Automation:bit and a servo

hi it is possible that lockdown is frying my brain but i cannot work something out. I want to use the automation:bit with a motor and servo to build an oscillating fan. I can get the motor turning using the relay of the automation:bit and i can operate the servo without the automation:bit. but i cannot figure out how to combine the two.

both the motor and servo are powered from a battery pack with the servo data connected to analog 3 and then try to control it using the servo extension using pin0 (which i understand is mapped to pin3 on the automation bit).

when both are connected the motor turns as required and the servo occasionally judders but does not turn as expected.

has anyone any suggestions.

thanks in advance and stay safe


The pinout is here if that helps.
Have you got all the grounds on one common buss?

all the grounds (battery, motor and servo) are connected to a breadboard and then connected to the ground pin on the automation bit. I cannot use the standard microbit and pin as it is hidden by the automation bit.

Best guess is it’s the “buffered” output that’s messing things up.
Would this help?

I thought that might be an issue, i had a look at the pinbetween and it looks interesting. many thanks for your help