Pat, I'm replying to this via email instead of privately on TRF because I think the answers are of general interest to our customers, and thus I want to CC our mailing list. Hope you don't mind!
> I noticed that when I accessed the EM via AltosUI, the battery voltage > reported is about .5 volt lower than the actual voltage of the lipo. There are two things going on. The first is that EasyMini v1.0 units with purple circuit boards like yours have a design glitch, in that the voltage measurement is actually at the input of the LDO *after* a blocking diode, not on the battery itself. This means the reading will always be a fraction of a volt down from what you read at the battery terminals. We corrected this for the batch currently under assembly that will be on green circuit boards. For some reason, we failed to bump the version number, so both purple and green boards will be marked v1.0 but purple have the bug and green are good. [sigh] The second issue is that we aren't sure we got the ADC conversion coefficients right on EasyMini. Keith will investigate this as soon as the new (green) batch of boards arrives, to make sure we're reporting the right voltage on the corrected board design. That may result in a firmware bump, we'll report if so. > Second (disconnected from Altos), when I turn on the EM, it reports > Startup, Pad, and then continuity. It does not report the battery > voltage. So, on the pad, when the EM is powered up, I won't know what > the voltage state of the lipo is? > > Is there a firmware update that will provide a report of the lipo > voltage? Great question. Just hasn't come up before since all our other flight computers have radio telemetry. Keith says he'll add voltage reporting to the EasyMini startup beeping. We'll report when that's done and new firmware is available. The plan is to report two digits so you get tenths of volts. > On your next version of the EM, you might consider (if possible > without increasing power consumption too much) an increase in audio > volume. As it is right now, the EM beeps away for over 2.5 hours on a > 110mah lipo..... nice! Still had a reading of 3.90 volts on the lipo > at that time. The audio volume is constrained by the combination of our choice of beeper and the fact that we're operating at 3.3 volts. We use the same beeper on all our products that have one because it's the best I've been able to find so far. The same beeper is louder on 5V, but that doesn't help us. I haven't found a small beeper that's louder, but I do check our suppliers from time to time hoping something better comes along! If anyone knows of a better beeper, by all means let me know! Hope this helps. Bdale
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