6328’s Operator Console: 2024 Edition
In this post we’ll talk about the evolution of the 6328 operator console, what we have going into 2024, and the design decisions that went into it. We’ll also discuss how it’s built.
The Ancestors
Here’s a little history…
2017-2019: Huge but functional
6328’s very first operator console was a monster. It was just a bit under the maximum allowed length, built of solid wood, and had dual joysticks for the driver plus a large button board for the operator. It was so large that it had wheels on one end and a handle on the other, so a student could pull it around the event. Here it is with our operator at our very first event, Granite State 2017. If you look closely you can see a bit of the wheels at the bottom and the loop handle in front of the blue button board.
We laugh now about how massive this thing was, but it actually served well for our first few years. Even at this early stage, it incorporated the concept of “override switches”: a set of covered toggles that enabled alternative behavior in the event of certain kinds of faults. This first saved us at the 2017 District Championship when, after a barely-finished drivetrain repair that didn’t include getting wheel encoders reinstalled, we were able to switch to open-loop driving (and win the match!).
We later moved the Surface Pro 3 computer onto a tablet mount for better driver viewing. This left us with an awkward keyboardless arrangement a lot of the time, so we added a separate e-stop button. Around 2019 we shortened the whole thing by a foot or so, in part because it wouldn’t even fit crosswise in a passenger vehicle for transport. We keep it around for the rare occasion when we’re running the 2018 robot. Here’s the current (ca. 2019) form, with the (usually detached) keyboard dangling off the tablet:
2020: The one-event wonder
The next iteration was for the ill-fated 2020 season. We switched to a recently-donated Surface Book computer, the driver that year preferred an Xbox controller, and we tried out a fancy new operator board. This was another large, simple, unfinished wood design:
This setup got used at our one 2020 event, and never again.
2021 Offseasons: Juggling!
By the time we were back at 2021 offseason events, it was clear that the operator, too, preferred a familiar Xbox style controller to a button board, so we carried around the bare minimum: a laptop & controllers. At that point we discovered that this minimalist approach had several serious drawbacks:
- With no button panel, our “override switches” became awkward on-controller button combinations. Instead of reaching down to a well-marked switch and flipping it, the driver or operator had to remember whatever button combination was mapped to the specific override needed. This also limited how many overrides were practical.
- Carrying a laptop, power supply, Ethernet cable/adapter, and loose controllers was a bad idea; things got dropped way too often, creating a real risk of something getting broken at the worst possible moment.
The Core Design (2022-23)
For the 2022 season we identified a set of basic requirements:
- Small and light enough to be easily carried (with comfortable handles) by our technician
- Wells to securely hold the driver’s and operator’s controllers
- Laptop secured in place but removable to pack for travel
- A built in power cord long enough to connect to power on either side of the driver station, or to use in the shop without always needing an extension cord
- All supporting peripherals (laptop power, USB hub, spare cables/adapters) securely mounted and out of the way during normal use
- When packed to travel, there should be no dangling wires, loose or other easily damaged parts. Since the laptop, controllers, and USB cables would go into our existing Pelican-style case, this mostly meant the power cord either needed to detach or tuck inside.
- A small number of physical override switches, ideally a group each for driver and operator
- We like “covered toggle” aka “fighter pilot” style switches as it makes it obvious which position is default - this reduces the chance of leaving something in the wrong position at the start of a match!
- Since this was 2022, we also wanted a physical toggle to control the Limelight LED’s (off/on/auto). In 2023 we repurposed this switch for other things, so even in the post-retroreflective era it’s proving useful.
The value of override switches
- Override switches provide the ability to override “normal” behavior to deal with faults or to help when working on the robot. They have saved us in many matches over the years. Here’s a couple of recent examples:
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While setting up for a 2022 Worlds qualification match, our alert system warned (after the gates were already closed on the field) that the ball-color sensor had become disconnected. This could have been a disaster, but instead the technician flipped the “Color Sensor Disable” switch, telling the software not to attempt color-based ball rejection. The drive team was cautioned to be a little more careful not to pick up the wrong color, but the robot otherwise worked fine.
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On the 2023 robot, we had several overrides relating to the arm. For example, one put it in “coast mode” to allow it to be manually manipulated. A separate “arm disable” could either disable it in the event of a failure, or if the code detected a problem and “E-stopped” the arm, toggling this switch served as a reset to try again.
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That list gave rise to this design, which we used in 2022 and 2023:
This is built of wood (¾” pine frame, ¼” plywood bottom and panels). We used an inexpensive commercial arcade controller to read the override switches and the toggle. The laptop is held on with dual-lock to a magnetically attached panel, with all the supporting gear tucked underneath. The wires to the laptop are easily routed through the grab-holes on either side of the laptop.
The 8’ power cord coils up neatly into the space under the laptop for transport. This unit, not including the computer and controllers, weighs under 10 pounds, so even fully loaded it’s easy to carry around.
We’ve been pretty happy with this design overall, and hadn’t planned on making changes…
Evolution for 2024: Are we seeing double?
Let’s start with where we ended up:
Yes, that’s two new operator consoles ready for service. (Well, one needs a laptop added!) This design is (obviously) an evolution of the 2022 one, with a series of small ease-of-use and robustness improvements.
At our 2023 off-seasons, we decided we should have a second proper operator console available, because
- When we bring a second robot to an offseason, as we did a few times this year, the second drive team is again left juggling (and dropping) a pile of stuff, and
- When we do drive practice with two robots, we’d like both drive teams to have the same setup.
A New Year, A New Size
The existing console was 36” long, which hasn’t been an issue with the technician carrying it around. But we decided if we ever build a robot cart that includes a place for the operator console, it would be nice to have it fit through a 32” door. To get it down to 31” without loss of functionality, we started by reducing the operator-side well and override panel from 8” to 6.5” and moving the 5 operator override switches a little closer together. (The driver side well remains at 8” as we’ve been experimenting with some alternative controls that are meant to drop into that.) We also took several unnecessary inches out of the computer panel. Finally, slightly thinner material in the frame saves the last fraction of an inch.
Overlays
Every robot maps different functions to the overrides, and many of our robots stay around for demos and development. The old model just had labels for the current robot, leaving everyone trying to remember what the switches did on last year’s. Since the size change meant we were doing a little more redesign, we decided to incorporate “overlays” that can be easily swapped, so we have the right labels for previous seasons’ robots. A 1⁄8’’ polycarbonate overlay, easily cut on the CNC router, fits around the switches. These align with the outside edges and are held in place with a single 10-32 thumbscrew, so they’re quick to change but won’t fall off. Labels for a given robot go on a set of overlays and we can keep around that set for as long as we maintain that robot. There’s enough space that we could even put maps of the controller buttons on them, if we wished (we haven’t done this yet though).
Of course, we wanted the overlays to work on either operator console. That plus the realization that refinishing the original was going to require stripping it completely caused us to decide we’d just make two new ones. We bought one new set of parts, and moved the other components from the original.
Race To The Finish
The surfaces of the operator console take a lot of wear and tear, and in just two seasons ours was looking pretty scraped and grungy.
For the top and inside surfaces, we switched from latex paint to multiple coats of a hard-drying enamel, using a random-orbit sander to level it between coats. Since the paint we used was only available in a gloss finish - not a good look - it has a final layer of a sprayed satin finish that reduces the shine:
With some coats taking two days to dry, the painting is the most time consuming part of the build!
For the outsides, we applied Tolex - a fabric backed, textured vinyl material often seen on the outside of guitar amplifiers. It’s available in a variety of colors, including our favorite - blue! It does take some time and care to apply, but we’re optimistic that it will hold up.
To cover and protect the exposed edges of the Tolex, we found these aluminum trims that are sold for tile. They have VHB-like strips on them, but we drilled holes and added # 4 screws. Narrow corner protectors work well for the top corners, again drilled out for # 4 screws, and traditional case corners go on the bottom (which takes by far the most bumps). This gives a nice, slightly industrial finished look:
Other Details
The technician is going to be carrying this around a lot, so comfortable handles are important. The ones we used are sold as kayak handles but work perfectly in this application. They can flip up on top if going through narrow doorways.
There’s a single arcade controller under the right-hand switch group, with multi conductor wire running over to the driver side switches. This board enumerates as a “Generic USB Controller” and has worked flawlessly.
The driver and operator controllers each get their own panel-mount USB connector inside their respective wells. This makes it easy to plug/unplug. On the driver side we went to a dual-USB connector “just in case”, since we had a spare port on the 4-port hub anyway.
Despite being smaller, the new units weigh a bit more, at around 11lb (without laptop and controllers). The Tolex covering accounts for most of this.
We’ve assembled a parts list with all the off the shelf components. There aren’t really any expensive parts needed; the investment in time to build a custom unit like this is the largest cost involved.
Let us know if there’s some detail you’re curious about that we didn’t address.
We’re looking forward to kickoff and a great 2024 season!
