Software Engineer Quality Assurance

Jun Liu

**********@*****.*** 862-***-**** **** Gibbons St, Hayward, CA, 94541, Jun Liu-Linkedin Key

Qualification

Firmware develop experience in bootloader, principle of control, wireless technology and serial bus protocols including I2C, UART (RS485), SPI in the Internet of Things (IOT) area.

Hardware develop experience in board bring-up, schematic capture and kinds of lab equipment including oscilloscope, soldering tools, electric load, logic analyzer and multi-meter.

Skills: Embedded C/C++, Python, C#, Assembly, Linux Ubuntu, RIOT OS, GIT, Jira Infineon XMC 1300 (Cortex M0), Nordic nRF52 (Cortex M4), J-Link, Arduino ZigBee, BLE, Ethernet, CoAP, cJSON

Experience Firmware Developer

Xenio System – San Francisco, CA Aug, 2015 – Mar, 2017 Point and Dash Pro Product

Led the firmware development process (hardware modification, feature development, bug fixes, version controls) to launch the first two IoT products at Xenio.

Built the bootloader including firmware update function into the system and programmed the corresponding command-line interface in the PC side.

Realized a PID controller to control the power real time and limit the error less than 3% for an adjustable peak current feature.

Fulfilled a multi-input (RDM/DMX, I2C and 0-10V analog) LED control system with flicker free and 0.1% dimming level supported.

Improved the PC GUI software written in C# for proof of concept, Verification & Validation (V&V) activities and component reliability test.

Restructured the maintainability of the firmware code as well as provided improved efficiency to guarantee the state machine status switch latency is less than 10ms.

Advised the OEM team in China about firmware flash, thermal measurement and the functional test sequence for mass production.

Dash Lite and Bult Product

Succeeded in board bring-up by hardware debug (with oscilloscope, electronic loads, multimeter etc) schematic capture, component selection and soldering.

Established a watchdog mechanism for a multi-thread system running RIOT OS to recover from any unexpected halt behavior and record reboot reason.

Enhanced the efficiency of factory initial setting by formulating the relationship between the desired peak-current and LED forward voltage.

Integrated automated test scripts in Python for the quality assurance and debug. Firmware and Software Engineer

Senorld LLC – Harrison, NJ Dec, 2013 – July, 2015

Architected and developed working prototypes on Arduino including a calorie consumption calculation algorithms for a wearable device.

Researched on RSSI-based positioning algorithms with the ZigBee protocol and measured some basic parameters for the customized devices.

Implemented ID broadcasting and data transfer in the mesh topology between 10 devices by using XBee (S1 and S2) API.

Academic

Project

Control Method Based on Wi-Fi & GPRS Network

Graduation Project Jan, 2012 – July, 2012

Modified the driver of WWAN card and LED in Linux 2.6.31 embedded on S3C2440 ARM9.

Implemented a remote control method allowing an Android smartphone to control the LED by messages through GSM or gesture through peer-to-peer WLAN. Education

New Jersey Institute of Technology, Newark, NJ

M.E. in Computer Engineering Aug, 2012 – Dec, 2013 Shanghai University, Shanghai, China

B.E. in Electronic Engineering Aug, 2008 – June, 2012

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