Problem Random operation of the USB connection

edited October 2019 in Repetier-Server
Hello,
I still have trouble connecting with the pro server ... This morning, I turn on my prusa MK3 and repetier is working properly and this afternoon, the connection does not seem to work .... Once again, I reinstalled the last image rpi 0.92.2, (why is not there the last image rpi in 0.92.3?) on my side the update in WIFI does not work and crashes as usual. I feel that the USB connection does not work (the rpi port is disabled on the Prusa). I do not know what and I'm a little tired of fighting with unstable versions. what should I do again this time? At startup I have ports that scrolls that did not show up before. What to do to have the USB connection?
I tried to change USB cables, change the USB ports on the RPI ect ...  I specify that when the re-i stallation completes the connection works but if I turn off the printer and the server and then I restart it does not work anymore



Comments

  • as you can see the thunderbolt sign at right upper corner you have unsufficient power for the raspberry pi.
    that causes instabilities , i use repetier server myself since 0.86 Version up to 0.92.3 now without any problems.

  • the overcurrent change seems to be the problem. One or more of the usb ports draw more current that allowed/available.
    Not sure with the flash symbol - normaly it indicates undervoltage but might also signal the overcurrent. Normally dmesg shows undervoltage messages as well.

    So unplug all components and reboot and see if the messages go away - might also be something internally connected as usb device.
  • edited October 2019
    I use this adaptater to conect the RPI and the screen : https://www.amazon.fr/gp/product/B01NAQ15C9/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

    It's a problem ? You think my rpi is over powered ?
    Is it possible to have the latest version 0.92.3 in raspberry image ?
    (on the RPi I only have my USB C920 camera connected and the port of the einsy prusa, My 5-inch screen is offset by cables dupont but the screen is powered by this adapter 5V, it can also ask pb ?)
  • That power supply is limited to 2.4 amps max per output, so yes it is under powered.

  • MartinH said:
    That power supply is limited to 2.4 amps max per output, so yes it is under powered.

    You confirm that it takes 3A output is it ?
  • That is a usb charger. You need a 3A power supply. From electronic side that makes a big difference - a power supply is supposed to hold voltage up to max. current. Chargers are allowed to drop voltage/current. Some chargers may work when they have better electron also made for stability but power supply is what you need. Such wrong power supplys cause probelms with lan, wlan, mouse, usb connected devices and much more and are a known problem.

    Only thing stange is overcurrent warning. Normally you get undervoltage as said. Overcurrent means the usb device is drawing more then the allowed 500mA. Might be related as well meaning device has not power for the current you draw, but never had that problem so no experience.


  • Repetier said:
    That is a usb charger. You need a 3A power supply. From electronic side that makes a big difference - a power supply is supposed to hold voltage up to max. current. Chargers are allowed to drop voltage/current. Some chargers may work when they have better electron also made for stability but power supply is what you need. Such wrong power supplys cause probelms with lan, wlan, mouse, usb connected devices and much more and are a known problem.

    Only thing stange is overcurrent warning. Normally you get undervoltage as said. Overcurrent means the usb device is drawing more then the allowed 500mA. Might be related as well meaning device has not power for the current you draw, but never had that problem so no experience.


    Thank you for your clarification because today I received a USB charger 5v 3A and on the screen I still have the message of undervoltage, I conclude that the charger drops in voltage as you told me ?
  • I guess so. Chargers do not need to hold voltage as stable as power supplies. They are made for more or less constant currents and the pi changes power quickly depending of load, active peripherals etc. That is at least the reason I read. Some may be good enough to work but is pure luck. I have one where it seems to work also I see undervoltage. Warning of undervoltage comes early so not always it disconnects everything or only parts I did not notice.
  • edited October 2019
    Repetier said:
    I guess so. Chargers do not need to hold voltage as stable as power supplies. They are made for more or less constant currents and the pi changes power quickly depending of load, active peripherals etc. That is at least the reason I read. Some may be good enough to work but is pure luck. I have one where it seems to work also I see undervoltage. Warning of undervoltage comes early so not always it disconnects everything or only parts I did not notice.
    Actually I'm a little confused, most of the adapters that have found in the trade are born 3A but in reality they are all 2.8A ... If you have a reliable link of a charger really delivering 3A I want to test. 
    My current charger is announced 3A but it comes out 2.8A so I have the logo and the undervoltage warning
    Maybe a charger for rpi 4 (5.1V 3A) would fit better for my rpi3B + ?? What do you think ?
  • Having tried many foods that are not satisfactory in terms of undernourishment, here is finally a diet that respects these promises 5V and 3A :
    https://www.amazon.fr/gp/product/B078Y1MSPX/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
    Now I have no problem booting and I do not have the little yellow logo of undernourishment !
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