Einsy Rambo Extra ports/ 3rd Thermistor?  

New Member

I have a MK3S, and I was wondering about the potential of the unused ports on the Entsy Rambo 1.1a:

EinsyRambo 1.1a main connections.

1) Could plug in a 3rd thermistor into the port between the heatbed and hot end thermistor connections?  I would Ideally use it to measure ambient temperature in my enclosure or perhaps mount it directly to the heat synch to monitor heat creep. 

2) Can I use the -5 volt (the one next to the reset button/endstop ports) to power my Pi 3 B+?  Am I safe to pull the recommended 2,5 amps through there?   Does that voltage cycle when I reset the printer from the control board? (I can test that on my own next time I am in there).

WHAT IS ICSP 32u2???  (The yellow pins next to the reset button/ LEDs).  Could I use this as an output to control a relay/servo/fan to vent the enclosure if the enclosure temp too high?

I know much of this could be done with the Pi alone, but I would like the exercise and elegance of getting every drop of functionality out of the mainboard. I also would like to get rid of the power supply without resorting to a buck converter if the 5v I need is already there. 

This is my first post here, and I did try a search if this was already covered, but if I missed something or I am doing something wrong please let me know.



Posted : 12/09/2019 10:46 am
Veteran Member Moderator

Hi Lee, 

ICSP is In Circuit Serial Programmer, it's for programming the processor at the factory before the USB is available. 
Running the RasPi off the Einsy regulator is likely to cause problems for your einsy and your raspi... there is not enough power available off the einsy.

I don't know about the 3rd thermistor, there are already 4 thermistors in use. 

Heatbed, thermistor, 

Hot end Thermistor, 

Pinda Thermistor

Ambient temperature thermistor https://forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-general-discussion-announcements-and-releases/ambient-temperature-sensor/#post-145925

do you really need more thermistors?

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 13/09/2019 1:35 am
Eminent Member


Can I run a fan off the 5 volt port? If so does it need to be configured?



Posted : 01/11/2019 4:31 pm
Noble Member

A buck converter is what, like $2.00. Even cheaper if direct from China.

I run my 3B Pi off the 24 volt supply, and the Pi case has room for the converter. And fan.

Don't use your Einsy for this. Folks gripe at me enough for using the PSU. (works fine for me)

Posted : 01/11/2019 5:46 pm

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