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Firmware Flashing System

Firmware Flashing System

2
posts
2026

Ignition is a Temporal-powered system for flashing firmware onto devices at scale. It manages distributed workflows for individual device flashing, handles device re-enumeration and retries, and provides detailed state tracking for each device. The system was used to flash 2,300 conference badges, demonstrating its ability to manage large-scale, time-sensitive hardware operations. This post details the development of a custom hardware badge for the Replay conference, including its hardware components (ESP32-S3, OLED, IR, joystick, buttons, haptic feedback, LED matrix, gyroscope), firmware development in C and MicroPython, and the use of generative AI (Claude, Codex) to assist in writing the firmware and tests. The project involved significant manufacturing coordination in Shenzhen and was inspired by DEF CON badges and Pimoroni's Badgeware.

2026

Ignition: Flashing 2,300 conference badges with Temporal

8/4/2026

This post details the design and implementation of Ignition, a Temporal-powered firmware flashing system. It describes the use of Temporal Workflows to manage the flashing of 2,300 conference badges, including parent workflows for carriers and child workflows for individual badges. Key technical aspects include handling USB re-enumeration, implementing retry policies for flashing and validation, separating concerns between Workflows and Activities, and managing local Temporal deployments for distributed flashing stations. The post also highlights the importance of defining clear workflow boundaries and state machines for physical devices.

I built 2,000 badges for Replay and I’m not sure I’ve slept since December

5/20/2026

This post details the development of a custom hardware badge for the Replay conference, including its hardware components (ESP32-S3, OLED, IR, joystick, buttons, haptic feedback, LED matrix, gyroscope), firmware development in C and MicroPython, and the use of generative AI (Claude, Codex) to assist in writing the firmware and tests. The project involved significant manufacturing coordination in Shenzhen and was inspired by DEF CON badges and Pimoroni's Badgeware.