@robert-hh said in Li-ion battery discharge: bq24040 All of our boards use the same bq24040 circuit, therefore it is recommended to use batteries with a PCM to protect the battery from over discharge

Thanks for the replies! @robert-hh It might be that the program is not burnt onto my LoPy. I ran the uos command and this is what I got: ['main.py', 'sys', 'lib', 'cert', 'boot.py']

Sorry, I misunderstood. I can only tell you that the Pygate mounting hole spacing is the same as the Expansionboard 3.0's spacing. We provide that here: https://docs.pycom.io/gitbook/assets/specsheets/Pycom_002_Specsheets_Pygate_v1.pdf in section 12. I will work on getting the Expansionboard spacing out there on its own page!

Could you use a battery and inductively charge the battery?

@seb Thanks a lot for quick response!

@derchris said in LoPy broadcasting network: thank you @seb @bmarkus Alright, I misunderstood the device classes, so I guess Class-A is fine. Current (remember, newbie, but I have to start somewhere) is a LoPy as RX-only client and using a Laird Sentrinus Gateway for Multicast. TTN shows a blog post about OTA DFU here https://www.thethingsnetwork.org/article/firmware-updates-over-low-power-wide-area-networks/ and I think this is something I can take some ideas from Thats a very interesting read, this relies on the same trick @bmarkus suggested where all devices use the same IDs and keys to be able to receive the same messages.

@jcaron Thanks for your reply. 1.) I would say everything below 5 seconds is acceptable. 2. / 3.) This question is hard to answer, since I will try the device with different types of applications so the capacity of the batteries will strongly vary. The battery life should be as long as possible. I also found the machine.idle and machine.sleep in http://docs.micropython.org/en/latest/wipy/library/machine.html. Given the description machine.sleep should work if I trigger the LoPy through Wifi. Is that correct? Thanks in advance.

@robert-hh Things are much better now it's wired correctly! :-) The batteries and the converter have been at room temperature for the last few hours and my LoPy and sensor are working fine. Thanks again for your help Robert.

@aris Currently beacon scanning is done via GATT which adds a lot of stack overhead. It's possible to scan for beacons more efficiently.

@jcaron Isn't this the opposite of what what stated here: Not completely the opposite, it's still more efficient to use a regulated 3.3V supply (low voltage forces the onboard regulator into bypass ECO mode) But it needs to be updated to reflect that 3.3V should be applied to the 5V/VIN pin. Is the Pysense/Pytrack sending power to the module via 5V Yes, all the various shields implementing deep sleep control the *py board's 5V rail

The same USB cable works fine with all other LoPys so I don't think it is a problem related to the cables nor the USB ports...

@jmarcelino I solved it. I have used an old firmware version on my gateway. I guess I missed this one module when updating all others. After updating I can set the TX power up to 20 dBm without getting any errors. Thanks for your help! Kind regards Pascal

@littlebat It said max current 40 mA in the maximum ratings sections, but I myself did not trust that anyhow. Even if, the output levels then are somewhat off GND/Vcc. So 12 mA sounds much more convenient.

I had simmilar issue using VIN. I can't believe Pycom doesn't provide any schematic for these expansion boards, or atleast proper descriptions on how they can be used. I was also under the impression that VIN can be used as an input, instead of using the USB. There are NO WARNINGS anywhere that you should not be using VIN as an input, while using a battery as a backup. Luckily my house didn't burn down as I soon enough figured out that VIN and the Battery + seem to be linked together... I'm new to Pycom's hardware - and thus far really disappointed in the lack of usefull (and up to date) documentation

@bucknall thanks that is very reassuring. I am looking forward to when this feature is implemented. Kind regards, Chris

@chrisi Are you measuring over USB or on a battery? According to this post: https://forum.pycom.io/topic/1460/power-consumption-deep-sleep-pysense-pytrack/20 you'll get about 10 mA more over USB. Also, are you using the expansion board, Pysense, Pytrack...?

This was due to a change in the ESP32 IDF a couple of month ago. I've seen the brownout also in some C projects on the WROOM32. Make sure you can compensate when the MCU is spiking in power consumption by placing a big capacitor in the circuit. Google is your friend.

@bucknall ok, thank you! I had not considered that the pytrack hasn't extra female pins, so i think i'll start with a standard usb connection, because i don't want to have to solder, at least for now. I'll have a look at the lopy-raspberry code :D

Why would you want to run your device directly from a solar cell? You will need a much larger panel/ device and it will be extremely weather dependant. Stop torturing yourself and get a tiny solar charger and a lipo battery, and Plug this into the battery port of the board, and you are done!

@jmarcelino Thank you!!! you saved my day, it works!