Wiring Servo

2500ccm

Hello,

i need a Servo for my Tool0. Problem is all PWM Pins are used on the Duet2 Ethernet and the Duex5. On PWM5 is the Bltouch. Where i can get a Pwm Signal for the Servo. I thought Fan8 can have a Pwm Signal, but it is not possible.
Other idea is to use the servo and the bltouch both on pwm5 and made there powersupply switchable.

Maybe have someone a better solution?

Thanks Mo

Phaedrux

Do you have a free heater pin?

2500ccm

No. This would be the easiest way...

Phaedrux

What pins do you have free? Just fan8?

2500ccm

Sorry for the late reply. I had a lot of work to do.
Free are Fan 1 and 8. Pwm 1-4 have free sockets, but the heater sockets are used. Pwm5 have a bltouch connected.
Maybe use Fan 1 and 8 for switching the gnd or 5v of the servo and bltouch on/off. Then use the same pwm signal of PWM5? Is this possible?
Bltouch and the servo for toolchange is not often used.

DIY-O-Sphere

@2500ccm
An Sx1509+External Mosfet would be an option

dc42

@2500ccm you could use the FAN1- pin to control the servo if you connect a pullup resistor between it and the +5V supply to the servo. You will need to invert the output in the M950 command.

2500ccm

Thanks for all replies.
I will do it like @dc42 dc42 said. Which one do you prefere?

2500ccm

Now i got time to take this task on my todo list and installed a 3.9kohm resistor between 5v supply and signal. The 5v supply is external. I connected ground and 5v at external supply and signal at fan1-.
Commands are:
M950 S1 C"!fan1"
M280 P1 S125

Nothing happend. After that i googled and found in the duet wiki a part about external pullup resistor. 10kohm is recommend.
Is this my failure?

Thanks for reply
Moritz

dc42

@2500ccm the value of the pullup resistor is not critical. Did you connect the ground of your external 5V PSU to Duet ground?

2500ccm

@dc42 Sorry for my late reply. After i connected ground it worked well! Thanks alot