Fixes
Arduino Nano “avrdude: stk500_recv(): programmer is not responding”: the six causes, in the order to check them
When an Arduino Nano shows up as a COM port but every upload ends in ten lines of “not in sync” and “programmer is…
Guides
STM32 UART bootloader on Windows 11: “No response from the target”, the pins each chip listens on, and stm32flash
The STM32 factory bootloader waits for one byte, 0x7F with even parity, on specific USART pins. Why Flash Loader Demonstrator says "No response from the target", the pin table from AN2606 for F1, F0, F4, G0, G4, L0, L4, H7 and C0, which chips stm32flash 0.7 knows, and a hosted stm32flash build with SHA-256.
Drivers
CMSIS-DAP, DAPLink and WCH-LinkE on Windows 11: HID or WinUSB, the 8010/8012 modes, and which tool sees which probe
CMSIS-DAP v1 is a HID device, v2 is WinUSB, and a WCH-LinkE changes USB ID with its mode (1A86:8010 RISC-V, 1A86:8012 ARM). What Device Manager shows for each, which driver, if any, to install, which of OpenOCD, pyOCD, Keil, MounRiver and probe-rs sees each probe, the hosted OpenOCD build with SHA-256, and the five forum failures explained.
Programmers
EZP2023+ and EZP2019+ on Windows 11: which driver folder is actually signed, and the chips the database does not have
The EZP2023+ package ships two driver folders and only one is signed for Windows 10/11: the other reuses the EZP2019+ catalogs, which hash a file that is not there. Both official archives with SHA-256, the install steps, the 896 vs 890-chip databases decoded, and the five failures from the forums with what the files say about each.
Drivers
CH340 driver on macOS and Linux: what binds the chip on each system, the brltty conflict, and when you need nothing
Linux has the ch341 driver in the kernel since 2.6.24 and macOS binds the CH340 with Apple's own driver since 10.14. A table of what binds 1A86:7523 on each system, the three drivers inside WCH's V2.1 macOS package (mirrored, SHA-256), the Ubuntu 22.04 brltty bug that still steals the port, and the fix for each failure.
Drivers
ESP32 board USB driver hub: which chip is on your board (CP2102N, CH340, CH9102, FTDI, native) and the driver for each
25 ESP32 boards checked against their schematics: the USB bridge chip on each (CP2102N, CH340C, CH9102F, FT2232HL or native USB), its Hardware Id, what Device Manager calls it and which driver to install on Windows 11.
Drivers
MediaTek USB VCOM driver on Windows 11: the signed Microsoft Update package, and what each 0E8D port means
MediaTek USB VCOM 3.0.1504.0 is on the Microsoft Update Catalog, signed by Microsoft: which of the 3 packages works on Windows 11 (SHA-256 here), the name of each 0E8D port from the INF, and the mtkclient USB change of 12 Oct 2026.
Drivers
Qualcomm HS-USB QDLoader 9008 driver on Windows 11: the signed driver, EDL, and what each 05C6 port means
Qualcomm now publishes the QDLoader 9008 driver signed on GitHub (QUD 1.00.94.13, SHA-256 here). Device Manager name of every 05C6 port (9008, 900E, 9091, 901D, 90DB) from the INF files, how to force EDL, and which driver QFIL, qdl and edl expect.
Fixes
Unknown USB Device (Device Descriptor Request Failed): what each Windows message means, and how to find the VID/PID
Port Reset Failed, Set Address Failed, Device Descriptor Request Failed, Codes 10/28/43/45/52: which USB enumeration step failed, what it usually is, and the next step. USBDeview 3.10 hosted with SHA-256.
Drivers
USB VID/PID lookup for bench tools: 53 chips, programmers and probes, and the driver each one needs
Where to read a device's USB VID:PID on Windows, Linux and macOS, a lookup table of 53 bench devices (CH340, CP2102, FTDI, PL2303, ST-Link, J-Link, TL866II, Pico, ESP32-S3, Saleae, Hantek) with the driver each one needs, and six cases where the number says less than you think.