BIGTREETECH SKR v1.3 - Reuse Unused PINS

The SKR v1.3 is an excellent 32Bits card, but lacks of multipourpose pins.

As the GPIO of LPC1768 is configurable, I would like to know if is it possible to reuse some unused pins from the card to other purposes than the original ones.

Thes connector could be the unused X/Y/Z min/max endstops, TH1, etc.
Saldy the UART pins for 2208 drivers are inaccesible (in case you have old dir/step drivers).


Edit: attached a list of pins and their functions (from [mbed.org])


I'm trying to use some of these pins as PWM Out for Case Light and HB (via external mosfet).


Cheers!
ePoxi

Edited 1 time(s). Last edit at 09/08/2019 10:59PM by epoxi.

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ePoxi

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Well you can forget about the endstop pins because they all have hardwired 10k pullup resistors.

I have repurposed the servo pin 2_00 to use for an inductive proximity sensor (because the 10k pullup causes it to not work on z_min), furthermore there are the stepper driver pins for Extruder1 and the thermistor for E1 that can be used. In the original schematics you can also see what the pins are capable of and what voltages they can handle.

Edited 2 time(s). Last edit at 11/15/2019 03:23AM by Ohmarinus.

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http://www.marinusdebeer.nl/

I am really looking forward to upgrading my DIY printer with this -

Setup:
SKR v1.3
TMC5160 for X and Y
DRV8825 For Z, E0 and E1 (dual toolhead printer)
BL touch for ABL

I need to connect a second servo for locking the printhead in place... But I only see one SERVO output - which I guess I need for the BL touch ?

On my OLD mks-board I used a D11 output and edited the marlin for this pin ?

Is there a way to connect more servos til SKR v1.3 ???

Thanks in advance!!

With your configuration you seem to have used all the IO pins that are easy to reuse.

No mention of a LCD but I presume you have one...

Two option
1) You can de-solder the pull up resistor on a unused end stops pins and then use that pin.
2) you can de-solder the resistor that joins TX and RX on ax axis that isn't used them, you can use these IO pins.

Quote
Dust
With your configuration you seem to have used all the IO pins that are easy to reuse.

No mention of a LCD but I presume you have one...

Two option
1) You can de-solder the pull up resistor on a unused end stops pins and then use that pin.
2) you can de-solder the resistor that joins TX and RX on ax axis that isn't used them, you can use these IO pins.

WOW thanks for the quick response.

I have the TFT24-v1.1 so yes i have an LCD haven't had it hooked up yet though. It seems funny that it has both EXP1 and EXP2 output, and two white connection options.. But I guess its for multiple uses (ramps etc.)

How do I know which resistor i need to de-solder, if for instance I would use my X+ pin 1.28 ??

And thank you.

Technical stuff. [github.com]

Look in SKR-V1.3-SCH.pdf X+ is connected to 10K pullup R5 which can be found on SKR-V1.3-TOP.pdf
You can also remove R6, but you must connect the two pads back together (use a 0 ohm resistor or a wire or a solder blob)

Edited 1 time(s). Last edit at 11/24/2019 04:30AM by Dust.

Gee Thanks a million....

Perhaps I could have done that on my MKS sbase v1.5.
Couldn't get inductive sensor working on because of the pullup...

I will give it a try!



Edited 1 time(s). Last edit at 11/24/2019 04:39AM by webberen.

I did the unsoldering, connected the two pads together with a brasspin - I then tried different changes in the pins file

// Servos
//
#ifndef SERVO0_PIN
  #define SERVO0_PIN       P2_00

#endif

#ifndef SERVO1_PIN
  #define SERVO1_PIN       P1_28

#endif
//
// Z Probe (when not Z_MIN_PIN)
//
#ifndef Z_MIN_PROBE_PIN
  #define Z_MIN_PROBE_PIN  P1_24
#endif

//
// Filament Runout Sensor
//
#ifndef FIL_RUNOUT_PIN
  //#define FIL_RUNOUT_PIN   P1_28(Undefined this, since it is the same pin)
#endif

It doesnt move at all...

I can send M280 P1 and it gets S91 return... But no movement with either servo or BLTOUCH on the P1 ??

Any help would be greatly appreciated

Hope you only bridged R6 and left R5 open. Picture of the board to show you got the right parts?

I guess that what I did wrong then...

I will remove BOTH R5 and R6 right ? End only reconnect R6 ?

#UPDATE!

It Works now !!!

THANKS A MILLION !

Edited 1 time(s). Last edit at 11/29/2019 06:26AM by webberen.

It looks as if you almost connected C5 with R6.

Edited 1 time(s). Last edit at 11/29/2019 11:19AM by Ohmarinus.

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http://www.marinusdebeer.nl/