nsec-badge VS SmartSpin2k

All the source files are open and available on Northsec's Github: https://github.com/nsec/nsec-badge/tree/master/hw/2023/hardware

Step zero is to decide how is your board going to be assembled. Do you feel confident enough to solder and assemble everything yourself or would you defer some of that job to a manifacturer. If you go with a manufacturer, check how they get their parts supply, that will limit which parts you can select. For example, jlcpcb offers a manufacturing service for board assembly, but the parts have to come from lscs. Then the first step is selecting the parts required. This one is currently quite tedious because there's a big part shortage. The bigger costier chips first as everything else will fall around that. In this case, we're looking for the microcontroller and the codec chip, then the power supply chips. I'd choose the microcontroller first as it's an easy but laborious step. You want a chip that has at least all the peripherals you need and make sure that they're not conflicting: some peripherals might block another from being used in certain places. It's a bit of a puzzle to solve. In this specific case, we'd want at least some i2s peripheral and an sdio too, i2c or spi for the screen, with some left over pins and some decent amount of flash that can also be user configured. Next the codec which will require some interface compatible with the microcontroller. For the power supply, i copied the design from a board i already worked on i was board tested and known to work: the 2019 nsec badge

Edit: maybe this was it? https://github.com/doudar/SmartSpin2k I don't know what your enjoyment for DIY stuff is, but this is doable.

This can automate resistance adjustment - https://github.com/doudar/SmartSpin2k

It’s a device that goes on the knob of a spin bike and turns it into a smart trainer. The project is in its 4th year and 3rd hardware revision. We went from no pcb to a pcb that was a carrier board for dev kits to now a full custom pcb. It works great! https://github.com/doudar/SmartSpin2k

Schwinn IC4 is a good bike. I hear good things about the Echelon Connect Sport as well. Both can be turned into a smart trainer with a bit of DIY effort using a SmartSpin2K to control the resistance dial automatically. It's a fun little addon that improves the experience. Worked brilliantly for me since I've got a very small condo with no space to bring a bike upstairs and onto a trainer. The spin bike was way easier to dedicate the space to 100% of the time and my partner also gets to enjoy it

Check out https://github.com/doudar/SmartSpin2k and add automatic resistance to your spin bike. Everything you need to build your own, or a limited number of pre built kits are available!

If the recumbent has a knob-based resistance control like a spin bike, you can use a SmartSpin2K device: https://github.com/doudar/SmartSpin2k with power meter pedals. (There's also a retail competitor, IDK about patents and such, but I always favor the maker version.)