Must-haves for EASY DIY controller?

oh, for sure! I saw a DIY arduino gameboy type thing at hacktronics or liquidware or one of those sites that i got a kick out of. expensive kit, but definitely VERY cool.

After looking over alot of products and reading lots of beginner tutorials, i'm still pretty lost, though. This is probably a stupid question but, how many shields can you stack on top of a normal arduino (not mega)? and how many on mega? can a shield that fits on a normal board fit on a mega?

I see that there is an SD card shield. Would that be easier than having it log data on a computer? I wouldn't mind pulling the SD card out and throwing it in my computer once a month to analyze the data. I would still want to be able to check what current params are though.

I also saw that there is a bluetooth shield or module that was around $20 IIRC (nope, it was more i was confusing it with GPS). I have a usb bluetooth dongle that works pretty well for being $2. I wonder if I can write a windoze gadget that can display everthing the arduino is doing/monitoring and have it connected wirelessly via the dongle. Tank is close enough for a long usb wire, but wireless would be better. maybe xbee would be better or ethernet shield connected to a wireless adapter, if that is even possible.

Sorry, I know this is way outside the scope of this thread but after looking around various arduino websites my brain is literally exploding with ideas. maybe i should post something a little more relevant.... i'm thinking about starting with just making it a timer to control my halides. Would this be a good project to get my feet wet or will it be too ambitious?

I was thinking start with a timer and go from there because IMO the timer is the number one function of a reef controller, adding more and more functions as time goes on. Eventually adding controlling for my tunzes that coincides with my lighting schedule. I'm hoping to put the tank on more of a monthly schedule than daily or weekly. I want to have a simulated storm once a month with ALOT of flow and crazy light effects but also alot of really calm days as well with gentle up and down ramping of the lights. some days of course will be made brighter than other days.... :crazy1: oh jeez this owns me now.. and i'm rambling :o

ok i need to go :reading:
 
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oh, for sure! I saw a DIY arduino gameboy type thing at hacktronics or liquidware or one of those sites that i got a kick out of. expensive kit, but definitely VERY cool.

The coolest part is the flexibility, and the ease of use for people who aren't EEs. The Arduino hardware is really nothing more than an ATMega uc with some useful components thrown on - the real "magic" comes from the entire package (hardware, software, support, community).

After looking over alot of products and reading lots of beginner tutorials, i'm still pretty lost, though. This is probably a stupid question but, how many shields can you stack on top of a normal arduino (not mega)? and how many on mega? can a shield that fits on a normal board fit on a mega?

The short answer is: it depends.

Some shields are really weird physical shapes, or they're really tall, or they don't pass all the default pins through, which means you'd have trouble stacking them. Also, ANY shield is going to "consume" pins, even if it does pass them through, which means you need to plan ahead to be sure you don't have two shields trying to use the same pin. So there's no hard limit.

Plain Arduino shields are NOT by default "mega compatible." Even though the pinout is essentially compatible as far as the basic IO pins, some of the functionality build into the processors used on the two boards is available on different pins - I2C and SPI, if I recall. Luckily, there are some mega-specific shields out there, and many shields that aren't compatible include instructions for altering the hardware/software to make them compatible.

I have a beef with the "official" Mega board in that it doesn't even bring out all the pins in the 1280, so some of the functionality you're paying for is automatically lost. Luckily, some of the Mega clones (Seeedstudio's comes to mind) bring out the extra pins.

Another comment regarding the Mega - it essentially adds program memory space and more IO pins. There are relatively easy ways around both of those problems on the "normal" arduinos, so I don't see the Mega as inherently attractive.

I see that there is an SD card shield. Would that be easier than having it log data on a computer? I wouldn't mind pulling the SD card out and throwing it in my computer once a month to analyze the data. I would still want to be able to check what current params are though.

The SD card shield is really good if you need "unplugged" datalogging. For instance, MAKE (I think) had a project where they put temperature, humidity, and pressure sensors on an Arduino, then shipped it across the country. The Arduino took readings every so often and wrote them to an SD card. For an application like a reef controller, this would strike me as a really awkward approach. Better to just use a serial connection to a PC (through the USB chip on most Arduinos) or even better, throw on an Ethernet shield and put your Arduino on the web.

I also saw that there is a bluetooth shield or module that was around $20 IIRC (nope, it was more i was confusing it with GPS). I have a usb bluetooth dongle that works pretty well for being $2. I wonder if I can write a windoze gadget that can display everthing the arduino is doing/monitoring and have it connected wirelessly via the dongle. Tank is close enough for a long usb wire, but wireless would be better. maybe xbee would be better or ethernet shield connected to a wireless adapter, if that is even possible.

See comments above. IMHO, if you're looking for connectivity, an Ethernet shield is attractive, because it puts your controller on the network, instead of merely tethering it to a single PC.

Sorry, I know this is way outside the scope of this thread but after looking around various arduino websites my brain is literally exploding with ideas. maybe i should post something a little more relevant.... i'm thinking about starting with just making it a timer to control my halides. Would this be a good project to get my feet wet or will it be too ambitious?

The timer part would be dirt simple. Controlling the Halides means turning some really big relays on and off, and screwing with 120v AC - so proceed based on your own comfort level. Plus, it means the health of your tank is tied to an experiment. Perhaps a better first entry-level project would be a simple temperature logger. Connect a One Wire temp probe, a real time clock, and some means of data storage (or one of the above solutions) and have it tell you the temperature of your tank.

IMHO, other than waiting till we finish this project and just copying it, or copying someone else's finished project, the best approach is to start small, with something that won't put your tank at risk.
 
Since this design is for the larger community, what should we call it? I've been trying to think of a creative name for a while but I'm coming up blank. Any ideas?

I'd like to respect the Arduino core team's guideline to not use the word "Arduino" since we aren't officially part of their project. Also, I'd like to respect that they've stated they think naming something by tacking "-duino" onto the end of some common word sounds like crap. :D
 
Thanks for the reply.

Another comment regarding the Mega - it essentially adds program memory space and more IO pins. There are relatively easy ways around both of those problems on the "normal" arduinos, so I don't see the Mega as inherently attractive.
is that what the extender shield would be for?

Ethernet shield is attractive, because it puts your controller on the network, instead of merely tethering it to a single PC.

That is wonderful but I can't run a wire from my router all the way to my fish tank. Is there a wifi shield? Maybe I could get a cheap-o router, install DDWRT on it and set it up as a bridge. would this work? It'll end up costing me about $100 in parts to do that including the shield. I had considered this but i was hoping to do it cheaper.

The timer part would be dirt simple. Controlling the Halides means turning some really big relays on and off, and screwing with 120v AC - so proceed based on your own comfort level. Plus, it means the health of your tank is tied to an experiment. Perhaps a better first entry-level project would be a simple temperature logger. Connect a One Wire temp probe, a real time clock, and some means of data storage (or one of the above solutions) and have it tell you the temperature of your tank.

maybe controlling the fuge light, which is just 4 crees on a cpu heatsink, would be better. monitoring temp sounds like a good starter project too though. do they sell a waterproof temp sensor?
 
is that what the extender shield would be for?

People have made a TON of shields and breakout boards for extending IO capabilities. Usually it's an I2C port expander chip, like the MCP23008. Or, a PWM chip like the TLC's from TI.


That is wonderful but I can't run a wire from my router all the way to my fish tank. Is there a wifi shield? Maybe I could get a cheap-o router, install DDWRT on it and set it up as a bridge. would this work? It'll end up costing me about $100 in parts to do that including the shield. I had considered this but i was hoping to do it cheaper.

There's still a million options - zigbee radio to a dedicated Arduino that you can network or plug into a computer, for instance. There are also wifi shields:

http://asynclabs.com/wiki/index.php?title=WiShield_1.0

Or, you could get a "gaming adapter" made for converting an ethernet plug into a wifi client - they're sold for use on xboxes, etc. Probably cheaper than DD-WRT'ing a "real" router.

maybe controlling the fuge light, which is just 4 crees on a cpu heatsink, would be better. monitoring temp sounds like a good starter project too though. do they sell a waterproof temp sensor?

Yeah, then at least if they don't come on, or get stuck on, you're not putting your corals at risk. Most people that use temp sensors end up doing something creative to waterproof the sensor themselves - do some searching on the other Arduino reef projects out there and you'll get tons of ideas.
 
cool, thanks.

Since this design is for the larger community, what should we call it? I've been trying to think of a creative name for a while but I'm coming up blank. Any ideas?

I'd like to respect the Arduino core team's guideline to not use the word "Arduino" since we aren't officially part of their project. Also, I'd like to respect that they've stated they think naming something by tacking "-duino" onto the end of some common word sounds like crap. :D

Maybe something with mythology, Poseidon? is that biting off neptune too much? aquarius? maybe the latin name of a fish or something. latin for water control is compos aquarius .. just throwing things out there..

maybe an anagram would be cool
 
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More or less on hold at the moment. I have two other prototypes out to a board house (LED driver and ELN shield) so I'm going to get those nailed, then pick this back up. Hope to be ordering prototype boards for this in two or three weeks.

If anyone experienced at PCB design wants to look at the EAGLE project and comment on how I have it laid out, lemme know and I'll put it up somewhere.
 
I'm trying to teach myself basic electronics and circuit building. That's why I love this thread.
One of the things with teaching yourself though is you sometimes have to ask a question that may make you look dumb. So be it: here's one.

I never read/heard of "shield" before this thread. Is a shield just an industry name for a board with components built on it, or is there a deeper meaning?

Thanks.
 
Arduino people use 'shield' to mean a board that has a set format such that the headers align with the headers on the Arduino main board. That way the signals are passed from one board to the next. The 'shield' can then be stacked on each other with each using only the signals it needs.
 
One of the things with teaching yourself though is you sometimes have to ask a question that may make you look dumb.

Tell me about it. :lol: I'm also essentially self-taught. I had an interest in the electronics hobby as a teen, but hadn't really touched the stuff in years when I started recently dabbling for this fishtank stuff. So for every halfway-intelligent post I make in this thread, I've probably asked a dozen stupid questions. :lol:

Fishman, I missed your request above. I'll put it up soon and post here.
 
Thank's Fishman (maybe Fish for short?), appreciate it.

I thought it might be specific to Arduino, cause they were the only reference I found using it. Great to know

Thanks, DWZM.
 
http://www.pjrc.com/teensy/

Anyone else seen this? It's cheap and it solves some of the problems we'd have to solve (extra PWM pins, extra digital pins, etc) but obviously isn't shield compatible and doesn't have all the extra stuff we're putting on. . .

Too bad the AVR chip it uses is only availabe in a freakish package.
 
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