Milepost is the touchscreen on the wall of your rig. Tap it to turn lights on, see what the battery and the solar are doing, check where you are. The new video puts the board behind the glass on the bench and walks through why this is the one we picked.
Why we switched boards
The first version of Milepost was built on a small touchscreen board hobbyists call the Cheap Yellow Display, or CYD. It is a fun board to play with on a desk. It is not a board you want to hang on the wall of an RV. To make it do everything Milepost needs to do, we were soldering header pins onto it to reach signals, taping a separate chip onto the back to give it a CAN bus connection, and taping a small power converter next to that to step the rig's 12 volts down to something the board could run on. It worked. It looked like a science experiment.
The new board is the same idea done properly. The 7-inch touchscreen and the brain are one piece. The CAN bus connection is already on the board. Power still needs to be stepped down from 12 volts to 5 volts, but the screen comes with the right cables in the box, so the converter just plugs in between two factory connectors. No soldering on the screen. No tape on the back. The rig harness lands on the board exactly the way it was meant to.
What turns up in the box
What Waveshare ships is a complete unit. A 7-inch screen with the touch sensor bonded to it. The brain in the middle with plenty of room to run the Milepost interface comfortably. WiFi and Bluetooth built in. A USB-C port for plugging into a laptop the first time you load the firmware on it. A CAN connector for plugging onto the rig's network. A microSD slot, a spare battery connector, and a few other small connectors that Milepost does not use but that are there if you build something else with the same board. About all you add are the cables, a small buck converter, and the 3D printed wall mount.
How it talks to the rest of the rig
Milepost sits on the rig's own internal network, the same wire the lights, the power distribution box, the GPS, the battery monitor, and the solar charger sit on. When the battery dips, the screen sees it. When you tap a light tile, the right module flips that light on. Nothing is going out to the cloud and back. Nothing is waiting on the internet. The screen reacts as fast as the wire next to it.
That is the real reason we picked this board over any other 7-inch ESP32 touchscreen. Most of them assume you live on WiFi. This one ships with the CAN connection already on it, which is exactly where Milepost needs to be.
How updates work
WiFi only wakes up when there is a new version of the firmware to install. The CAN bus tells the screen there is an update for it, the screen joins the WiFi network long enough to download and apply it, then WiFi goes back to sleep. That keeps the screen quick and predictable the rest of the time.
WiFi details get to the screen the same way. They come in over the CAN bus from another module on the rig. There is no card to image, no captive portal to log into, no QR code to scan. Whether you have one Milepost on the wall or three, the process is the same.
The wireless cousin
There is a sibling board in the same Waveshare lineup that runs Fireside, and we cover it in the Fireside video. The difference between the two is not really about the screen, it is about how each one is plugged in. Fireside is wireless. It talks to the rig over WiFi instead of a CAN wire, which means it has to do the extra work of WiFi networking on top of drawing the picture. To keep the wireless screen feeling just as quick as the wired one, we put it on a beefier Espressif chip. Milepost is wired straight onto the CAN bus and does not have to carry that extra load, so the cheaper, simpler chip in this board has all the room it needs. Same kind of job, two ways to mount it, and a noticeably lower cost for the wired build.
What it is not great at
Every board makes trade-offs. The ones worth knowing about before you order this one:
- The screen tops out at this resolution. 1024 by 600 is sharp and easy to read across a galley. If you need much higher resolution, you are on the bigger Fireside-class board, not this one.
- One of the USB ports is shared with the CAN connection. The board has two USB-C ports. The first one is the one you use to load firmware. The second one technically exists, but it shares wires with the CAN connector, so on Milepost we ignore it.
- You bring the wall mount. Waveshare ships the bare board with little metal standoffs and a clear acrylic bezel, and that is it. For Milepost we 3D print two parts: a flat plate that screws to the wall, and a screen housing that slides straight down onto the plate. A couple of screws lock the housing to the plate once it is seated so it stays put as the rig moves. Files are on the Milepost product page and on Makerworld.
- No speaker on board. If your project needs to make noise as well as show pictures, the audio is on you. Milepost is silent on purpose. Audible alerts come from other modules.
None of these are dealbreakers for a wall-mounted control panel. They are just the things worth knowing before the box turns up.
Getting one on your wall
The board comes direct from Waveshare at waveshare.com/esp32-s3-lcd-7b.htm. That link carries our affiliate tag, which costs you nothing and sends a small cut back to the project. If you would rather skip the tag, strip ?&aff_id=Trailcurrent off the URL.
Once it arrives, the rest is on this site. The Milepost product page has the wiring diagram, the printed parts, and the install steps. The TrailCurrent Flasher writes the firmware straight from your browser through the USB-C port, so you do not need to install any developer tools. After that first flash, every update arrives over the air on its own. The full source code, the user-interface project, and the network message reference live in TrailCurrentMilepost on GitHub.
The review is on @trailcurrentopensource, the second TrailCurrent channel. The main @trailcurrent channel covers what the system does and what it is like to live with on the road. The open-source channel is for the part underneath: hardware reviews, design decisions, the bench work. If that is what you came for, that is the channel to subscribe to.