Hi all,
I am planning on trying to connect this DFRobot Arduino PH sensor to a gadgeteer board(DFRobot ph sensor for arduino - Gravity Analog pH Sensor | DFRobot Electronics) does anyone here have any experience with this kind of sensor and is it possible to do ?
Regards
You need 5V tolerant analog input. I am not sure if any GHI mainborad does have such a thing.
You can use voltage divider and set max input to 3.3V, but you will lose some resolution.
Atlas Scientific makes a pH probe kit that communicates with the MCU using a simple serial protocol. A little pricey, but it works great. I use it in my commercial applications.
Hi thnx for the reactions the problem is that the sensor is just for a hobby project so that is why the dfrobot sensor is a great option. But why could it not work ? i have seen that the gadgeteer sockets have analog input and 5v voltage available via an extender is it not just connecting the data wire to a analog connector ?
Analog inputs have different ratings, one can withstand 3.3V max, another 5V max and so on. I think I have not seen any GHI mainboard that has analog input rated to work with 5V.
Hi scardinale,
Could you maybe share how you connected the Atlas Scientific probe do have any pictures ? and do you have any example code ?
Regards,
Wim
@ WE - pay attention to this. Do not connect 5V to any Analog input on a GHI board. While they may (or may not) be 5V “tolerant”, it’s not a good idea to prove that tolerance.
However, you should be able to wire the signal line on the probe to any analog input on a gadgeteer socket. You’ll need some pH calibration solutions to calibrate it. ph 4 and 10 standards will do the trick. Also get a ph 7 standard to use for error checking. You’ll always see some drift around ph 7, but it should be within 5% if the quality of your probe is at all decent. Over time that calibration will drift as probe characteristics change, so always use the 4, 7, and 10 solutions to check. If it’s outside 5%, it’s time to recalibrate.
Looks like the Atlas probe comes with the standards.
Get one of the terminal block or breadboard gadgeteer modules and you won’t even need to solder.
@ WE, PM me with your email address and I’ll send you a NetMF Driver that I wrote for the Atlas pH Sensor.
Why not just upload it to CodeShare? You’ll get 500 shiny new points! 
Will do.