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.

@Wolli01 These batteries are only good for medium to low power consumption. They are rated at ~1500 mAh, but only at 100Ohm load = 30mA. My first impression is, that these batteries are too weak. Anyhow, Better go for batteries with a higher voltage like this one: https://www.conrad.de/de/p/saft-ls-14500-spezial-batterie-mignon-aa-lithium-3-6-v-2600-mah-1-st-651153.html, or use three AA sized cells with 1.5 V each. If you scan through the forum you'll find a lot of discussion about power consumption and power budget. The power consumption of the ESP32 is pretty high by itself, and the WiPy need comparable long to start, consuming high power during that period. Other Pycom devices need more power and longer start-up time. The baseline Arduino UNO with its 8 bit Atmel processor at 8 MHz takes ~5 mA at full speed, compared to ~30mA for the ES32 w/o WiFi and up to 250mA peak/100mAaverage with wifi, @160 MHz clock speed.

@Martinnn said in Please help me! Micro USB card to my Lopy and Wipy: The adafruit board you referred to is simply a breakout board for a micro USB connector. The ESP32 does not have USB hardware, so there's nothing to connect it to... If you want to connect to (the serial port of) the Wipy via USB, you need a USB to serial converter. Easiest is to buy an interface board like the expansion board. Thank you

@protonx I made myself a base board too for the Pycom modules. A Kicad sketch is here: https://github.com/robert-hh/Pycom-baseboard It uses pre-built modules for USB/Serial and SD card. I did not want to deal with SMD parts, and space did not matter. It also has the espressif logic for activating the bootloader, and jumpers for the connection to Reset, Tx, Rx and P2. Not that this costs less than an Pycom expansion board, but it makes fewer troubles when using (no PIC, standard drivers, ..)

@robert-hh Eh yeah, I'll give that a shot.

@NickBoots , If you are connecting to an Access point from your pycom device (i.e Wifi in STA mode) disable the wifi on boot option via this command pycom.wifi_on_boot(False) reset board and try again.

Figured out the issue. Looks like the FiPy was consuming more current that my USB was able to deliver even though it was just running the sample PyMakr code of changing LED color. I connected a LiPo battery to it and didn't have an issue since. For those interested in figuring out how I got to this: I removed the FiPy module from the PySense Connected through USB to the computer and checked device manager for a new COM port If present, then PySense is fine. Without removing the USB to the PySense, I connected the FiPy and was able to program it. With the above basic steps you can determine if the board is actually bricked or just requires power.

@jcaron Yeah pretty sure it's in deep sleep at that moment. This +50mA is constant in deepsleep but also in normal state. So for example it draws 160-170mA instead of 110-120mA on the other LoPy with the same configuration and program. And in sleep it consumes 50mA while the other one around 0.215mA. It might be a simple mismanipulation but it's still strange that it's exactly 50mA. On the next prototype I will try to check the consumption before seding it as a test just to be sure.

@semireg Can we buy one?

@formica does any other ampy action work, like 'ls' or 'ls /flash'? and the usual brute force hammer on linux, running it with sudo?

@fsergeys I'm not familiar with Qi chargers, but isn't there a chance the electromagnetic field generated when you transmit data may "trigger" the charger somehow? Since those chargers are designed to be inserted into phones it shouldn't be an issue, but you never know...

Yes! Thank you!!

@robert-hh Thank you, that worked perfectly.

@livius It features a MAX3421E USB host controller chip and USB-A port. We created this board to communicate with existing serial-over-USB (CDC, or communications device class) devices. Adding support for other USB "drivers" is a matter of understanding the USB endpoints and writing the implementation in MicroPython. Update: Check out the First look: USB Host Expansion Board by Semireg

We are building a custom expansion board that will have a USB host port for bringing IOT to ordinary USB devices. If you message me I can keep you updated of our progress. First batch of boards are due to arrive next week. Update: Check out the First look: USB Host Expansion Board by Semireg

@soren Sorry for the late reply. Atom currently always copies the top option in the list. If there is an actual Pycom serial detected, it will place that one at the top. Anyway, this is just a result of your issue, not the cause. So just to be sure, after rebooting your mac, you are able to connect to your device? Then when switching out to a different lopy, the comport disappears from the list of serials, even when closing the connection during the swap? Do you switch expansionboards, or just the lopy? You could even hot-swap your lopy while keeping the expansion board connected, see if that helps.

Thanks for this information. Aparently I misunderstood documentation all those names are confusing at begining.

@robert-hh Thanks. it is working with 115200.