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bigtreetech / Rumba32

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Current capabilities of onboard voltages #2

Open Schild0r opened 3 years ago

Schild0r commented 3 years ago

It would be good to know the max current you can draw from each port and especially the onboard voltages For example:

  1. Maximum current that can be drawn from all combined 12V ports that are fed from the onboard regulator
  2. Maximum current that can be drawn from each port that can be fed from onboard 12V regulator (HE2, Fan0, Fan1)
  3. Maximum current that can be drawn from the RGB 5V port
dixi83 commented 3 years ago

Since BTT uses the same voltage regulators as other Rumba32 designs (I checked the the IC types on my btt board) you can have this as information: image

The mosfet information is here (also same IC's as on my btt board image

The RGB I cant tell, there is no information on the schematics of the other brands and I am unable to trace the route back it looks like a death end to me....

Hope is helps

dixi83 commented 3 years ago

I managed to trace the route it goes through this IC: image marked with "C25F" which lead me to this information: https://www.ti.com/product/SN74LVC1G125#product-details##params >> 32mA

So my first guess is it can control a WS2812 Pixel led strip! where the signal port can be used to transfer data to the WS2812 LED's. I have not checked it but here is more information: https://3dprinters.proboards.com/thread/21/neopixel-ws2812-ledstrip-light-printer

forget WS2812, look for neopixel led srips https://marlinfw.org/docs/configuration/configuration.html#rgb-color-leds

Schild0r commented 3 years ago

I managed to trace the route it goes through this IC: image marked with "C25F" which lead me to this information: https://www.ti.com/product/SN74LVC1G125#product-details##params >> 32mA

32mA? That is for the data pin right bc 32mA would barely be enough to drive a single LED. Thanks for this finding it will surely help someone but I was actually interested in the current capability of the 5V line on that port (don't know whether this is hooked directly to the 5V buck or if there is some other current limiting component in between) so that I can determine how many neopixel LEDs can be fed from this port (with worst case of 60mA per neopixel LED)

I also read that some boards are not compatible with neopixels at least in conjunction with marlin but I think that was a MCU limitation that does not apply to the STM32F4... That we have here.