Very interesting projects.
I have one question though. It seems that my probe won't work on 3.3V VCC. On 3.3V the readings constantly fluctuate +/- .2pH on continuous measurement. On 5V it's just fine. Is there a reason this could be happening? I think it's like 1 or two things.
1. I'm using a USB hub to connect to my laptop to power the arduino and probe so there might not be enough power to run everything at the stated voltage.
2. My probe which was shipped from china is just inefficient.
In the event that it's a probe problem is there a way to step up 3.3V to 5V in arduino? I'm worried I won't have enough space to run everything. I saw this thing called a logic level converter but I'm not sure that's applicable in this scenario... I don't have a multimeter with me but I guess I could try plugging it into my DC adapter to see if it works alright.
Or alternatively is there a way to split the 5V into multiple connection points so I can run my LCD and my probe.
I've read that I can split it through a parallel circuit with any number of devices whose total draw is less than 1A so that I don't fry my components. Does that sound right?
Last edited by Jeffww; 01-28-2013 at 09:41 PM.