Hi, I would not recommend powering through Vin with a battery and USB at the same time. As the 5V from the USB will start charging your battery connected on Vin. When connecting to the battery terminal, there is a detection circuit that switches the power source of Vin between USB and battery to not put 5V on the battery lines.

Just to give feedback, I've had the Pytrack + Gpy powered via the VUSB_AUX for a few hours and all is working fine. Thank you for all the help!

@jcaron Thanks, I will keep that in mind !

https://docs.pycom.io/.gitbook/assets/l01-pinout.pdf says: 3V3 pin: Supply with a stable 3V3 power source capable of delivering at least 650mA

@abhishek2101 Go to the profile of the person you want to chat with, and in the middel right there is a circle with some dots. If you open that, teh first topic is: start a chat.

@anhphuong This seems to be the wrong forum for your question. You should go to https://forum.polymake.org/

@SiMoS-IoT Thanks. Given the state of Pycom documentation and the large quantities we are going to need we have decided to build our own solution, so the power feed issue will go away. I really like the approach to power Pycom have, but the fact we can't get any documentation on how it functions, other than a few system calls, means we can't take it into production. I'll probably still keep using it, but only for interests sake.

@protonx Look at : microsd-power-consumption-on-expansion-board-pytrack-pysense-etc "Conclusions to save power during deep sleep with Expansion Board : it is important to use only TX/RX jumpers, or else we will have extra 0.06 mA; large voltage values implies some extra (e.g., 0.02) mA; avoid using uSD cards, because even just inserting a uSD card, not mounted, without open files before deep sleeping, there is an increase in deep sleep current, depending on the type of uSD, e. g., extra 0.21-0.24 mA for a 8GB uSD, extra 0.12-0.14 mA for a 32GB uSD."

@curtis-hendrix I have no spec but I once tried to connect a small LCD display to that power pin. That was an instructive failiure. Even 400 mA is optimistic (may only be reachable at the limit of 5.5 V Gpy supply). You can safely use that 3.3 V pin to supply some I²C chips but nothing that needs power.

@james-matthews Depends what you mean by "idle". In Pytrack-assisted deep sleep it should be somewhere in the range of 10-20 µA. Once you wake up the ESP32 and/or radios whatever the Pytrack uses is drowned in the consumption of those. Note that in my experience, keeping the accelerometer active for wake-on-fall/tap/movement already brings power draw to several hundred µA rather than a few dozen as expected (but that was on the Pysense, and I haven't much investigated the cause for the issue since). I expect the GPS to be a lot more power-hungry, though there are probably standby modes and the like.

To anyone using the Bell Canada LTE Cat M1 network: just got word from them and it seems that at this point there is PSM support but: "eDRX feature is under consideration for future availability but there is no announced plan yet". I'll be playing with the +CPSMS AT command to see what's possible.

@jcaron With version 1.14.0.b1 I get 1.6 seconds.

Don’t know all those modules nor whether the data is correct, but it is my impression that they are mixing “pure” NB-IoT modules (modems, basically, which would require and MCU to control them, which would in turn add power consumption) with full systems like Pycom’s which include both the modem and the MCU (ESP32 in Pycom’s case), so it’s a bit apples and oranges...

@PaulM You might want to look into firmware version 1.19. At the moment it is still in beta, but it adds the option to use LittleFS instead of FAT as the primary filesystem of the internal flash. This prevents data corruption even in the case of power loss during write operations.

@bmarkus said in do you know the RF parameters of lopy?: LoRa Calculator tool Thank you, I will try it, but I want to know the values of the parameters mentioned, maybe you can give me them if you have it. thank you

Hi @turbolego Power consumption will vary with usage, you can find all the details on the datasheet: https://docs.pycom.io/chapter/datasheets/downloads/fipy-specsheet.pdf

I did some measurements of power consumption a few months ago, when i started working with a FiPy + Pysense board. Back then i could measure around 7.5 mA in Lightsleep mode, when disabling all antennae and such. Since then i haven't been measuring current. But my current program that i have running on the Fipy consumes (with all connections / antennas disabled) around 35 mA, when i did a measurement today. This is due to having the SD card inserted (not mounted) as far as i can see, because when i remove the SD card i measure 7.5 mA again... Can this really be correct? It's much more than what is described in this thread, has anyone gotten similar results? In an older thread, @jmarcelino wrote that simply inserting SD card uses 5 mA, but that's still nowhere near what i am seeing! https://forum.pycom.io/topic/3097/power-consumption-issue Edit: I think i have a broken FiPy, since the same code on another FiPy measures around 7.5 mA, which is what i expected. I also tried the one i suspect to have a fault on another Pysense board, but it still measured 35 mA in Lightsleep, also after flashing..

@SiMoS-IoT I improved the way the GPys were handling network failures and ended up implementing a function that manages delays between retries. So if the device can't connect it keeps waiting longer and longer to save power... Delays between attempts : {1,1,1,2,2,2,4,8,16,32} in minutes. You get the idea. Unfortunately I had to ditch all pycom boards for now and find an alternative solution. We faced major issues about 9 months ago, and did not get a prompt reply/support. See this thread: https://forum.pycom.io/topic/3390/potential-device-lockdown-network-providers/37 The Sequans modem is (STILL) not supported by Telstra : https://www.telstra.com.au/content/dam/tcom/business-enterprise/machine-to-machine/pdf/telstra-m2m-certified-devices-modules.pdf

@kbman99 This INA169 device is also interesting, because you can set the sensitivity yourself with the appropriate shunt resistor. But the INA219 device @timh mentions is even more interesting, since it takes both voltage and current, and avoids the noisy ADC of the ESP32.