This may seem like a strange project, but I just don't know where to look to get this done.
I am a trainer of cyclists, and our athletes use power meters on their bicycles to collect performance data such as speed, power output, cadence, and more. The data is sent from the bicycle's power meter (which is typically inside the rear wheel's hub) to a Garmin Edge device using ANT+ technology (see [url removed, login to view] if you don't know what ANT+ is), and the Garmin Edge device displays and records the data for the cyclist to see and use in real time. The Garmin Edge device is about the size of a smartphone.
While this system works well, it forces the cyclist to look down at his handlebar where the Garmin Edge device is mounted. I would like our athletes to be able to put a motivational DVD into their DVD player and watch my team of coaches on their home television while seeing their ANT+ data (including real-time power, speed, etc.) in the corner of their television screen while they ride on their trainer at home. Or, if they don't like motivational DVDs, perhaps they can put on a football game or some other TV show while they ride on the trainer, and still be able to see their ANT+ data overlaid on the corner of the TV screen.
I'm having a hard time envisioning how this can be done, but I'm thinking that perhaps it involves a Garmin USB ANT Stick (look for it on Google) and an app/widget on a Google TV device. The ANT Stick allows a computer to receive the ANT+ data. I'm thinking that a Google TV device might work because it has HDMI input and output, as well as a USB port. I'm picturing that I can plug the ANT Stick into the Google TV device's USB port, and a Google TV app will collect the data and show it on the screen with video being displayed behind it. Google TV devices are capable of displaying icons on top of live TV, but I've never seen an application that displays live data, so I really don't know if this is possible.
I would also consider doing this using Apple devices, but the Apple TV device doesn't have any HDMI inputs, so I can't imagine how it would work.
If you have any other ideas, I would like to hear them. Since I don't know exactly what's going to be involved, I'm starting this out as a Very Small Project, but I'm willing to spend more if necessary. Let me know if you have any questions.