Thanks,
The first one works quite well now, but it continuously spits out the reading every few milliseconds:
6.29
6.59
6.64
6.66
6.66
...
The second one gives me this:
54 6
46 .
51 3
49 1
13
54 6
46 .
...
I saw on the datasheet that the sensor could be calibrated using one of the various commands.
The solution I am testing the probe in is a pH 7.00 (@25C +/- 0.02) and the readout I am getting is only 6.66 ( it goes up to 12 when I test with pH 10).
I tried using the serial monitor to input these commands, but nothing happened...