I hope that I understand the situation correctly:1) MAVlink protocol has a message type that includes a slot for reporting mAh remaining in battery.2) HK-GCS does not utilize the mAh information, so the very nice widget for reporting battery status only responds to battery voltage and battery capacity does not change with time.3) HK-GCS has a place (and widget) for showing battery amps, but MAVlink does not have a message type with a slot for that data, so HK_GCS has to show battery current as constantly zero. This is not the fault of HHK-GCS; it's not being supplied with relevant data. Hopefully a future MAVlink protocol update will at least provide battery current data in a message so that it can be displayed by ground stations.I found these things out (courtesy in large part to Doug Weibel) when I added a current sensor to APM 2.12 and found that no ground station is able to report battery capacity remaining or battery current. Only APM terminal shows battery current and capacity.At the moment, I'm thinking of adding a work-around by modifying the APM 2.12 code so that I can select (via an RC channel value) whether the battery_voltage variable is filled with actual battery voltage or battery current or mAh before it is sent to HK-GCS. A kludgy way to multiplex that data, but it will probably suit my usage well enough.
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I agree that there is no MAVlink field for current, but the "battery remaining" field is working for me in APM 2.12 and seems to be reported properly in HK GCS 1.2.96. "Battery remaining" is transferred as a percentage of the capacity entered in APM (i.e. if you have used 200 mAh and the capacity was set to 2000mAh it will return 90%.) The HK GCS mAh counter then scales the value you have entered on the settings/instruments page by the percentage parameter. I see the bar and numerical value coming down as I use more of the battery.
In 2.11 there was a problem with the scaling in mavlink_common.h that meant that the parameter was too low by a factor of 100, so it was always reporting back less than 1% remaining, but this was corrected in 2.12
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I agree that there is no MAVlink field for current, but the "battery remaining" field is working for me in APM 2.12 and seems to be reported properly in HK GCS 1.2.96. "Battery remaining" is transferred as a percentage of the capacity entered in APM (i.e. if you have used 200 mAh and the capacity was set to 2000mAh it will return 90%.) The HK GCS mAh counter then scales the value you have entered on the settings/instruments page by the percentage parameter. I see the bar and numerical value coming down as I use more of the battery.
In 2.11 there was a problem with the scaling in mavlink_common.h that meant that the parameter was too low by a factor of 100, so it was always reporting back less than 1% remaining, but this was corrected in 2.12