Vision Pro Spatial Computer • Supported the bringup of 5 different hardware development platforms that culminated in the creation of the Vision Pro Spacial Computer. These platforms included pre-silicon, mechanical, and final form-factor builds, each requiring tight collaboration with hardware and numerous software teams across Apple.• Supported the development of the sleep/wake feature for Vision Pro. Prototyped and requesting hardware changes to simplify the transition from sleep to wake for the two-SoC design. (M2 and R1 Apple Silicon)Additional Prototyping and Development• Single-handedly brought up firmware for a dual-SoC (nRF52840 and STM32L4) prototyping platform, using ZephyrOS. Brought up a custom BLE interface, including OTA DFU capabilities. Brought up drivers for IMU, haptics driver, LED, and ADC-based battery levels. Brought up communication and data channels between the two SoCs, along with time synchronization and an RPC.• Supported the bringup of three additional development and prototyping platforms leveraging STM32L4 and nRF52840 SoCs, using an Apple-internal RTOS. Brought up drivers for motor driver IC, encoder, ambient light sensor, and temperature sensor, among others. Supported the bringup of three additional development and prototyping platforms using STM32L4 and nRF52840 SoCs using an Apple-internal RTOS. Brought up drivers for motor driver IC, encoder, ambient light sensor, and temperature sensor, among others. Partnered closely with the EE team to debug issues and provide feedback into hardware design.

Core Meditation Trainer• Developed all firmware for the Core Meditation Trainer, based on Nordic’s nRF52832, an ARM Cortex-M4 based SoC with integrated Bluetooth Low Energy. Wrote drivers for all components in the system, including IMU, ECG, ambient light sensor, haptic engine, and LED controllers. • Ported FreeRTOS and wrote all system code from the ground up to be thread aware and highly efficient. • Developed a method to leverage MIDI over BLE in order to live demo haptic-feedback via PC based Digital Audio Workstation (DAW, such as Logic Pro or Ableton Live) along with audio meditation content. This enabled a much quicker iteration cycle for designing haptic experiences to prototyping them on real hardware.

RearVision wireless automotive backup camera system• Provided development support for the Camera Frame, a solar-powered dual-camera system running the ThreadX real-time OS on an Atmel SAMA5 Series, ARM Cortex-A5 based SoC. Proficient with JTAG and debugging with the GDB debugger. Proficient with an oscilloscope and with developing and debugging drivers for inter-chip protocols (I2C, SPI, USART). Led efforts to reduce system boot-time and video request to first-frame latency.• Led debugging efforts for a third-party custom USB camera module and worked with the vendor to understand and root-cause any open issues. Proficient with the Beagle USB 480 protocol analyzer.• Implemented an SoC system-clock scaling mechanism that reduced overall system power by 50% during periods of low CPU usage.

iPod Nano digital music player (4th, 5th, and 6th generation)• Provided debugging support for an ARM1176JZF-S based system-on-a-chip (SoC) running the RTXC real-time OS. Proficient with the ARM tool-chain and JTAG run-time debugging. Assisted with the debug-ging of power-state transitions, such as suspend-to-ram (S2R) and resume.• Optimized filesystem stack for efficiently accessing audio and video content from NAND-flash based mass storage. Performed real-world filesystem fragmentation analysis to understand the effects on flash translation layer (FTL) operations. Designed a new cluster allocation algorithm to achieve a minimum video recording throughput under worst-case fragmentation conditions.• Developed a driver for a touch-screen interface in the RTXC OS environment and integrated it into the applications layer. Wrote an interrupt-driven SPI and UART driver for efficient communication with and debugging of the touch-screen chipset.iPod Classic digital music player• Supported the development of the CE-ATA hard disk drive (HDD) interface driver. Worked with two HDD vendors to integrate and debug 1.8” drives, from initial samples to final production units. Devel- oped firmware work-arounds for silicon defects to solve real-world failures. Led validation efforts for next generation CE-ATA host IP and coordinated with IP vendors to correct silicon defects.• Led debugging efforts for three generations of 1.8” PATA HDDs. Coordinated with HDD vendors to reach root-cause on factory reliability test failures. Developed a new factory validation test to catch real-world HDD failures.Additional research and development• Ported the CE-ATA driver to additional development environments, including iPhone OS and bootloader.

Falcon III series of software-defined hand-held radios• Developed firmware for the QNX Neutrino real-time OS. Provided hardware abstraction layer (HAL) support for Motorola’s i.MX1 and i.MX21 32-bit ARM-based SoCs.• Developed USB 1.1 compliant mass storage and communication port device drivers. Analyzed and de-bugged host-device communications using a CATC USB protocol analyzer.