idea: Tx Running timer / power meter

[wilco1967]

Is there somewhere in ER9X a timer, that runs as long as the 9X is powered up, and can be manually reset to zero ?.

I'm thinking that might be useful to give an indication of how much time is left on the 9X battery. We need to (manually) reset to zero on a full charge (maybe possible to automatically reset, if the voltage has suddenly risen since last use).

The low voltage alarm is good, but the discharge curve of most batteries is pretty flat, so offer not a good indication of how much charge has been used.
The Surefire cells I'm using, last something like 10+ hours, so I cannot remember actually how long I've run them since last charge....

Perhaps even a (estimated) mAh used counter (which needs some calibration settings, depending on actual hardware used). Perhaps even considering the time the backlight is turned on.... just some thoughts.... Not a real meter, but just an estimation in software:
mAh used = running time x 9X power useage constant (without backlight) + time backlight on x backlight (only) power useage constant

Something similar was done on MultiWii powermeter.

Just a timer would be sufficient.... mAh is just 'nice to have'....

[MikeB]

There is a timer on the STAT screen at the top called TOT. This shows the total time since the tx was turned on. Currently it cannot be reset. THe problem with tracking the total on time is it needs to be stored in EEPROM for when the tx is off. We can't store this as the Tx is switched off, so it would have to be updated continuously while the tx is on. If we write it every 10 seconds, to keep a reasonable resolution,then we will wear the EEPROM out in 1,000,000 seconds (100 000 writes at 10 secs each). This is 277 days of power on. We also need to decide where in the EEPROM to write it, if it is put in the general setup file the whole file will be updated every 10 seconds which will impact the functioning of the tx.
It may be possible, but will need careful thought to avoid wearing out the EEPROM too quickly.

Mike.

[jhsa]

When the audio project for the er9x is complete maybe you could write that file to the SD card used for the audio files

João

[GyroGearloose]

Simpler idea would be:
- just record the voltage whenever it rises (aka you've charged) and assume that's the max "full" voltage.
- compare that to the "alarm" voltage, and show it as a simple percentage and/or nice battery icon.

So, if my LiFE battery charges to 10V, alarms at 8V, and I'm currently at 9.5V, we know I have "75% Tx battery remaining"

I'd really like to see a similar thing for the flight battery as well... TH% timer is great, but it would be more logical than "variable speed time" if the underlying percentage could be exposed to the UI... 2:30 out of 5 minutes of "squishy time" that actually takes 6 minutes wallclock time is a lot easier to understand if just shown as as "50% flight battery remaining".

-Gyro

[MikeB]

For the flight battery, if you fit a current sensor, and feed it into A1 or A2 FrSky telemetry, you can now get mAh used displayed on the 9X screen.

Mike.