Must-haves for EASY DIY controller?

[TheShadow]

Sorry folks I have to post something before I can PM Joined RC because of this Thread love it so far thanks for all you people are doing

 

[der_wille_zur_macht]

To order boards, go to the google code site mentioned earlier in the thread and download the gerber file zip. This set of gerbers are formatted for seeedstudio and iteadstudio, so if you are using them to make your boards, you can just use the gerbers right on the google code site. Go to the web store for whichever vendor you're using and look at their instructions for how to buy the boards - it's a little different per each vendor, but basically you'll be putting an item in your shopping cart and checking out, then emailing the gerbers to a specified address.

If someone is using a different vendor to get the boards, the best course of action is to get that vendor's CAM job (or at least look at their production rules) and generate your own gerbers. Or you can try just emailing them the gerbers from the site and hope for the best (if there is anything blatantly wrong they'll tell you).

 

[SpacedCowboy]

This is really starting to look good, guys. Well done to all concerned

I hit a milestone myself today - finally getting the ethernet-based sensors to talk to the network I really wish you guys hadn't taken 'Hydra' as a name - it fits really well with the way I envisage mine working out, although 'spaghetti' might be a more-appropriate description at this moment in time [grin].

Anyway, just wanted to say congrats. It's amazing what reefers can do when we put our minds to it

Simon

 

[der_wille_zur_macht]

Thanks Simon. I like the name Hydra too. It's a multiheaded aqueous beast. Though yours definitely is, too! How about Medusa? That covers the spaghetti angle.

 

[terahz]

Here you go guys. Live from my tank: http://reef.geodar.com/

I have a webcam that also streams, but I'm not allowing that to everyone, at least for now, because I need to come up with a way to relay the data and not point everyone directly to the camera. My upload speed is not high enough to support more than 2 ppl viewing.

The above is a very early version. I'd say it is still Alpha state. The small graphs show the last 30 minutes. The gauges, the current value, and when you click on the "Show More" link under the given metric, it shows all available data in the database. I have cleaned my DB 2 days ago, so the historical data is quite short for now.

Few interesting things to observe. The "dips" in the room temp and cabinet temp are due to opening the window for fresh air . The PH drop this morning is due to cooking all morning...

The DS18B20 sensors are much more stable over long wire (digital signal, after all) so I changed all my temp probes' LM35s with DS18B20.

 

[der_wille_zur_macht]

VERY cool!

 

[fillibar]

I figured there were good reasons but wanted to make sure and not just assume I understood it.

 

[5ft24]

Very nice, TeraHz!
Can't wait for my board and parts to get here!!
do you have any samples of your sketches on the google site?

 

[shirley386]

I just ordered 10 boards from Seeed Studio. I need three and it looks like the rest are "spoken for". My cost looks like a little less than $5 per board. I'll keep you posted as how this comes out.

 

[terahz]

5ft24 the code is not on the google site yet because it is not the official firmware and is somewhat custom for some of the hardware I have on my controller (like relay board, IR sensor for remote control etc).

That being said, I've posted it before and here it is again:

Main AVR: http://svn.geodar.com/hydra/branches/prod/
Slave AVR: http://svn.geodar.com/hydra/branches/Slave/
Netapp: http://svn.geodar.com/hydra/branches/NetworkApp/

The only thing missing is the DB schema for the netapp, but if someone gets to that stage, let me know and I'll post it

 

[DustinB]

I'm out of town right now but I just noticed someone was asking about the gerbers.

DWZM: You might want to check those gerbers over real quick to make sure I didn't forget to upload some new ones since we found out about the U11 silk layer problem. If not I can check when I get back in town in a couple days.

 

[der_wille_zur_macht]

I corrected that problem and a few other small silk changes and uploaded new files back when we found that U11 was wrong, so we should be all set.

 

[NelsonPJ]

The DS18B20 sensors are much more stable over long wire (digital signal, after all) so I changed all my temp probes' LM35s with DS18B20.

Very cool web page!

Out of curiosity, how did you mount and wire your DS18B20 temperature sensors? While waiting to build my Hydra board, I've experimented with an Arduino and a DS18B20 sensor to monitor tank temperature. I tried mounting the temp sensor in a short piece of stainless steel tubing I bought from a hardware store, then filling it with epoxy. Unfortunately I noticed the "stainless" tube starting to rust after a couple weeks, so I quickly pulled it out of my tank. So now I'm looking for another idea. I was thinking about using small plastic test tubs from old aquarium test kits.

And about wiring - did you use the "parasitic" mode (two wires) or the full-powered mode (3 wires)? I've read that the 3-wire mode is more reliable, so that's what I used in my Arduino setup. Did you wire all sensors to the same bus? Are they wired in series or a "star" pattern, etc?

 

[nauticac4]

NelsonPJ

Look around on the internet for titanium tubes or 314 series stainless. The iron content is alot less and they shouldn't rust on you.

I have just started playing with the 1 wire setup on the temp sensors but haven't gotten into multiples just yet.

 

[terahz]

The sensors are in standard powered mode. parasitic requires that the data pin is high long enough to charge the caps. That means you can't use the bus for other communication.

As for water proofing, I just cover the IC and exposed bare wire with silicone. Seems to work just fine.

 

[5ft24]

Try these... Already waterproofed, sealed, using stainless (314) and have a nice cable
http://cgi.ebay.com/Digital-Thermal...174?pt=LH_DefaultDomain_0&hash=item3a61a158e6

 

[ludnix]

A little expensive for probes, but they sure are professional looking. I think I'll have to get couple myself.

 

[der_wille_zur_macht]

Try these... Already waterproofed, sealed, using stainless (314) and have a nice cable
http://cgi.ebay.com/Digital-Thermal...174?pt=LH_DefaultDomain_0&hash=item3a61a158e6

Tried one, didn't like it. Struck me as lower quality than apparent in the photo and I question if the steel used will be safe longterm.

For now I like the silicone or epoxy encapsulation method. It is cheap and effective. The only potential drawback is that silicone and epoxy are great insulators so your temp reading is going to be "slow."

When using these sensors in non-submerged environments (i.e. measuring temp on a heatsink or in the stand) I would leave the sensor itself exposed and just insulate the leads with heatshrink.

 

[der_wille_zur_macht]

A little expensive for probes, but they sure are professional looking. I think I'll have to get couple myself.

They are essentially the same price (or even slightly CHEAPER depending on packaging and quantities) than buying raw DS1820 probes from a place like Mouser or Digikey.

 

[der_wille_zur_macht]

PS - I like (and use) the DS1820 but I'm not convinced it's the be-all end-all temp sensor for our purposes. Besides terahz, I'm interested to know if people have experimented with other options. The DS1820 is expensive, and the resolution isn't super good. I wonder if there is a cheaper alternate with better resolution.

I'm building an I2C-based breakout board that has a second instrument amp (for another pH probe or ORP) and three ports for analog input, so I may try other analog solutions to see if I can get better results than terahz did.