DIY DIY EC Meter

[donkeykong]

quick update, the DIY probe is all dried and ready to go. Thankfully we had some scorching weather so it helped to cure the potting compound. Left it a couple days to harder then turned it over and sealed the other end too, so now it should be waterproofed good and proper.

The probe I had ordered from RS got delivered to some random last week so I had to call them and get another shipped, which I have now. Looks good, so now I have a couple probes to start thing with.
Next Im working on the controller and testing the EC measuring circuits. I have another one in the simulator which I think will be better so im putting together the hw I need to compare and test.
Touchscreen made it here also, so needs interfacing the micro controller and some software to drive it, that will prbly take a few day to get going.

Heres the two probes I have to work with for now ;

 

[Groff]

Badass project!!

Will rep you as soon as I get to my laptop, and def joining the fun. I've long wanted to learn arduino but have near zero electronics knowledge and very low programming skills

(because I never got into it. First program I wrote was in BASIC back in ohohoh 1991? First http web page was written in windows 95 word pad loool - but since never again)

I know I able to produce something useful once I get my hands dirty, and this thread might just be the ticket! Would you recommend an Uno rev3, or something else?

 

[donkeykong]

Hi Groffuwiwi !

Glad your enjoying it, should be lots more to come!

I have a friend, more than a few years older than me, tells me about the first micro's when they were around and how they coded things into punch cards !! And lately I been talking to him about Arduino and how easy it is to get into and do something meaningful with ! Arduino makes the coding quite easy, and the best thing is there is LOTS of tutorials, examples on how to achieve a particular thing, its a well supported open platform. I went with the Mega2560 since it has lots more IO , 50-something IO's, lots of ADC input channels, PWM outputs etc etc. I hope I can connect to everything I need ! If you want to just get started any of the platforms is fine to learn with and probably has enough IO to do some cool stuff with. You get quite a lot of different "stackable shields" that make it dead easy to do something without needing to make electronics HW. EG you stick a relay shield on top, or LCD shield, or sensor shield etc etc.
Im doing it the way I am cos there is no such shield and I don't want to end up with 20 little boards stacked atop each other


So far the I2C comms bus is used to connect to a digital temp IC, reading the board temp, also on the I2C bus is the LCD. I have just this eve been wiring in a better display , 3.2" touch screen. The SW for that will be a bit more tricky but worth it.

First time I used one was about a year ago now, had a need for work to log the voltage of 40 lines (20 test equipments on soak for failure...). I was gobsmacked that I basically had it up and running the fist night. I used external 8 channel ADC chips, 5 of them all connected to the arduino. Guesse what there was a library for that chip already available and it made it very easy to snap a voltage from any channel, all channels continuously. Okay it took another 3 days to wire it all up properly in a box, but the SW part was quick and easy. I was expecting a few days of head scratching trying to set flags and registers to make some ground, but it took no time at all. Awesome.

I've mounted some connectors on a big veroboard so the arduino sits on it face down. Makes it easy to connect to all the pins. This main PCB I will attach the various EC test circuits to this later. Wiring the LCD up was a bit of a job and to get to the extra pins of the Mega2560 I had to make a hole through the board (those pins for some reason are not on the normal veroboard alignment like the others)

I've got a project box for this stuff to start living in soon. Decided to go with 4-pole DIN connectors on the back to connect to different EC probes, I will post pic later as I come to building that part.

 

[Groff]

I think I want to get into arduino ASAP haha... will try to do something basic too like temperature hydrometer data logger.

What do you think of this kit? Its a clone, and it seems about half the price for a full genuine arduino starter kit.

http://www.ebay.es/itm/Arduino-Star...mputing_Networking&hash=item1c33599e76&_uhb=1

 

[donkeykong]

looks good to me! there are quite a few clones I saw available, I've got a spare "mega2560" on the way from sainsmart.
nice kit put together like that, its all the basics to get you up and going including some breadboard, jumpers etc etc. Pretty good for the price.
Compatibility with the official hardware should be full, since its an open source design.
there looks enough stuff there to get your head around arduino a little and then you can add whatever you wish later, humidity, temp many sensors options.

 

[Groff]

Awesome! Thanks buddy! Just checking my balance to take the plunge... in the meantime, I'm all popcorned and subbe'd !!


:smokebuds:

 

[donkeykong]

Hi Guys...

Been busy putting something useful together, will be handy when testing and developing the sensor circuits. its a split rail power supply , delivers some nice clean outputs at +5V , +12V , -5V and -12V. Useful when you are driving op amp circuits that need split rail supplies. Also can power 5V loads, like the touchscreen I have. Powering off Arduino's built in regulator caused it to heat up a lot, the LED backlight on the display I saw drawing 0.5A , pushing the arduino's regulator.



I put this circuit together to do the job, maybe someone will find it useful reference one day

 

[lowbudge]

maaan youre kickin' it!

 

[Red eyed c]

Very interesting project bud.:thumbs: subbed in :smokebuds:

 

[OOOGaUtO]

Good stuff, wish there was a DIY ph meter! Great job bro