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Dollars, a feed, and who makes the board

Chris read the new front page and asked three things. Some prices looked like pounds. Could the devlog have an RSS feed? And are we building on the OpenMower board, or designing our own?

Prices in dollars

They were euros, not pounds: the RTK receiver, the used YardForce mower and the OpenMower kit are priced by European sellers. The site now shows everything in US dollars, rounded, at an approximate $1.12 per € (the November 2026 rate), and says so beside each table. The parts list in the repo keeps the seller's own price and adds the dollar figure next to it, because that's the number you'll actually pay at checkout.

Converting moved two estimates. The first real-robot goal is now ≈ $600–700, and the sensor stage is ≈ $500–700. The total for goals 2–5 is unchanged at ≈ $2,200–2,500.

An RSS feed

The devlog now has a feed: feed_rss_created.xml. It's linked from the front page, the site footer, and the RSS icon at the bottom of every devlog page, and feed readers will find it on their own. The dates come from each post rather than from git, because the blog is built in a container that doesn't have the repo's history.

The board: buy one first, then make our own

The board sits between the Pi and the mower: it drives the three motors, reads the lift, tilt and stop sensors, charges the battery, and holds the hardware blade interlock. Our software talks to it through one ROS 2 node, so whichever board we use, nothing above that node changes.

OpenMower has two hardware generations:

  • v1 is a single board. A web shop sells it complete for about $340.
  • v2, the current one, is a carrier board for each mower model with two plug-in modules: the microcontroller and the motor controllers. The project's own seller sells the kit, through the OpenMower community.

Either is a good place to start. We'd take v1 from the shop if two things hold:

  • It's in stock.
  • It isn't a dead end. It isn't: the OpenMower project still maintains it (its September 2026 release fixed a v1 board setting). For us it matters even less, because our software talks to the board through our own node. Moving to v2 or to our own board later changes that node and nothing else.

One thing to check before buying: that the kit fits the revision of the used mower we find. If v1 is out of stock or doesn't fit, we buy v2.

Then comes the longer-term plan: design and build our own board. The kit on the bench teaches us the mower's wiring and its real motors, and gives our driver node a known-good board to test against. Then we design ours next to it:

  • The reference: OpenMower publishes its YardForce carrier under CC BY 4.0, so its schematic is the reference for everything the mower plugs into. We can reuse it with credit, even in a board we might one day sell.
  • What ours adds: the hardware blade interlock and a separate safety microcontroller.
  • Parts: ones anyone can buy.

The full comparison, with licences, is in hardware/controller-options.md in the code repo. None of this is urgent: the next hardware stage is a push-cart with no motors at all.