July 2026 Updates

32 MHz Crystal Start-up

Added a oscilloscope capture of a 32 MHz crystal starting up.

ESLs

Added info on electronic shelf-edge labels (ESL) to the bistable displays page.

LED Matrix Displays

Added a page on LED matrix displays, covering how they work, multiplexed scanning, driver ICs such as the MAX7219 and HT16K33, addressable RGB matrices (e.g the WS2812B), and the HUB75 interface.

nRF52 Clock Peripheral

Added info on the nRF52 clock peripheral, including the various clock sources, tolerances and calibration.

nRF52 APPROTECT

Added info on the nRF52 APPROTECT security feature, including the improved APPROTECT in later silicon revisions, and how to disable it in firmware.

Depletion-mode MOSFET Current Source

Added a schematic of a depletion-mode MOSFET constant-current source to the discrete current sources page.

Current Source Resistor Calculator

Added a calculator for sizing the source resistor in a JFET or depletion-mode MOSFET constant-current source.

eMMC Memory

Added a page on eMMC memory, covering the interface, speed modes, partitions and how it compares to SD cards, raw NAND and UFS.

MIPI CSI Communication Protocol

Added info on the MIPI CSI communication protocol, including the different versions of the protocol, and the D-PHY and C-PHY physical layers for MIPI CSI-2.

Cameras and Lenses

Added info on cameras and lenses, including camera sensors, camera modules, lens types, and field of view calculations.

Raspberry Pi Cameras

Added a page on Raspberry Pi cameras, covering how to use the Raspberry Pi camera modules, the picamera2 Python library, and AI Hats for Raspberry Pi.

Potting and Encapsulation

Added a page on potting and encapsulation, covering the different types of potting compounds, conformal coating, and things to watch out for when potting electronics.