I’d wanted to get onto calibration this week, but have been bogged down with a couple of issues.. So instead, will concentrate on the things that have made some progress.
The test harness code has been migrated into a new project, which is handling the real-time training data and buttons for GC, and setting the trainer resistance accordingly (just in slope mode for now).
It’s not properly calibrated yet, but can at least follow a course file, which I do find quite exciting – I still get a buzz out of the resistance changing automatically!
I’ve pushed the initial embedded source code (released under an MIT license) to github https://github.com/dresco/BudgetTrainer.
It soon became clear that sweating over my laptop or dev board, trying to press buttons while training was going to end badly, so I needed a way to more easily enter lap markers and manually change gradient while on the bike.
A rummage through the drawer of “things that may come in useful one day” turned up a spare remote from an old fan heater, which was quickly hacked up to provide a wired remote for some up/down, lap, and stop buttons.
The original servo didn’t have the power to get a full range of motion of the resistance cable. This week a replacement arrived from China, and I’d have to say I’m impressed. For less than £10 delivered, this metal geared analog servo seems solid, quiet, and has plenty of power (rated at 12.2kg*cm).
This seemed like a good opportunity to improve on my original coupling between the resistance cable and the servo arm, so I’ve made up a better linkage using a scrap of nylon sheet and coat hanger wire, and also repositioned the cable adjuster for a straighter run to the servo arm.
Next post I really will try to get onto the calibration! ;)