[E1][R][T] Tracked RC vehicle mode

A project log for Tetent [gd0090]

A water resistant, 300WPM input peripheral for end-to-end workflows.

kelvinakelvinA 06/02/2024 at 20:240 Comments

You may be wondering why a peripheral input device such as a mouse or keyboard would need to have a remote control. It probably doesn't, yet might only add up to £20 to the BOM of each Tetent depending on how fancy a camera (if any) one wants to install, and it adds quite a bit of fun and excitement to an otherwise engineered-from-necessity project.

Minimum Viable Project vs Exciting Feature Ideas. From my point of view, it seems like just a small detour.

I've been imagining things ranging from potential promotional videos to  proposed features over the past day or so, such that unless it's infeasible to manufacture, my next Tetent Concept will be a set of Tetrinsics on a 12mm thick curve:

12mm is also the thickness of the outline of Teti. The goal will simply be to have the outside dimension be as thin as possible. At most, I want it to be 32mm thin, same as the tracked vehicle from the last log:

I've been part of that 2-in-1 Laptop club for years, remote controlled scene for even longer, and liked that one Eggman scene in The Sonic Movie where a single vehicle had multiple smaller ones in it.

This tangent is based on the following observations:

This could be like the "pro" priced, advanced incarnation of the Hot Wheels stealth rides that I owned more than a decade ago:

Packed with more features and even stealthier.

I looked into the widest-angle, autofocus cameras I could find on AliExpress and I found 2 options:

Everywhere except this listing says it's a 13MP camera not a 12MP one. The product spec says it's 13.13MP so it's not a rounding error either.

There's a 5MP OV5640 and a 13MP IMX258, with the latter also having a larger field of view. The latter also sounds to have an ultra-fast autofocusing method. The following 2 videos are with the feature off, then on:

Considering how expensive Tetent is already estimated to cost, and how time consuming it would be to even add the feature, I'd most likely just go with the IMX258 because of the aformentioned features and that "13MP 4K" sounds cooler on paper, I'm planning to use Tetent for years so the £30ish BOM difference is easier to swallow, and HDR is supported. One of the drawbacks is that the datasheet isn't easily available, unlike the 5MP camera. Another one is that it uses a MIPI-CSI interface, which is just one more reason to wait for the ESP32P4 over using the STM32U5G9 today.

The camera would be mounted on the 45-degree bend of the curve mainly so it fits in the first place, but also so that 50% of the feed isn't the (out-of-focus) floor. One of my ideas was to have an inverse "Centre Stage" feature from iPads, where moving the controller (or the head with Tetinerary) would smoothly pan around the frame, instead of trying to stuff the entire view into a 400x400 area. I'm planning to leverage the "proprietary 2.4GHz" feature of the nF52833 for sending camera data if BT is too slow.

Additionally, I've got to find space for (camera) mounting hardware so that things can be mounted to Tetent, but also so that Tetent can be mounted to things (e.g. a chair or desk):

I'm also wondering if the "angle of attack" feature that the bluetooth modules used in Tetoroidiv can be used to emulate a kind of Blur IRL game mode.

This feature-tree of ideas also adds even more incentive to make the design water resistant. Imagine this: an ad that switches between someone calmly using Tetent as intended in a window-lit library on a wooden desk and it driving in the rain and mud at night whilst glowing like a snake in and sounding like a line in

Speaking of glowing, I found some 300 led/m strip, but it's £25/m and doesn't come in a diffused option:

Whilst the 2.7mm COB visibly has gaps in light intensity, it looks good enough and is 1/5th the price per metre.