A small AHRS was wired to a Jetson over USB, but nobody wrote down which serial port. Here’s how I tracked it down by its protocol instead of its name, fell into the classic dialout permissions trap, and decoded its orientation stream into human-readable numbers.
A rigorous per-stage latency benchmark across H.264, H.265, and AV1 hardware codecs on NVIDIA Jetson Orin (JetPack 6), measuring encode, wire, and decode separately at FHD and HD resolutions. AV1 wins end-to-end at 104 ms FHD / 86 ms HD. H.264 is the worst choice despite being the oldest: its nvv4l2decoder holds ~4 frames in an internal DPB buffer, adding 130–170 ms of hidden latency. Wire latency is governed by parse-element lookahead, not byte volume. Clock sync achieves ±234 µs via chrony. Full pipeline source, CSVs, and reproduction steps included.
Two processes on a Jetson, one camera frame in NVMM (GPU memory), no copies. The kernel does the heavy lifting via dma-buf fds; SCM_RIGHTS carries the fd across the process boundary; NvBufSurfaceImport reconstructs the surface on the consumer side; a cache-line-padded ring of atomic ref-counts keeps fan-out coherent without locks. With benchmark numbers and a Godbolt-runnable demo of the SCM_RIGHTS pattern.
A sequel to the first STM32H750 tracker post. After the C++ port was proven in production, I spent a week of evenings cutting dead vendor code, splitting the algorithm out to host for unit tests, wiring the LCD SPI through DMA to let the CPU run the tracker in parallel with the blit, unlocking the camera’s real frame rate, chasing a subtle BB-drift bug back to a too-wide SAD search, and finally building an offline A/B harness that compares SAD, NCC, and MOSSE on four synthetic scenarios so the next tracker port is a data decision, not a vibes one.
A long, honest retrospective on turning a WeAct STM32H750 board, a cheap OV7725 IR camera, and an Xbox controller into a live template-matching tracker. Every dead end, every wrong assumption, every fix — and what I’d do differently next time.
A step-by-step guide to mounting SMB/CIFS network shares on Linux — from one-off access in a file manager to persistent fstab entries with systemd automount that connect only when needed and gracefully handle VPN disconnects.
A hands-on walkthrough of configuring multiple monitors on Linux — from identifying displays with xrandr, turning off the laptop screen, ignoring lid close, to making it all survive a reboot. Every command explained.