***Official Electronics Thread of Officialness (it starts off with lots of Nixie Tube Clock goodness

PhillyDee · 31 Jan 2013 at 10:03

I keep reptiles, and there is nothing for temp monitoring, so first stage is learn how to monitor temps with it, and post some output code so I can actually view it real time (or near as dammit) on graphs so I have a historical record. Stage 2 is hot and cold side monitoring of (currently) 12 vivariums (so 24 temp probes needed) and eventually more as I learn it. Tempted to use it to control temperatures as well, but I think I will keep seperate proven stats for the vivs, would hate for something to go wrong and cook the occupants!

GeForce · 31 Jan 2013 at 10:16

PhillyDee said:
I keep reptiles, and there is nothing for temp monitoring, so first stage is learn how to monitor temps with it, and post some output code so I can actually view it real time (or near as dammit) on graphs so I have a historical record. Stage 2 is hot and cold side monitoring of (currently) 12 vivariums (so 24 temp probes needed) and eventually more as I learn it. Tempted to use it to control temperatures as well, but I think I will keep seperate proven stats for the vivs, would hate for something to go wrong and cook the occupants!

Cool

Which temperature sensors are you planning to use?

Maybe eventually you could get an ethernet shield for the Arduino and post the temperature data to a web backend, then plot the graphs on a web page?

Glaucus · 31 Jan 2013 at 11:28

GeForce said:
So apparently there should be a pad on the shield somewhere marked "input", which you need to solder to one of the 5V GPIO pins around the edge of the shield. Then driving that GPIO high/low will enable/disable the relay.

Usual warning about mains voltage, please don't kill yourself
.

Thank you, easy as that, will give it a try and soon as post arrives (assuming the electronics pack arrives today) What are the other 6million pins for (I assume there just through pins for the other GPIO on the arduino? Do I need to connect up 5v/grd as well as input? Probably should just have a play.

Glaucus · 31 Jan 2013 at 11:30

GeForce said:
Maybe eventually you could get an ethernet shield for the Arduino and post the temperature data to a web backend, then plot the graphs on a web page?

This is exactly what I want to do(temp, humidity, light, moisture) not sure how to use this shield either.
Ha I feel so dumb.

GeForce · 31 Jan 2013 at 11:42

Glaucus said:
Thank you, easy as that, will give it a try and soon as post arrives (assuming the electronics pack arrives today) What are the other 6million pins for (I assume there just through pins for the other GPIO on the arduino? Do I need to connect up 5v/grd as well as input? Probably should just have a play.

It's just standard practice when designing a shield for the Arduino to bring all the pins through to the upper layer, so that further shields can be stacked on top.

The documentation for that shield is rather lacking on the web, but I imagine GND will already be connected and they leave the choice of the signal pin to you. Have a play, you won't damage anything. If you don't get anywhere with it, take a decent resolution photograph of both the top and bottom of the shield and I will take a look

Glaucus said:
This is exactly what I want to do(temp, humidity, light, moisture) not sure how to use this shield either.

This part is definitely more complex, ethernet is a bit of a beast. There's lots of stuff on the Arduino forum about using the ethernet shield. I imagine you'll just want to make a simple HTTP POST request or something to a web server, containing all your data you want to log.

Here's the documentation on the Ethernet library for use with the shield (the Client section is the one you'll be wanting):
http://arduino.cc/en/Reference/Ethernet

Glaucus · 31 Jan 2013 at 12:08

Thanks, annoyingly the relay doesn't have through pins (unlike the Ethernet which does), thankfully loads of non shielded pins on the mega 2560.
I shall save the Ethernet, till I have the sensors and relays up and running. But just want a website with a few line graphs on, tracking the data.

GeForce · 31 Jan 2013 at 12:18

Glaucus said:
Thanks, annoyingly the relay doesn't have through pins (unlike the Ethernet which does), thankfully loads of non shielded pins on the mega 2560.
I shall save the Ethernet, till I have the sensors and relays up and running. But just want a website with a few line graphs on, tracking the data.

Agreed, definitely just do one thing at a time.

As an intermediary step, you could have the Arduino plugged into your PC and relay data back over the serial port (over USB), and then bash together a quick python script or similar to read data from the serial port and write it to the webserver. Then later on, remove the PC from the equation and have the Arduino submit the data itself.

Let us know how you get on :cool:

Glaucus · 31 Jan 2013 at 12:39

Will do, will need more help anyway.

What I've learnt from buying the first batch of components, don't buy stuff that is confusing/lacks documentation.
Got a digital temp sensor, but it's confusing, got some nice simple tmp36 on the way, hasn't arrived today though

.

Some components have hundreds of tutorials, others have none. I should have checked this first, live and learn.

PhillyDee · 31 Jan 2013 at 12:58

GeForce said:
Cool Which temperature sensors are you planning to use?

Maybe eventually you could get an ethernet shield for the Arduino and post the temperature data to a web backend, then plot the graphs on a web page?

Apparently the TMP36 are pretty good, and they are cheap enough. See how I get on with those first. The hardest part is learning the programming, and how to pull, record and display the info! I know nothing about programming (well, I know bits learned at college programming PLC's, ladder diagrams and basic stuff, and I taught myself HTML but thats it) but since I have a goal in mind I shouldn't have many problems. I know I will need to multiplex the analogue inputs, and theres a couple of bits of info on t'internet about doing so. See how I get on

.

Glaucus · 1 Feb 2013 at 21:15

Could anyone explain this data sheet to me please? I'm so confused

Glaucus said:
Thanks, form that also saw these, but I can't do electronics. Can anyone explain the data sheet to me?

Why the 25 & 85c values?
On the relative spectral distribution chart, I assume those lines directly correspond with the relative K led?

I assume the jo (easy white at 85c) gives a minimum of 1040 lumens? But what is the watt draw for it?
And what's two step/4 step in the table?

http://www.mouser.com/ds/2/90/XLampCXA2011-29838.pdf

Glaucus · 1 Feb 2013 at 21:58

Also got the relay working, package of further bits haven't arrived yet.
But I cant get a DHT sensor working. Im getting this error?
Its code from a tutorial so don't understand why its not working

lord filbuster · 1 Feb 2013 at 22:14

Glaucus said:
Also got the relay working, package of further bits haven't arrived yet.
But I cant get a DHT sensor working. Im getting this error?
Its code from a tutorial so don't understand why its not working

I found that project, I'll try loading it onto my arduino, and see if i can replicate the problem.

ahh, there are some weird characters on line 1 of DHT.h. Delete the entire line and retype it. I think that should fix it.

Makhaira · 1 Feb 2013 at 23:02

Glaucus said:
Could anyone explain this data sheet to me please? I'm so confused

hanks, form that also saw these, but I can't do electronics. Can anyone explain the data sheet to me?

Why the 25 & 85c values?
On the relative spectral distribution chart, I assume those lines directly correspond with the relative K led?

I assume the jo (easy white at 85c) gives a minimum of 1040 lumens? But what is the watt draw for it?
And what's two step/4 step in the table?

http://www.mouser.com/ds/2/90/XLampCXA2011-29838.pdf

The 25 and 85C values are to illustrate how the characteristics vary with temperature. 25C is effectively at the time of switch on, whereas 85C allows for heating. Lots of devices vary their performance with temperature, so this can be useful information.

You've lost me a bit on the graph question - does the key not help?

The power draw will be VI=P. so 40 x 270x10^-3 = 10.8W

No idea on the 2 step/4 step I'm afraid, Google will be your friend there!

Glaucus · 3 Feb 2013 at 19:38

I'm thinking no, but is it possible to run to separate loops on arduino?

Basically, trying to do two different things. One is waiting from an input from the pc, the other is just a delay timed loop.

Makhaira · 3 Feb 2013 at 20:07

You absolutely can Glaucus, that's the principle of interrupts. Have a look in the manual for the one you have, there will be something in there detailing the interrupt capabilities of that chip.

RomanNose · 3 Feb 2013 at 20:08

Glaucus said:
I'm thinking no, but is it possible to run to separate loops on arduino?

Basically, trying to do two different things. One is waiting from an input from the pc, the other is just a delay timed loop.

Lookup interrupts, micro controllers don't have multiple cores so you can only do one thing at once.
What you can do is use interrupts, you can setup UART interrupts that will stop the main program and go to whatever code you need to do when you receive something from the computer.

Poolybit · 20 Feb 2013 at 20:34

d_brennen...

Did you happen to use the Sure 2416 display boards in your project? If you did, would you mind if I asked you a couple of questions?! I am trying to put an LED clock together from Nick Hall's instructions and I'm having some trouble getting the screens to...register any sort of life!

/edit Disregard! Got it working...issues with the ribbon cable!

d_brennen · 21 May 2013 at 14:26

Thread necro alert ^ They are indeed Sure 2416s. Lovely, lovely panels to work with, especially if you've had the pleasure of working with lesser panels! I'm designing a perspex case but I suck at CAD... BUT I HAS ACCESS TO A LASER CUTTER! Massive incentive booster that

Where are you at with the build? I've found Nicks code really buggy, took me a LONG time but I have the clock nearly functional with some nice features like dimming and alarm. Once I have this whale in the bag I going after an even more mind bending project - an 8x8x8 RGB LED cube, like this one

frying_pan_cat · 21 May 2013 at 16:22

I'm sorry if this has been asked before, but I'm looking to get into electronics. Could anyone recommend any resources for learning (I did some basic stuff in school but been out of it for a while), and also any inexpensive but interesting projects that could get me into it? I want to feel like I've actually achieved something as well as understanding how it all works

Thanks

Poolybit · 21 May 2013 at 19:55

d_brennen said:
[SNIP]

Did manage to get this working in the end (had forgotten about it as it has been a while!), did rewrite most of the code though. Also added a few functions myself, added a start up animation with a nod towards the classic 90's film Hackers:

And added another clock function which is a binary clock mode, took a while to get that one figured out! The flicking on the second changes etc I fixed in a later version!

I have to say I have had it sat on my desk unplugged for the past month or so, my missus keeps pestering me to get a case built so that it can go in the bedroom but I haven't found the time (and my woodwork skills are very below par!) I do have a case designed ready for some spare time (or my Dad to have some free time so I can palm it off to him as he is an ex-joiner!) which is going to be in light oak to match our bedside tables.

I also put in a dimming function after 2200 as on full power it does kinda light up a dark room! Did you ever design a proper PCB for this? I have a custom arduino circuit built on a breadboard to save using my proper arduino kit for it but every attempt to design a PCB has left me bewildered and confused if I'm honest!

I have now moved on to my next project which is a portable N64, slightly more ambitious than my last one but making some fair headway at the minute! Got the screen up and running hooked up to the N64, all running off of a single power source.