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Topics - alobo

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Think Tank / Another wireless networking option: ESP8266
« on: June 15, 2015, 09:56:21 PM »
I stumbled upon this chip a couple of days ago, the ESP8266 Serial-to-WiFi thingamabob.

Seems interesting, and considering the wait time on the Flutter Wireless that I'd posted about earlier (they've started shipping! a good sign for a kickstarted project), this is plenty cheaper and has a pretty established community of users, it appears.

It's 3.3V only, with a built in RTC and can attach to existing WiFi or act as its own hotspot from what I've read so far. At $5 a pop (or less), that ain't bad.

Heliostat Projects / Reflection drift in late afternoon/evening
« on: June 05, 2015, 04:58:41 AM »
Hey Gabriel,

I've put together a heliostat using 12V 28BYJ-48 steppers. It's not entirely accurate as things go, but acceptable - a full degree of looseness in the azimuth, for example. But this is a small project.

Anyway, it seems to track the sun fairly well; in heliostat mode, I have it configured to reflect at a target directly due south, on the horizon (zero degrees in both axes). It seems to track fine in the mornings, but some time after noon and progressing into the evening the reflection drifts slowly upwards as the sun goes down. The gear ratios should be identical for both axes, and there doesn't seem to be a similar issue in the azimuth - it's loose, but the reflection stays more or less in the same location.

Any ideas? It could be some friction in the design of the altitude motor, preventing it from moving accurately, I guess, but if there are any other causes it would be good to rule them out as well.


Think Tank / Telescope star tracking?
« on: May 28, 2015, 02:53:52 AM »
I have a friend who's into a bit of amateur astronomy. I was thinking I'd point him to this program since it is essentially a big ol' star tracker already.
Could it be made to take input from something like Stellarium in order to track the night sky with a telescope? Or would it be better to modify the "SunCalculation" code to track another stellar object? When you reply here I'll point him to this thread so he gets the idea of what would be needed.

Think Tank / Digilent ChipKIT Uno32? Faster, more memory than Uno
« on: February 13, 2015, 01:58:31 AM »
So I had come across this microcontroller through a friend ... and from what I read, I imagine it could be a cheaper replacement for the Arduino Mega's accuracy, in the form factor / cost of an Uno.
Apparently it is mostly software compatible with Arduino, so the possibility exists that your code will work with minimal changes. AND according to the datasheet for that PIC chip (PIC32MX320F128) there is a built in RTCC, for which all you have to do is solder on a crystal (32.768 kHz, apparently).

Thoughts, think tank?

EDIT: it's 3.3V though. That may be a problem, although I think the A4988 stepper drivers are 3.3V compatible? Correct me if I'm wrong.
Relevant specs:
32-bit MIPS processor, 80MHz clock
128k Flash memory, 16k SRAM
42 I/O pins

Think Tank / Flutter Wireless
« on: October 31, 2014, 11:24:13 PM »
I came across Flutter Wireless while browsing the various tech blogs I keep up with, it's a funded KickStarter project.

It seems really cool. TL;DR: It's an Arduino-compatible 3.3V prototyping board with a TI chip enabling wireless communication, an integrated antenna boasting 1km range, 256-bit encryption, and easy support for mesh networking. AND ... it supposedly costs just $20. Reading their KickStarter page, it seems they're a bit slow on the production end, but no reason (yet) to think they might not deliver.

It could be cool to have your heliostat further away and still accessible without having to run wires. Perhaps a 433MHz transmitter/receiver pair off eBay would probably be cheaper, but then you'd have to set up your own networking infrastructure (or perhaps use something like the RadioHead Arduino library). xBees are almost prohibitively expensive in comparison - and often troublesome, to boot.
What do you CerebralMeltdowners think?

Hi Gabriel,
I'm researching larger arrays, so my question is: using your program, is 16 machines the actual maximum? Or is there space for more in the EEPROM?
Yes, I know it would become infeasible since they update one at a time .. this is just for my personal curiosity, really. Presumably if the Uno has 1kB of EEPROM and can handle 16, the Mega (with 4kB) can control 4 times as many?

Think Tank / GoSol (formerly SolarFire)
« on: August 08, 2014, 04:25:03 AM »
Hi Gabriel (and other CerebralMeltdowners),

I was reading up on other solar energy projects and came across GoSol. It used to be called Solar Fire. I'm willing to bet you've probably stumbled across it, since you've been at this longer than I have.
Anyway ... considering the success of your design, I would imagine this to be a really REALLY cool place for it. Apparently those guys have ready-to-build reflector designs for varying power levels - if the mirrors are all mechanically linked to maintain their relative angles, you could just plop in an Arduino, a motor to rotate the base and another motor to tilt the mirror elevation angle ... well, you can probably guess the rest (hint: AWESOME!)

Whaddya think? Imagine the potential for lower-income areas!  ;D

Heliostat Projects / Using one set of LDRs to calibrate sun position
« on: July 31, 2014, 02:19:00 AM »
Hi, Cerebral Meltdown!
You probably have gotten this idea before, but I couldn't find it on the forums ... so let me know what you think.
The heliostat work is incredible, by the way! This is just my 2 cents. (Or 2 rupees, as I am in India).

In a setup with multiple mirrors, you could set up code for an LDR voltage divider on one of the mirrors, and use it to calibrate the Sun position - compared to the calculated position - every now and again? That would almost completely take away any need for adjustment. I say "you", meaning experienced CerebralMeltdowners, because I'm not a particularly useful coder hahah  ;D

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