Triathletes/Runners/DIY Geeks: Have you ever wanted treadmill speed/distance on your watch?

I did too… so I created an ANT+ treadmill “foot pod” for about $15 in parts. The entire journey is documented at

I’ve been using it for a few weeks now and have been overall impressed by it so I thought I’d write everything up and share it out there.


Only just realised what you were getting at with talk I was thinking it was going to be like Coach Chad’s comments on TR but with your treadmill shouting ‘Run Faster, Don’t give up’.

First post and I already failed at creating a title. :frowning:

Made the title a little more straight forward… now I better stop over-thinking it and get my workout done.

Please make one for the Waterrower S4 monitor. There is good business opportunity as there is no solution right now and thousands of Waterrowers on the market. With the Zwift Pod for $29.95 there is tough competition for running pod.

The S4 monitor has an API for speed and power but there is no solution to transmit data via Ant+ or Bluetooth to the watch or training software on the PC/smartphone/laptop…

I’ll take a look at the S4 API to see how something like I did could work.

Not really looking to sell anything here. This was mostly a DIY project because I didn’t like that my treadmill and watch were in so such disagreement and I wanted to learn some new skills.


It looks like the Waterrower S4 USB communications have been documented pretty well, so that side doesn’t look too complicated.

The Concept2 PM5 looks like it uses either FE or FE-C ANT+ profiles, but most of the Garmin watches don’t support those profiles. Newer bike computers would support FEC. There is ErgIQ, a Connect IQ app, that most likely implements the display side of FE/FE-C that would add it to the watch.

I think a Raspberry Pi, USB ANT Stick, and Micro-USB cable and some Python coding could make a small device that could take the data from the Waterrower and broadcast it out ANT+. You could probably even get rid of the ANT stick and go with a Raspberry Pi Zero W if only broadcasting out over Bluetooth. It looks like there is a Bluetooth spec for Rower Data.

I think this project might be just what you’re looking for. It’s going to require an android device:

Just throwing this out there…

Apple Watch captures treadmill workouts…

Thanks @Bplgocards, my wife has an Apple Watch so I’ll have to see how it compares to Garmin watches.

It likely uses an internal accelerometer much like the Garmin watches do and in my experience this method starts to depart from the reported distance on the treadmill when I run at different paces indoors.

The DIY “foot pod” I put together instruments the treadmill belt (by counting revolutions) to report its speed and distance traveled to the watch over the ANT+ stride-based speed and distance monitor (foot pod) profile.

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Not really, as I want a device that makes it a BLE power meter with cadence and speed info using standard BLE profiles.

This project has intended to do it:

It does not use standard BLE profiles. It works with Zwift when compiled but not with a Suunto watch. It does not transmit speed data as it is just using the power meter profile. It comes close to what I am looking for.

If you want to make it commercial project it should be a downloadable image for the raspberry that can easily connect to the internet. In the internet you would purchase „access“ (best after a free trial period).

Ah, I see what you mean. I looked through that project and back at the S4 USB API document and it looks like they just never pull speed or distance from the memory. It looks like those fields can be accessed with the IR command (their this.readMemoryAddress function). Although, it looks like others don’t necessarily trust the distance, but it could be worked around with the calculation they mention.

I tried to find out what Bluetooth sensor specifications Suunto watches support but couldn’t really tell. I’m also not that familiar with how Bluetooth sensors usually work, so maybe it all comes down to what the existing software supports. I also don’t know anything about rowing tech, so maybe this is already solved.

If I had the equipment lying around the house I’d definitely hack up those pieces missing from the project. I think it could be done in not too much time and it’d be a fun project. Unfortunately, my wife will definitely put the foot down to another watch or rowing machine entering this house.

That’s it I found!
I think you can use IR sensor to the motor or gear of treadmill not to belt.
Also, this device make treadmill smarter to use zwift run.