A few days ago we mentioned a newcomer to the rig that we had not named yet. This is it. Capstan is a small round screen inside a ring you turn and press. Put one by the door, one by the bed, one in the galley, and every reading and every switch in your rig is a few clicks away. Leave it alone and it is a clock.
You can try it right now. The Capstan page has a working dial you can turn and press in your browser. Wake it, find Climate, dial in a temperature, switch the awning light. It is the fastest way to understand what the rest of this post is describing.
A dial, not another screen to tap
Most of the controls in a modern rig are screens you tap. That works fine until your hands are wet from the sink, you have gloves on, the sun is on the glass, or your reading glasses are in the truck. A tap target on glass gives you nothing to feel, so you have to look, find the spot, and hope you hit it.
A dial is different. Every click of the ring is one step, and you feel each one under your fingers, so you count clicks instead of aiming for a spot. Wet fingers and gloves turn a ring just fine. Three moves do everything:
- Turn to move through the apps, your lights, or a setting.
- Press to open, switch on or off, or confirm.
- Press and hold to go back, from anywhere.
We switched the touchscreen off on purpose. A screen that reacts to touch will eventually react to a sleeve, a kid, or a dog's nose on the way past. On Capstan nothing happens unless somebody meant it. There is a short Getting Started guide built into the dial that teaches those three moves, and you can hide it once you have them.
One for every spot, each with its own job
This is the part we are most pleased with. You do not set up Capstan on its own small screen. You set it up in Overlook, the TrailCurrent app that runs on Headwaters, on your phone, tablet or laptop, where there is room to see what you are doing. There you choose, dial by dial, which of your devices show up on it and which alarms it watches.
So the dial by the entry door can watch the door and run the awning and porch lights. The one beside the bed can run the vent fan and the reading lights. The one in the galley can have the water pump and the fridge outlet. Every one of them still shows your battery, solar, water tanks, air quality and leveling, because you want those everywhere.
The personal things live on the dial itself, in short menus under Settings that you turn and press through: which clock face you like, a light or dark look, 12 or 24 hour time, Fahrenheit or Celsius, and inches or millimetres for leveling.
Oh, and it is a clock
Walk away and the dial settles back to a clock face after a timeout you choose, anywhere from fifteen seconds to never. Along with the time it tells you the inside temperature and what the heat is doing, and the classic face adds your battery and fresh water. You get the useful stuff without pressing anything.
What is on it
Press once from the clock and the apps come up, each with a one-line summary so you often do not need to open it at all.
- Devices. The lights and switches you gave this dial. Press to switch one on or off. The screen only changes once the light has actually switched, so what you see is what is really on.
- Energy. Battery charge and time remaining, then turn for solar coming in and what the rig is using.
- Water. Fresh, grey and black tanks at a glance.
- Air. Carbon dioxide, humidity and temperature from the air quality monitor, with a plain good, moderate or unhealthy verdict.
- Leveling. A bubble, plus how many inches to raise which side. Not degrees you have to work out yourself.
- Alerts. A door left open or a tripped sensor takes over the whole screen, with a red ring around the edge. Press to snooze it for however long you set.
- Climate. Turn the ring to set a temperature and it shows you which way the cabin is heading and roughly how long it will take. More on this one below.
If a sensor goes quiet, its number turns to two dashes rather than sitting there showing an old reading that looks live. A wrong number you trust is worse than no number.
A ring of light on the smaller two
The two smaller versions have a ring of coloured lights around the glass, and Capstan uses it to tell you things from across the room. The whole ring goes red for an alert. On Climate the left half glows blue and the right half red, so you turn toward the colour you want. It glows green while a light you are looking at is on, and shows green, yellow or red for the battery. The brightness is capped, so it glows rather than glares.
Setting one up at camp
You will not need an app store or a signal. The first time a dial powers up, it creates its own little WiFi network and shows the name and password on screen. Join it from your phone, type in your rig's WiFi and the details for Headwaters, and the dial restarts already connected. Nothing leaves the rig and nothing needs the internet, so you can do it at a campsite with no bars at all.
Then open Overlook, give the new dial its devices and alarms, and it picks them up on its own.
Three sizes, off the shelf
Capstan runs on small round displays you can get straight from the people who make them. There is no custom circuit board to have made and no soldering for the dial itself.
- 2.1 inch, the Makerfabs MaTouch Rotary. The biggest screen. You press the ring itself. No light ring.
- 1.46 inch, the Elecrow CrowPanel Rotary. The whole screen is the button. Eight lights in its ring.
- 1.28 inch, the Elecrow CrowPanel Rotary. The smallest, for tight spots. Five lights in its ring.
The two Elecrow links carry our affiliate tag. It costs you nothing extra and sends a small cut back to the project. If you would rather it did not, search for the board on Elecrow's site directly. We would still rather you had the information.
For now you put the software on the dial from your computer, using the instructions in the Capstan repository. One step matters more than the rest: save a copy of the software the board shipped with before you replace it, because the makers do not publish a copy you can go back to. The instructions show you how.
The dial needs no soldering, but the rest of a TrailCurrent system does need some wire-to-wire soldering, so plan for that when you get to your next module.
Being straight about what is not done
The Climate screen is designed, built and on the dial, and the inside temperature on it is live. What it does not do yet is change your heat or air conditioning, because the TrailCurrent thermostat control it will talk to does not exist yet. We would rather ship the screen and say so than hold the whole dial back for it. Everything else on the dial works today with modules that exist now.
A mount for the 2.1 inch version is still being designed. The two Elecrow dials come in their own finished housing.
Why a dial, and why give it away
TrailCurrent has three goals. Build a real open source Software Defined Vehicle platform. Give it away. Teach other makers how to do the same thing with their own ideas. Capstan is the first two, and the dial on the product page is a little of the third: every screen you turn through there was drawn by the dial's own software, not mocked up for the website.
The screens were laid out in EEZ Studio, the same free drawing board behind every TrailCurrent screen, and the same colours and icons as Milepost on the wall, so two of them side by side match exactly. The software, the screen designs and the documentation are MIT licensed, same as everything else we make.
Go turn the dial, then have a look at the repository. More of the build goes up on the open source channel.