Current Sensor - shown in QGC

[axelnied]

Hi,

I am interested in getting "consumption" data into the QGC...
What are my options and what parts would I need to make this work?

I am using a Spektrum DX8, they offer a separate current sensor for around $45, to display the consumed mAh in the display of the TX. Nice, but not exactly what I am looking for.

Does MavLink data allow for current data?

[Max]

Yea, Mavlink does have a standard message type with a battery current field. It's part of the SYS_STATUS message, IIRC. The problem is where to get the data and then how to inject it into the status message that AQ currently sends. Since AQ doesn't have a current sensor onboard, there would need to be a hardware add-on, which somehow communicates with the AQ, and some code in the firmware to do the communication and send the current measurement via mavlink. Or some way to send a mavlink message directly from the current sensor (probably not very practical). The AQ does have a number of interfaces/types that can be used, so perhaps there is an existing off-the-shelf unit that can be fitted.

There is also the option of estimating current flow based on voltage and a known discharge curve... the AQ code does a bit of this already, and there are instructions in the docs about how to profile a battery so that the AQ can run a better estimate of the battery state. But this would obviously be less accurate than actual measurement.

Cheers,
-Max

[LPR]

Max

I already have one of these current sensors. http://store.diydrones.com/APM_Power_Mo ... apmpwr.htm

My octo has two batteries so I'll just use one sensor X2

Larry

[axelnied]

[kinderkram]

Wouldn't it be better anyway to monitor the current draw at the lipo directly, instead through the FC?
Some users who use 6s and/or power their boards through UBECs would be doomed in that case.

Next question: how do they feed the data to the APM's?

[axelnied]

[LPR]

The sensor for APM is connected between the battery and the main harness so it can read all current used. It connect to a plug on the board and the value is then sent to the Mission Planner.

I'm sure someone will come up with the FW mod to use a current sensor like Arducopter's.

Larry

[axelnied]

I took a look at the AQ board and could find some I2C connectors...
Would that be the way to go, with a sensor like this!?


only US$ 10...

EDIT: ugh forget it, only takes 3amps... Little low!? But I am sure there are other I2C sensors avail?

[chschmid]

I am afraid it measures only a few amps but we need 100A measurement.
Maybe we could use
Maybe Mr. Isler will give us the protocol.

Best

Christof

[kinderkram]

That'll be a nice bob but unfortunately it can only measure up to 3,2A.
Other units measure up to 90A