60 cells (30V) PV modules for 24V off grid?

[lifer]

I totally agree with you.. seems like I underestimated my needs when I've choose Arduino. I don't want a standalone application but a dynamicaly/interactive one. I want to be able to remote control/log all those data and to integrate the rest of the household activities - like lawn sprinklers, pet feeding, home lights and so on.

I know that RPi has a different target and that's why I thought about BeagleBoards/OLinuXino instead (as they both have Arduino-like GPIO ports). The advantage of using a microcomputer instead of a microcontroller is that you could actually run a separate script for each and every activity and change it at any time without disturbing the other.
And I have no concerns about the power sinked by the microcomputer (few watts) since I have "free" energy now!  

PS: Anyway, I'm not upset on Arduino!.. I might use it for a small/standalone project one day. It's nice to see that good ol'days of  flat assembler are gone!

[lifer]

I just want to say that I've decided to go with.. Arduino DUE!

- 32bit ARM architecture (84Mhz clock speed / 512 KB Flash / 96kB SRAM)
- Digital I/O Pins: 54 (of which 12 provide 8bit PWM output)
- Analog Input Pins: 12 (12bit ADC)
- Analog Outputs Pins: 2 (12bit DAC)

That's plenty of high resolution analog inputs/outputs and GPIOs and (the most important thing) I've managed to connect it to my "home control" computer so I can remote read/write all those ports. The next step will be to buy a RIoTboard/BeagleBone microcomputer to swap that old "home control" PC.

Regarding my PV panels - they're doing just fine (direct charging the batteries). And it's going to run this way for a while because I just don't have time to build the MPPT charger right now. My big struggle is to build that 4kW sine inverter to complete the off-grid adventure.

PS: Thanks again, Damon.. your previous post made me decide to go with two separate boxes.

[DamonHD]

Happy to have been of help!

I'm about to have fun this afternoon getting a couple of my ATmega (UNO-like boards) send (extra) stats to one another for logging, piggy-backed on some other data.  Note that even in this simple case the radio board has something like another microcontroller inside it...  "Great fleas have little fleas upon their backs to bite 'em,: And little fleas have lesser fleas, and so ad infinitum."

I will be interested to know how your DUE experiments turn out.  Certainly one of the Cortex ARM processors is on the horizon as a successor to the ATMega I'm currently using...

Rgds

Damon

[frackers]

I've been playing with Arduino (MEGA) for two days and I'm pretty disappointed about its capabilities. I just need something that could be remotely and dynamically programmed (not being completely erased each time I'd make a small modification) so I guess I'll go with BeagleBoards or OLinuXino (or maybe pcDuino? - there are many available options).

If you want to stay with the Arduino Mega then take a look at https://github.com/g8ecj/turbine which does logging to an SD card as well as live online logging via the USB/serial port. It does all the control stuff for a PWM dump load and can switch an inverter via its' remote control - all with a Mega 256.

For irrigation, then more grunt is required, how about a wireless router - complete low power linux system in a neat box that comes complete with PSU or runs direct off 12volts https://github.com/g8ecj/irrigate - use one with a USB port and a USB to 1-wire adapter and you're off!!