rulos VS zephyr

(This was previously submitted as https://news.ycombinator.com/item?id=2246856)

The Ravenna Ultra-Low-Altitude Vehicle is a backyard rocketship treehouse nestled in the Seattle neighborhood of Ravenna. Click the link to see a demo video.

The hexagonal treehouse is about 6.5 feet (2 meters) across at its widest point. The frame is welded mild steel with riveted aluminum siding. It contains nearly 800 LEDs forming dozens of numeric displays spread across 14 control panels, each with an acrylic face laser-cut and etched with labels such as "Lunar Distance" and "Hydraulic Pressure". The pilot controls the rocket using a joystick and panels full of working switches, knobs and buttons. Underneath the capsule are three "thrusters" that shoot plumes of water and compressed air under the control of the pilot's joystick, simulating real positioning thrusters. Takeoff and docking sequences are augmented by a paint-shaker that simulates the vibration of a rocket engine. Sound effects complete the illusion, with a powered subwoofer that gives the rocket a satisfying rumble.

When it was built in 2011, rocket operations were controlled by three Atmega328 microprocessors on custom-fabricated printed circuit boards, running a small operating system, RULOS, built just for this project. A trench running from the house to the rocket carries 12VDC power for the lighting and electronics, water for the thrusters, compressed air, and several data signals.

Since 2011, the two-person team has upgraded it, here is a recent update from the makers:

One of the most visible changes is replacing the primary 4-line display with a slicker 6-line display (i.e., 6 rows of 8 columns of 7-segment LEDs). The audio synthesizer has been upgraded to a PCB that can generate 50khz, 16-bit audio. The interconnection bus, which had been flat IDC cable carrying individual on/off lines, was upgraded to a true I2C-based networked distributed system with over a dozen individually addressable targets, all interconnected by standard cat5 cable that carries both our I2C protocol and power. We also moved much of the electronics from 8-bit atmega328s to newer, 32-bit STM32F3's. RULOS has been expanded into a pretty general purpose embedded systems platform ported to 5 major lines of CPU (atmega, attiny, stm32, nxp lpc, and esp32). We've used it for dozens of other projects in the last 12 years, including a nanosecond-accurate timestamper, a GPS datalogger, an air quality sensor, various little electronic control boards for toys (e.g. these, and this), and an autonomous boat (that sank). It is all available on [github](https://github.com/jelson/rulos).

Master Control Board, based on stm32f303. This is different than the others because it feeds 12 power into the RJ45 connector. It also regulates input power down to 10v for the bus driver.

Hey folks. Anyone out there waiting for BT Auracast? It was announced June 2022, and immediately struck me as must have.

I lost my earbuds, but it seems ridiculous to get a replacement without Auracast, seems like surely if I'm going to make a decent sized purchase like that it needs to support group playing. I want to tune into the radios of other people on the metro or on the bus, want to be able to watch a movie on the plane with someone.

Auracast was announced in June 2022. Anyone else out there struggling with expectations here? I'm really hoping the product announcement season that's right around the corner had a good number of Auracast announcements.

Side note, a ton of it is over my head but it's been so so fun tuning in every once and again to see how Zephyr's Bluetooth Audio work is going. Just wild now much has gone into this! https://github.com/zephyrproject-rtos/zephyr/commits/main/subsys/bluetooth/audio

I am working on adding support for VisionFive 2 in Zephyr RTOS. I have created a device tree by referencing the starfive linux, patches of hifive_unmatched FU740 SoC and patches of BeagleV Starlight.

We are unsure on how to proceed further with this error. We have opened a github discussion regarding the same issue.

Then there are samples. Look through it for anything useful. RC522 uses SPI, so getting that to work would be a good first step.

Hey, I've been trying to build an app with cmake+ninja instead of west to integrate it into a larger build system and everything works correctly except for the final stage where it uses `/usr/bin/llvm-objcopy` instead of the `${CROSS_COMPILE}` one it tries to find here.

Zephyr has a lot of good points, but I really wish it didn't use Kconfig. Getting a working config seems to be mostly a matter of copying an already working example. It might be okay for hardware side of things, but it's a really bad at software/feature dependency.

Set https://docs.zephyrproject.org/latest/build/kconfig/tips.htm... and the issue: https://github.com/zephyrproject-rtos/zephyr/issues/52575. And don't even get me started on trying anything to group options together.

In this thread u/ikravets explained that there hasn't been much demand for Zephyr, which is why they aren't doing anything with it, and in this pull request Zephyr decided to no longer recommend PlatformIO in their documentation.

The answer is always in the source: https://github.com/zephyrproject-rtos/zephyr/blob/bdaac354f4cb0ad91d952c2f6941c16240d84da2/subsys/tracing/tracing_backend_ram.c