Marlin controlling a solenoid via heater E1

Hi,
I'd like to be able to control a 12V 300ma solenoid from my MKS BASE v1 board (http://reprap.org/wiki/MKS_BASE_1.0) which reports using Marlin V1 firmware RAMPS_13_EFB

From what I've researched it would appear that I should be able to use Gcode of M42 Sxx Pyy to set pin yy as output and then to value xx.
I downloaded the latest firmware source and read marlin_main.cpp where I see the M42 sets any pin supplied (Pyy) to output and then drives it to the Sxx value.
I tested this with scripts in repetier host and could toggle the LED (setting it to 255 and then 0 after a delay) and also make the LCD's buzzer work (P33). So far so good.

I can't find a schematic for the MKS BASE but it says it's RAMPS compatible so I was expecting [reprap.org] would also describe the MKS base.
D9 looks like the pin for this heater but using 8, 9 or 10 as the pin number in the M42 command didn't work. Am I using the wrong pin number or is there something else I've missed?
The fact that I can't control the E0 heater or the fan (D8 and D10) suggests I'm still missing something.

Any guru able to help me solve this?

Many thanks. ...Laurie:{)

Replace the pin you want to use with M42 in the pins.h with "-1" and M42 should also work on 8 9 or 10.

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Triffid Hunter's Calibration Guide

--> X <-- Drill for new Monitor

Most important Gcode.

Hi Wurstnase,
OK, that's not what I was expecting. I thought the -1 indicated the pin is not be available.
Glad I asked.
Was also hoping not to have to recompile, but, if that's what it takes then so be it.
I'll give it a go and let you know.

Many thanks again. ...Laurie:{)

All pins are available everytime. But some are assign to something in the pin.h.

---

Triffid Hunter's Calibration Guide

--> X <-- Drill for new Monitor

Most important Gcode.

Well thanks for the advise, but it turns out that the right pin to use is pin 7.
So, M42 S255 P7 turns on the E0 heater pin which I want to use to run the solenoid.
Indeed, it happily runs the solenoid from the test I just did.
M42 S0 P7 turns if off.

Thanks. ...Laurie:{)