Arduinifit

Arduinifit is a firmware to control the iFit Proform Pro 5000 (and probably other) treadmills using the original motor drivers.

About the Treadmill

The iFit Proform Pro 5000 is made of 3 primary components:

• Motor hardware (elevation and speed)
• Motor driver (MC2100, one driver for incline and speed)
• Controller
• Buttons
• Tablet (Android 2.0)

The tablet is most likely to fail since it receives periodic updates and they want you to "upgrade" (is a second running machine really an upgrade though?) as frequently as possible. The controller board communicates with it over UART, but I haven't been able to decipher its inner protocols. Most of the buttons are wired to it in a matrix, so it will be hard to reuse them without the UART connection. It connects directly to the motor driver.

The motor driver

The motor driver is controlled and sends feedback over a few wires. On the motor driver, each wire is labelled with a letter:

Wire/ Driver Pin	Purpose	Explanation
(G) Black/White	Ground
(S) Purple	Incline Sense	Pulses each rotation of incline screw.
(U) Yellow	Incline Down	Turns on at ~5v if Up is gnd (0v)
(D) Orange	Incline Up	Turns on at ~5v if Down is gnd (0v)
(P) Blue	Speed	PWM 20hz (19.5hz to 20.5hz)
(T) Green	Tachometer	Not connected. Future use?
(9) Red	+12v	9v, 12v... close enough, I guess
(G) Black	Ground

It should be noted that Incline Sense doesn't use absolute positioning, so I can only guess that the original tablet kept track of the incline and saved it to memory for when it was turned off. The Arduino doesn't have memory, so this won't work for us. For now, just take note when it stops moving.

Incline up and down must be pulled low by default, and both must be connected or neither will work. Setting each Arduino pin to 0 at start will suffice.

Wiring diagram. Use the Arduino pins described in the comment in the code.

Setup

Parts

• Arduino
• Broken Treadmill with a compatible controller
• 5k potentiometer
• 2 keyboard switches
• Some wiring

Arduino Installation

Configurations are stored in config.h. There are comments explaining what each value does. You can implement of leave out certain features (such as a safety key) based on your preference.

1. Open arduinifit file in the Arduino IDE and upload it to your Arduino.

2. Wire Arduino controls as in the diagram, using the pins named in the code.

   • 5k potentiometer connected to gnd, Arduino analog in, and 5v
   • Buttons connected to ground and Arduino inputs

Identifying Motor Driver Pins

Not all motor controllers will be the same. To identify each pin:

1. Start by finding ground and 12v with a multimeter. Otherwise you'll fry something. Touch each other pin and note any outputting power. If any are outputting 3.3v-5v, you may have found the incline sense and/or speed tachometer, if connected.

2. Next, switch to the ohmmeter setting and touch each pin. Note any connections near 0 ohms (that aren't ground) as these are probably outputs pulled low. You may have found the incline sense and/or speed tachometer, if connected.

--- You should now know Incline Sense, Speed Tachometer, 12v, Gnd ---

3. Next, upload the code to the Arduino and turn up the speed at least halfway. This will start the 20hz PWM signal. Check with the multimeter. It should either fluctuate voltage or read a constant ~2.5-4 volts.

   • If it's 0v, turn up the potentiometer and check your connections.
   • If it's above 4.5v, turn the power down.

4. Connect Arduino ground to driver ground.

5. Touch the 20hz Arduino pin to each pin that hasn't been identified and hold it there at least 5 seconds or until something happens.

   • If the speed turns on, congratulations!
   • If the incline changes, note the direction
   • If none of the pins respond, check your connections and turn the speed up/down. Check that the potentiometer is connected to both ground and 5v on the Arduino.

--- You should now know treadmill Power/Speed ---

6. Apply 5v to the remaining connections one at a time to identify Incline Up and Down.

--- You should now know Incline Up and Down ---

Pinout and identifiers

Driver Pin/Wire	Identification
(G) Ground	You know how to find this. 0v, ~0 ohms.
(S) Incline Sense	Output. Either 3.3v or 0 ohms. Try voltage first!
(U) Incline Down	Input. 0v out, but not ~0 ohms. Apply 5v to turn on
(D) Incline Up	Input. 0v out, but not ~0 ohms, Apply 5v to turn on
(P) Speed	Input. 0v out, but not ~0 ohms. Apply PWM 20hz (19.5hz to 20.5hz) for 5 seconds to turn on.
(T) Tachometer	Output. Not connected/infinite Ohms or same as incline sense.
(9) +12v	12v.
(G) Ground

Contributing

If you want to contribute (not that this is super niche...) feel free to write up an issue and fork the code. If you want to try another treadmill, put in an issue with the treadmill model, a picture of the board if available (close up on the pins is useful), and the board serial number. You can update progress there and I'll put whatever changes are needed on this end to make it easier.

Here's the wokwi simulation I use for debugging, using LEDs instead of motors: https://wokwi.com/projects/393810925685210113

TODO

• Safety key support
• Display to show current speed and incline
• Serial control and status
• Incline angle? Explore this.
• Detect if walking stopped using an accelerometer
• High/low speed modes wth safety