How to hook up to a simple transistor?

I have a fastrack supreme 10 modem. I have hooked up the GPIO pins to a transistor(base). But both a low and high output turns on the transistor. Is there any way i can make the transistor turn on at a high level only?

That’s a basic electronics question - nothing specifically to do with the Fastrack.

You must look in the Fastrack User Guide to find the output characteristics of its GPIOs, and use them to design your transistor circuit accordingly.

If you have connected the transistor’s base directly to a GPIO, you have probably blown-up the transistor! :open_mouth:

Take a look at this site for some introductory transistor stuff: kpsec.freeuk.com/trancirc.htm

Oh cuz the voltages and currents dont seem to be stable. Seems like different voltages based on wheather the modem is plugged into the computer or not…

What voltages?
What currents?
In what way do they seem to be “not stable” - how did you measure them?

Again, how & where are you observing these voltages?

How are you “plugging” the modem “into” the computer?

I use a digital Multimeter to measure then…one end to the modem GPIO the other end to ground

Plugged into the computer via the serial cable…