i intended to buy some capsules, but since the first one does not run longer than 60 minutes… i wont 
(they promised some weeks of runtime
i buy here: the newest versions, just have to wait some weeks for it…
this might be a nice tracker:
just seal it waterproof somehow, maybe even change the antenna for internal.
Ive been playing around with the Heltec Wireless Tracker board, and so far it is quite impressive for a ESP board. Im testing it as an alternative to the RAK Cow tracker setup Ive posted further up.
It does use about 3x what a RAK with a gps module uses when looking for a position, but when sleeping it uses close to nothing. This is actually very desirable as for my 6month tracer over 60% of battery capacity is waisted during standby.
High Values for the Heltec is not accurate as my mutimeter is a bit messed up at the moment.
RAK: Aquiring position 75mAh, transmitting 120mAh ish, sleeping 1mAh
Heltec Tracker: Aquiring position and transmitting aprox 200-250mAh, sleeping less than 0.01mAh.
For a long period (weeks-months) tracker with update every few hours the Heltec is actually a very good alternative, but for short period (hours-days) with fast update rate the RAK is to prefer, as you can use a smaller battery compared to the Heltec. For a dog tracker it is actually better to run the gps without sleeping as it gives a more precise position and you need faster updates.
Position aquirement is from my short test period with the heltec almost the same. The faster the update rate is, the quicker it will aquire a position.
Heltec: Update Every few minutes aprox lock time is 15seconds, update every hour 30-45 seconds.
Again this is VERY dependent on location and GNSS signal strength. The heltec will struggle to get a lock indoors.
One thing I havent had a chance to check with the RAK setup is the claim that the sleep current will also drop to almost zero when the battery voltage drops bellow a certain point. From what I can read it is the Voltage regulator has a loss of 1mAh, and this will drop when the voltage requires less “regulating”? Kilroy, have you any data on this?
And I am still hoping the Meshtastic team will re introduce the GNSS lock timeout function so we can save even more battery power when unable to lock the gps signal.
i have also only read about the 1mA and less thing on rak devices.
have not tested myself.
i am very interested which heltec board you used, which meshtastic firmware and settings !?
is it this board: ?
https://de.aliexpress.com/item/1005005681504175.html
i did not get any of my esp32 devices to sleep 
Many thanks for the link Kilroy!
i updated my heltec capule to newest firmware XX.14 stil not sleeping. just rebooting cycle …
Kilroy, yes its that board, heltec tracker V1.1. Ive put the latest stable FW on it, I beleve its 2.3.12.
Same setup as on the rak, Tracker mode with power save enabled. Set gps pos. update, pos transmit and Telemetry transmit with the same interval, so it will sends battery status at the same time. Guess one could set the same for temp and other Telemetry if one want that as well.
Hi all, I am new to this channel but see I am on a path already forged by others. A lost dog a few months back prompted me to dust off my hardware skills and try to build a pet tracker.
I settled on buying two Heltec Tracker V1.1 devices, and am rolling my own software. However the first issue is getting the GPS to lock on. I am starting with the Wireless_Tracker_V1_1_FactoryTest example, but the satellites never lock on. I don’t think the GPS is defective since the behavior is the same on either device. I have tested this indoors, outdoors, and both with and without the supplied antenna, and also leaving the device connected for 60 minutes outside.
I am at a loss for how to debug/fix this. Other hardware (Adafruit Feather w/ GPS Featherhat) works fine. Any suggestions?
You need to look at the characters the bare GPS is putting out, they tell you whether its got a position lock and the signal strengths of the GPS satellite signals it receives.
This is a simple test program for T-Beam, it echos the GPS characters to the Arduino IDE Serial Monitor. You would need to adjust the GPS RX and TX pin numbers for your Heltec;
#define GPSRX 34
#define GPSTX 12
void loop()
{
while (Serial2.available())
{
Serial.write(Serial2.read());
}
}
void setup()
{
Serial2.begin(9600, SERIAL_8N1, GPSRX, GPSTX);
Serial.begin(115200);
Serial.println();
Serial.println("14_GPS_Echo Starting");
}
Thanks for the reply, StuartsProjects, and I see a lot of characters go by and it does have UTC time parsing. So it is “talking” to satellites but not locking. Below is a snippet of the characters:
$GNGGA,132300.00,,,,,0,00,99.99,,,,,,*7B
$GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,1*33
$GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,2*30
$GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,4*36
$GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,3*31
$GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,5*37
$GPGSV,1,1,03,14,,,23,24,,,22,19,,,17,1*6B
$GPGSV,1,1,01,14,,,18,8*60
$GLGSV,1,1,04,75,13,030,23,76,53,085,,77,40,158,,,,,26,1*48
$GBGSV,1,1,01,65,37,125,,1*46
$GBGSV,1,1,01,65,37,125,,5*42
$GAGSV,1,1,02,40,06,260,,43,33,238,,7*79
$GAGSV,1,1,02,40,06,260,,43,33,238,,1*7F
$GQGSV,1,1,02,42,37,125,,50,46,140,,1*61
$GQGSV,1,1,02,42,37,125,,50,46,140,,8*68
Next ideas to try as hobby time permits:
- read up on GPS signals to understand the $G lines
- an external active or passive antenna
- flash with Meshtastic instead of example GPS code
- switch from USB to battery to see if power is interfering with signal
GPGSV is the useful one, it tells you the strength of the satellite signals. The sentence above has data for 3 satellites and the blocks of data are;
14,?,?,23
24,?,?,22
19,?,?,17
The ? are missing data which happens if signals are weak.
The last numbers in the block, 23,22 and 17 are the satellite signal strengths and those values are very weak signals indeed, it might never get a fix, the strengths need to be above 26, and probably 30 to get a fix.
Poor antenna on the GPS maybe.
More info here;
https://stuartsprojects.github.io/2018/10/01/My-GPS-does-not-work.html
@StuartsProjects Thank you again for the encouragement, and I am happy to say I got a satellite lock (whew!).
I flashed my Heltec Tracker with Meshtastic, added a battery, using the internal GPS antenna, plugged in the lora antenna, and left it running at the edge of the house (externally powered also). This morning I saw that several satellites had locked on. I don’t know how long it took to get the lock - it could have been hours.
So the antenna was seemingly poor either in design or in manufacturing since it should not have been this hard. I had tried it outside for an hour before but it had not worked; this was before the lora antenna was added so I wonder if that contributed to my trouble.
Your 10/2018 blog article is well-written and insightful. Also kudos to the Meshtastic solution. I’d still like to write my pet-tracking solution, but using Meshtastic to show proof-of-concept and working hardware is helpful.
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Problems with GPSs are normally fairly basic.
If the GPS is working, and with a decent working antenna, is outdoors with a good view of the sky, it should get a location fix in around 45 seconds from power on.
If the GPS takes a lot longer to report a fix, then it either in a bad location or the GPS or its antenna are just not good enough or are faulty.
I’ve been fiddling with the heltec capsule a lot the past few days.
Not had much success with the latest firmware for it. Runs fine and gets gps pretty quick but won’t sleep.
Modded the variant file for the wireless tracker firmware and uploaded that to the capsule and now have the power saving open. Spend ages working out the CLI options and a solid config, but soon as I switch it to Tracker role it starts sending GPS every 2 minutes and think its boot cycling. Will try the sensor role tomorrow and see if I have more success.
i uploaded 2.3.14
and i am seeing some kind of boot cycle too, instead of sleep, it reboots…
Follow-up: I wanted to share my solution for a pet tracker based on the Heltec Tracker V1.1 chips.
This project was my excuse to purchase a 3D printer (Creality Ender 3), and I used OpenSCAD to design a case for the the Heltec device, LiPo battery, user/reset buttons, and antenna. There are four corner holes in the case that are used to add elastic to connect the device to my dog’s harness.
Initially I started writing the software myself, but after stumbling across Meshtastic I gave up since the Meshtastic firmware is excellent. Someday I may try to add color support to Meshtastic, since the interface could be so much better with some splash.
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Serpac has some nice waterproof enclosures in a dog wearable size. Just not sure how you would incorporate an on/off switch and port for charging.
Do you have the STL file for that case or did you download it elsewhere?
Ye, seems an interesting device.
Not sure if have much details what sort of battery life gets with the Meshtastic firmware. That article was testing LoraWan, and didnt seem to do extended tests.
The flat form factor, perhaps not ideal for all but the largest dogs. wouldnt really attach to collar.
The more think about it wonder, if worth developing some ‘minimal’ Meshtastic firmware for tracking devices. A much simpler firmware, that pretty much doesnt nothing but wake up periodically, send a ‘Position’ packet, and go back to sleep.