Openxsensor - Voltage Sensor Calibration

Development & General Chat for the superb openxvario project.

Moderator: rainer

Post Reply
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Openxsensor - Voltage Sensor Calibration

Post by Flaps 30 »

Finally go around to trying out the combined Current/Voltage/Vertical Speed sensor setup. All is well apart from the voltage sensor calibration. My arrangement consists of the 56K and 33K resistor (used to measure up to three LiPo cells) and it does work apart from a 200mV error. How or what do you change to correct this error? Is it done on the TX or is it a case of tweaking some numbers in the code?

User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: Openxsensor - Voltage Sensor Calibration

Post by jhsa »

Measure the exact values of your resistors with the multimeter and insert the numbers in the code..
Then if you still have an error, and if I'm not mistaken, a couple lines below you can insert an offset value in millivolts??

João
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: Openxsensor - Voltage Sensor Calibration

Post by Flaps 30 »

I will play with the numbers tomorrow. Couldn't find anything with regard to an absolute offset, apart from being able to tweak the reference voltage value on another page from the config file.

In a way this is an adjustment for Voltage and Current (FAS) offset that would be nice to have. Looks like Mike is onto it with regard to current offsets ----> http://openrcforums.com/forum/viewtopic.php?f=45&t=2321 In a way we have a lot of control over the zero current setting along with the slope in the config settings page. :)
User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: Openxsensor - Voltage Sensor Calibration

Post by jhsa »

Well, I'm using a quite old versiom of oXs and I can adjust all that ;)

Sent from my GT-I9195 using Tapatalk
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: Openxsensor - Voltage Sensor Calibration

Post by Flaps 30 »

Finally got around playing with the numbers. 33000 (33K) value in line 191 changed to 32300 (32K3) and the voltage indication came good.

The current sensor that I am using (ACS712 30Amp) worked well after the idle millivolts (line 115) was changed to 2490. The mV/A setting (line 116) was set for 66 as per spec sheet which worked out perfectly. :)

User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: Openxsensor - Voltage Sensor Calibration

Post by jhsa »

Good that it worked ;)
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW

Post Reply

Return to “OpenXVario - an open source vario supported by the open source firmwares!!”