Arduino controlled Treadmill, need advice.

Well, i am looking to control speed/elevation of my treadmill via arduino, i picked up a Sparkfun electronic starter kit (was like 90$) came with a Arduino uno (i think?) a year or two ago. Anywho, wondering if it would be possible to use relays just to control the buttons on the treadmill?

I think i would need relays and to solder wires on to both contacts of each button. i would like to maintain normal control, just want to add another. Would this be possible? I found a coffeeduinop machine tutorial that is similar to what i want to do but its too vague on a few things. i need a beginners guide, anyone point me towards a similar project or something? (i can’t remember any of the coding stuffs so i gotta start from scratch)

That might be possible, but you will run (pun intended) into trouble when you want to be able to use the buttons at the same time. Suppose the Arduino is doing a certain sequence to activate the buttons. If someone presses a button at the same time, the sequence would do all kind of wrong things.

It is possible to use relays, or reed-relays, or even optocouplers, or transistors, or direct wires to a keyboard to control a device. Some use that to be able to replace an existing keyboard on some very old equipment.

you will need to find where the buttons connect.

most treadmills have a main board that is all low voltage with membrane or tact switches.

if you look at the lower boards (typically two) in the base, you will often find a power supply board and a separate motor driver. the driver is often located completely separately.

the user pushes a tact switch, the logic board sends the signal to the power board, the power board opens or closes the relay that powers the up/down motor.

the user often slides a linear potentiometer that sends a signal to the driver board, that alters the speed of the motor.

if you have a simple, manual treadmill, it has a up/down relay and a motor driver.
no reason you cannot add your own signal to the up/down relay, however, you need to interrupt the existing signal so that you are not sending up while it is sending down. that would create a dead short and blow something up.

consider one relay that interrupts the manual values,
then the arduino takes over.

break before make.

or, you could add a switch and just disable the manual and let it run automatic until you flip the switch.

You guys rock, i would of been on here sooner had i not exploded a disk in my back trying to catch the treadmill from falling. (it slid off the back of the truck when i was lowering one end). anywho, when i can move again i will start updating this thread with my progress.