I’ve put a 'scope on the 3V3 line. Without the 100uF capacitor I can see its voltage dropping to 2V2 causing it to reboot.
With the 100uF capacitor I can see that every 60ms the line drops by about 680mV, 3 times in quick succession. This is not enough to cause a reboot. When it gets a GPS fix and sends a spot I see the 3V3 line oscillate (~900mVpp) until the tracker reboots. The oscillation is at about 40kHz so it doesn’t seem to be pickup from the LoRa transmitter.
There is no droop on the input voltage to the regulator or at the battery.
The datasheet for the CE6260B33M regulator specifies the dropout as 120mV @ 100mA and 650mV @ 500mA. But the issue here is its ability to deal with a sudden increase of output current. Increasing the output capacitor is obviously helping with that but seems to cause instability.
I notice that @CA2RXU used an electrolytic, @M0JKS used a ceramic and @MW0PDV used a large tantalum. I wonder if the ESR is critical or if 100uF isn’t actually quite big enough.
So I’ve tried a 330uF electrolytic and the 3V3 line is sagging about 500mV. When it transmits I see the line oscillating but the tracker does not reboot. So I’m unsure if the oscillation is pickup or regulator instability, but the capacitor seems to be large enough for the tracker to keep working.
I’m not sure if I can get the 330uF cap in the case so it would be good to know if, for example, the 100uF ceramic definitely works.
The Heltec apparently uses and ESP32 S3FN8, VDD3P3_CPU needs to be at least 3V.
The GPS on both boards seems to be powered by a seprate LDO to the ESP (T Beam uses 2 outputs from the AXP2101, Heltec looks like it uses 2 seperate CE6260 regulators).
The UBlox 6M on the T Beam uses slightly more current than the UC6580, but not much more.
There could be typos on the datasheets, and the actual boards may use different chips (especially if not genuine).
M0MZB-15 shut itself off early this morning due to low battery…with a power consumption of 14mA in eco mode, and three 18650 batteries I was expecting much longer, despite fog preventing and solar charging this week.
It has switched back on this afternoon.
I would like to query the unit, to see if it is in eco mode…my none of my messages get through.
I can successfully message other iGates using APRSDroid (sending vua tcp/ip) but my messages don’t seem to get sent out any further. The aprs system doesn’t seem to pass my messages onto RF from a nearby igate, to reach M0MZB-15.
I am sending from Aprsdroid with callsig6 M0MZB-7.
Any suggestions? Can anyone else reach M0MZB-15 and query the eco mode status?
Both the Peak District digipeaters are down (presumably) for the same reason. When I recover mine I’m going to install a daylight switch to limit operations to daylight hours only.
Could it be that the M0LLC-10 iGate (I can see your message sent back to APRS-IS from this iGate) is not configured to gate messages to RF, or it’s using a filter that excludes messages? Or perhaps even that it is not configured to TX to RF at all?
I’ve had my Heltec wireless tracker with 330uF capacitor sitting on the desk. It appears to have been working fine until the battery went flat. I’ve plugged the USB in and it is now in a reboot cycle - it starts and then immediately sends a spot at which point it reboots. It’s odd that this is happening with the USB plugged in - I suspect that when the battery is fully charged it will work ok again although I don’t know why this should be the case.
With the last few days of misty weather MW0PDV-14 is almost holding its own but it is slowly discharging.
Although I am running a 4G router with the igate, I thought the 40w solar panel with a 65Ahr lead acid leisure battery, was overkill for a load of between 100 - 300mA. The solar panel is facing more west of south than I really wanted and so losing some efficiency there.
I think this is the way to go, certainly for winter months.
the ecomode is 21mA (SX1262) and 25mA(SX1278) LoRa Module consumption
how many packets will it transmit? the more it repeats the less it shows the lower consumption benefits to the non ecomode.
to query the digi an igate has to be able to get to it and should at least listen to it once 30 min. If this is not achieved it wont relay packets from APRS-IS to RF and therefore it won’t get to the digi. NOTE: digis also answer to direct RF to RF queries if you have line of sight of it
Yes, this is my experience using Dave M0JKS’s unit with three x 18650s (no solar) - around 72hrs or just a bit over.
Ref querying the digipeater, I did some reading around this as I admit that I have no experience, but what I did read shows that for messaging to work, a lot of things have to fall into place - this is an interesting piece: APRS Messaging EXPLAINED! - APRSISCE/32 The future of Amateur Radio APRS
I connected to my igate M0MZB-10 via the TNC using an application called PinPoint on my windows machine…and sent directly over RF. At the same time (strangely) I seemed to magically get DroidStar to communicate over the internet by igate’d my packets to RF via M0MZB-10…not sure if its a coincidence, or if I suddenly woke something up!
Nice to get it working though and confirm that M0MZB-15 is indeed still running in EcoMode
