Welcome! Log In Create A New Profile


Radds 1.2v - Compatibility Issues

Posted by BigRepRap 
Radds 1.2v - Compatibility Issues
April 08, 2015 10:30AM
Hi all!

I was just thinking on acquiring a radds 1.2v in conjuction with an Arduino Due however I was not entirely sure of some of the aspects around radds.

Ramps 1.4 includes different 12v non-controllable for fans, I could not find such connections on the radds 1.2v, although the fans could be plugged directly to the main supply, I was wondering if they could be connected to the board.

I've seen different methods for auto-bed-levelling, for my application I cannot have an end stop attached to the extruder so I thought about using inductive sensors (Ultrasonic sensors; see the link bellow) can those be connected to the AUX ADC port on the board? if not, could you please guide me where it could be connected ?


The Radds comes with can protocol pins that could be used for a feedback system as well as encoder pins for the same usage, has anyone attempted to design a feedback system on radds?

Thanks in advance
Re: Radds 1.2v - Compatibility Issues
April 08, 2015 11:13AM
All the 12V connections for hot ends, heated beds, etc should be 12V hot all the time. It's the ground that is switched. Just use one of those screw terminals for a fan if you want fused protection and then the main supply ground as your grounding point.

That sensor has a range of detection of 5cm-3mm. That may mean that it's precision isn't all that great so the point where it closes may not be consistent. It's also a PNP sensor so you'll need a voltage divider on the sensor output to drop the voltage down to 3.3V. Instead of a PNP I suggest looking for a NPN NC version which won't require the voltage divider and makes for a simpler setup. That price is very high. If you don't need ultrasonic, you can get a inductive or capactive proximity sensor on Amazon or Ebay for a fraction of the price of the sensor you linked to.
Re: Radds 1.2v - Compatibility Issues
April 08, 2015 11:45AM
The problem with using an ultrasonic sensor is that the speed of sound varies with temperature, and this affects the height that they sense quite significantly. So they work OK when the machine is cold - especially if you apply compensation for the ambient temperature - but not so well when the bed is heated. I used to sell one, but gave it up for a better solution using two beams of infrared light.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
Sorry, only registered users may post in this forum.

Click here to login