Ok, I'll check with voltmeter before connecting it to the IOIO just to be sure..
Thank you very much for the quick reply in your busy day.. :) On Wednesday, August 9, 2017 at 1:08:21 PM UTC+7, Ytai wrote: > > I don't think the probe actually emits negative voltage. I think the table > is an example with voltages relative to some offset that the next section > describes how to measure. Essentially, you're doing a 2-parameter > calibration. > If you're unsure, connect a voltmeter to the sensor before connecting it > to the IOIO. > > On Aug 8, 2017 9:11 PM, "Maximillian" <[email protected] <javascript:>> > wrote: > > Hi All, > > I need to read pH using this product > > https://www.dfrobot.com/wiki/index.php/PH_meter(SKU:_SEN0161). > > I found this table on the description: > [image: Ph-mv.jpg] > > The table said that it will give negative voltage (0.00 mV to -414.12 mV) > for pH value 7-14.. > > I've been searching through this group, I think I found that I should not > feed IOIO analog input pin with negative value (only 0v - 3.3v CMIIW). > > I'm not really experienced with electicity, so any suggestion is really a > big help. > > Is there any solution for the negative value? > > Maybe using another componen to convert flip it to positive, > > or offset the voltage to be positive since it only have around 828mV range > (-414.42 mv to +414.42 mV). So maybe I can just set the 7pH from 0V to > maybe 2V, then the lowest voltage will only be 2V - 414.42mV, and the > highest voltage will only be 2V + 414.42mV > > or any better/proper solution? > > Thank you. > > -- > You received this message because you are subscribed to the Google Groups > "ioio-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > Visit this group at https://groups.google.com/group/ioio-users. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "ioio-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/ioio-users. For more options, visit https://groups.google.com/d/optout.
