Pull-up/down resistors for endstops?

Root Controller
1

Hello

I have bought a Root Controller ISO rev3 and it looks very good. It is already working with my motors. Now I am going to install NC endstops. However I have a doubt with the switches and I am worried because I have already brick a controller from another manufacturer because of them, probably due to the lack of pull up/down resistors. I have seen in the wiki that you can directly connect voltage free switches, without the need of resistors. But, in the config.yaml configuration file, is it necessary to activate the internal pull-up/down resistors? For example: limit_neg_pin: gpio.34:high:pd or limit_neg_pin: gpio.34:low:pu

Thanks in advance,
Alfonso

2

Hi Alfonso,

Glad to hear you’ve got your motors working!

Good news - There is no need for any external Pull up resistors on the Root controller - this is done internally within the root controller. Additionally, there is no way of bricking the controller if you wire it in incorrectly. You can short V to GND which will blow the internal fuse (which is replaceable) but this will not brick your controller.

The software used PU and PD to denote when a signal is inverted or not - this has no bearing on the hardware. so if you have your endstops triggered, when in fact it is not. then swapping this parameter around will solve this issue.

I hope that helps and I’ll add more information to the Wiki.

Kind regards Pete

3

Hi Pete,

Thank you very much for your help. Everything is working fine. Congratulations and thanks again for your work.

Regards,
Alfonso