Yun/Uno differences Solid State Relay

Greetings, having fun with the Yun but have encountered a weird problem when driving a motor on fotek SSR's

http://www.fotek.com.hk/solid/SSR-1.htm

When I set the pin high the SSR fires but the motor jumps about like crazy, as if it is not getting a steady supply, now before you say inductive loads/snubber circuits etc, if i run the same code on the Uno it runs perfect

Any clues?

Cheers....

Could this be related to the differences between an Uno and a Leonardo? (the yun has the same MCU)

That's what I thought at first but the specs for both suggest you can sink 40ma from each io line...

Running PWM ?? wont work! Maybee 3.3V out is just not enough to keep relay steady activated. What about feeding the SSR 5V and use a LOW output to activate it. ouput HIGH or defined input should turn off

Nope no PWM, literally just configuring the pin as an ouput and setting high... driving me mad... get the same effect if i run the yun off my laptop on batteries so i think i have eliminated dirty power source...

se last edit..

i thought the yun was meant to output 5v on the IO lines?

From the description:

Each of the 20 digital i/o pins on the Yún can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms

Will grab the meter and check this afternoon....

Just checked and I'm getting 4.8volts out of the pin in question....

I understand this:
On Arduino UNO - this works OK (so do my projects with uno and same SSR)
4.8V when connected to SSR ? (and green light lit on the SSR)
This should absolutly keep the relay AV-side turned on.
…I’ve got no more ideas, since i don’t have a “yun” do to testing…
(last chance: try another (or two simultanios) pin(s))

Yeah the light on the SSR (red in this instance) remains rock solid throughout, but that does not seem to be a guarantee that the SSR fires, for example if I put a low value resistor on the output the LED still lights but the SSR does not switch... It feels like the yun does not quite have the same ability to provide current as the uno....

I think my next step has to be pulling the pin down rather than up...

Sorry just to reply fully, I have tried different pins with the same result will try doubling up..

..I cannot se another "last go" either.. - without modifying too much