3.3v power to the radio tomorrow and see if that would help.

[twosh]

@Sparkman
I tried powering the Megas radio from a Nanos 3.3V pin and GND. The Nano is working fine as a sensor by itself, so I guess the radio gets enough power from it. However, this way I only got "check wires" from the Mega... :(

Just a thought; if it helps, I'm defining these pins for the Mega in my sketch, but I don't see how that could affect this particular problem...

const int relayPin[] = {22, 23, 24, 25, 26, 27, 28, 29};
const int currentPin[] = {A0, A1, A2, A3, A4, A5, A6, A7, A8, A9};

[Sparkman]

@twosh What happens if you remove those lines or comment them out? I have used a Mega with an NRF24 successfully before with the NRF powered from the 3.3v source on the Mega, but I didn't have any sensors connected. I would try a very simple sketch first to see if that works.

Cheers
Al

[twosh]

Thanks @sparkman for once again nudging me in the right direction!
I went trough the code in my sketch a couple of times commenting out various sections and suddenly the sensor started functioning correctly. So I checked that function closely and noticed that I was out of bounds in a for-loop. that stupid NUMBER_OF_CURRENT_PINS +1 . That +1 had accidentally stayed there from an early version of the sketch. Correcting that, my sketch seems to load without problems - go figure! :P

[jemish]

how can I control fan speed using light dimmer sketch in openhab?

[phil pritchard]

@twosh said:

Great, thanks for the clarifications @Sparkman !

Being able to measure power would of course be a nice bonus! I'll think about it. I have another question (of course... :) ).

The Nano and Pro mini have only 6 analogue inputs, I would be having need for 8... Would I need to use two arduinos or is there any other way?

Best,
Tim

Have you thought of sticking a hall effect sensor to the outside of the relay. Or in the magnetic flux.

Phil

[twosh]

@phil-pritchard No, not really. As I've mentioned tinkering with hardware is new to me so I don't actually have any knowledge of what exists and whats possible from that side of the table. Would you like to expand on your thoughts? :)

I've ordered a bunch of these hall effect sensors: http://www.ebay.com/itm/221649135732?rmvSB=true

[Sparkman]

@jemish said:

how can I control fan speed using light dimmer sketch in openhab?

You may want to start a new thread as your question is a bit off-topic to the discussion.

Cheers
Al

[Sparkman]

@phil-pritchard said:

Have you thought of sticking a hall effect sensor to the outside of the relay. Or in the magnetic flux.

Phil

The relays are latching relays, so there would only be magnetic flux present for short durations. You would have a pulse when the light was turned on and one when the light was turned of, so you would have to find a way to count these pulses to know what state the light was in. The risk is that you would miss one and then be out of sync.

Cheers
Al

[gizzmo]

@twosh any update on your project?
I have exact the same setup, would love to see your code :-)