Hi,
i read the input signal between pin1 & pin3 by scope ..as shown below
How did you measure it, attached to the chair-controller or what?
Your measurements does not ring well with the manual, as the pins you measured should be the power supply.
What 'scope did you use?
i wanna control this wheelchair by microcontroller 8051 or another one ..no prblem
how to do that ..with regards
According to the manual that you supplied, the stick outputs a voltage proportional to the stick position, with half the supply voltage being center position. This could be emulated in a controller using PWM and a Low-Pass filter - I have no idea if the chair controller needs the differential signal that the stick is capable of though, but it shouldn't bee too hard to output both if needed.
If you need better/finer control, you need to add a D/A-C.
The manual for the controller may tell some more.
You need to resolve why the supply is pulsing on/off at 100Hz. It might be a way to reduce power, but since it would only half the power used, I'm doubtful about it - 'scoping it with the stick connected to the controller may tell you more.
Don't run this with a person sitting in it, unless you know exactly what you do (which it doesn't sound quite like

)