WiPy pin 3V3 not work?



  • Hi,

    when i attache 3V3 to 3V3 pin (i have checked that 3V3 is on output from UART/USB converter)
    as below then board not work

    0_1479932112928_upload-78a49153-250c-4dde-9113-5109b2bb60b3

    when i restore connection to VIN(5V) like below all work

    0_1479932213870_upload-9a776b05-0a5a-48e6-96e6-7684fefd95b7

    any hint?



  • a) WiPy consumes a substantial peak current when sending. That may be for a few ms only each time, but that makes it even harder for a power supply, because the impedance has to be low and the regulation speed fast.
    b) I prefer to take the 3.3V pin as an output and would always supply it through the Vin pin. Then the internal power regulator ensures a proper supply.



  • maybe thats it
    i still not have replacement 3V3 with power e.g. 1A - when i got it i will back



  • BTW: From the documentation (not sure if it was there before):
    "When powering via 3V3: The input voltage must be exactly 3V3, ripple free and from a supply capable of sourcing at least 500mA of current"



  • @Frida
    the jumper is ok - i have checked the voltage on the converter

    @littlebat
    maybe thats it, i read on seller 250mA but have not check specification by myself
    i must test it with distinct power 3V3 not from converter



  • Ch340 built in ldo can only supply 25ma. Not enough for esp32. 5v comes straight from USB so it is enough.



  • It seems you have to move the jumper to pin 2-3, instead of pin 1-2.
    Use a voltmeter to check the voltage on pin 3.0_1479943519305_pic02.png



  • The 850 uA figure is just in suspended mode for WiFi and with the processor sleeping I believe. The ESP32 data sheet says that it can actually draw up to 225 mA when transmitting WiFi. With the LED etc. I would add some more. So your converter must be able to supply that. At least if the WiFi is enabled. And I guess some headroom would be helpful as well, I guess those are just average figures, short peaks could probably be higher. At least that is the case with the ESP8266...



  • Yes i want to power WiPy from converter.
    It work if i connect 5V from converter to 5V VIN WiPy input Pin
    but not if i connect 3V3 from converter to 3V3 WiPy input Pin

    --And are you sure that the converter can produce enough current
    What current? WiPy2 consume 850uA if documentation is true here.



  • And are you sure that the converter can produce enough current? Many cannot... If you have another power supply which delivers exactly 3.3 V and can deliver the necessary current, you could retry that.



  • Hi @livius,

    If I get it correctly, you want to power the WiPy with the converter?
    Are you sure you are connecting to a Vin pin and not a Vout?


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