LoRa APRS Tracker (Part 9)

What antenna is that?? sorry I may have misssed the post somewhere!

Thanks

Alan

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https://sotaloraaprs.miraheze.org/wiki/Antennas

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Hi Richard

I found another bug that affects this. There are two separate routes in the code to powering down.

  • One happens at the beacon interval and shuts everything down after sending a “sleep” beacon.
  • The second works from the main loop - this one doesn’t send any message and also forgets to turn off the radio. So if that one happens, you get a steady drain of about 12mA even when it shuts down. Not good for the battery …

I’m using LiPo cells and I will set my shutdown voltage to 3.6V in order to keep some buffer.

I have made a code change to remove this second version, currently testing, and will upload it to my github soon.

Cheers
Rick

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Interesting. I would have thought 3.6 Volts was too high. Incidentally your low power code doesn’t appear to work on the Heltec V3 board that many are using. The WiFi ap part is fine but when the “low power” option is enabled from the web interface, the LoRa RX doesn’t seem to work.

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any detailed info about it?

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Hi Richard

I’m unable to test that as I don’t have one, but my changes shouldn’t have made any difference

Rick

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Hi Ricardo

This change is this

  • In the main loop() there is a call to BATTERY_Utils::checkIfShouldSleep(). checkIfShouldSleep() does not turn off the LoRa Rx … I just commented out the call.
  • The code in Utils::checkBeaconInterval() and Utils::checkSleepByLowBatteryVoltage() checks the battery at every beacon transmission and this routine does turn off the LoRa hardware.

Rick

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I’m glad to inform that WebFlasher for LoRa APRS Tracker is now available for beta-testing (V0.9.8 ).

All boards should work right away. Enjoy!

https://richonguzman.github.io/lora-tracker-web-flasher/installer.html

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send me the link please :wink:

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Rick

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Hi Richard

I may be wrong : I had commented out a chunk of Heltec code that was getting in the way of debugging - I have now out that back, so maybe you could try my latest version ?

Regards
Rick

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is there a way to write you on telegram about this mods, looks awesome

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Will do. I’m away at the moment.

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Works like a charm!

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Hmm, think ill just use the Jpole i had planned to use! certainly in the short term anyway… at the home QTH I have height on my side!

Alan

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A matter of taste : 3.6V on a LiPo is around 15-20% depending on the cells - I’m using mismatched recycled vape ones that are probably best treated carefully.

Rick

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There’s an interesting trade off there between battery capacity and solar panel size (if that’s your application). I reviewed the discharge curves I used and it does look like your suggestion of 3.6 Volts might be a good choice at low discharge rates.

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Hi Richard

I’m experimenting with a 1.5W panel, which looks good so far for “super low power” mode
Will be using 5 mixed vape cells for around 6Ah capacity, so that should give ~ 10 days in the absence of sunlight.

It should be possible to make into a “single box” solution around 120x100x30mm - maybe with the antenna internal to the box ?

Rick

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Anyone know what the teeny tiny co-ax connectors are called the use on the Heltec ETC LoRa boards??

Thanks muchly!

Alan

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IPEX if I’m not mistaken

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