Embedded systems and devices

 

I specialize in the full-lifecycle development of firmware and applications across 8, 16, and 32-bit architectures. I have a proven track record of taking complex projects from initial architectural design to final release, with a particular expertise in developing robust communication stacks and high-integrity safety-critical systems.
 
 

2019 - Present
I joined SELLA Controls as a Contract Software Engineer to lead the implementation of the PPOS system for Transport for London (TfL). Following the successful delivery of the project, I was appointed Principal Software Engineer within the Mobile Solutions department. In this role, I lead a specialized team in the development of SIL-2 safety-critical systems for tram and heavy rail. My work focuses on high-integrity C++ engineering, ensuring strict adherence to BS EN 50128 and MISRA-C++ 2008 standards.
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Transport for Greater Manchester RESPOND (SIL-2 using C++ on embedded Linux)

I was responsible for designing and leading the implementation of a SIL-2 application that integrates a detailed map of the tram network with RF-ID beacon data to establish precise physical reference points. This allows the tram to calculate its real-world location and enforce over 750 distinct speed restrictions.
The software also incorporates a Driver Vigilance Monitor that tracks operator inputs to ensure active control of the tram.
In an event of a violation (overspeed or driver inactivity), the system initiates escalating responses: audible warning alarms are triggered, and if unacknowledged, the emergency brake is automatically applied to ensure a controlled and safe stop. All operational and enforcement data is simultaneously relayed to the control room via a cellular connection.

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Siemens Class 350 1/3/4 SODA (SIL-2 using C++ on embedded Linux)

An ASDO and CSDE SIL-2 application combining WTB (Wired Train Bus) and communication with a Tracklink®-III beacon reader.

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Alstom Class 378 AIRES (SIL-2 using C++ on embedded Linux)

Designed and developed an Automatic Power Change Over (APCO) system, certified to SIL-2. This project managed the train's power source selection (either the overhead pantograph or the third rail) by communicating with a pair of Tracklink®-III readers to process relevant trackside information.

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Tyne & Wear Metro TIGER (SIL-0 using C++ on embedded Linux)

Designed and developed a SIL-0 control system for critical communication. The application reads wayside beacon data via redundant Tracklink®-III readers and transmits this information using the TCMS protocol over Ethernet. Its core function is to automatically switch the tram's active radio frequency between TETRA and GSM-R based on pre-configured geo-fenced network boundaries.

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Citylink \ Transport for Wales \ Stadler CACTUS (SIL-2 using C++ on embedded Linux)

An ASDO and CSDE SIL-2 application combining CANbus and communication with a Tracklink®-III beacon reader.

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FLIRT \ Transport for Wales \ Stadler FACTS (SIL-2 using C++ on embedded Linux)

An ASDO and CSDE SIL-2 application combining ethernet, CANbus and communication with Tracklink®-III RF-Id beacon readers.

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Transport for London PPOS (SIL-2 using C on embedded Linux)

The Physical Prevention of Over Speed (PPOS) system is a SIL-2 rated solution built on the EKE Trainnet platform. Utilizing a Tracklink III Reader, the system detects beacons positioned throughout the Transport for London (TfL) tram network to identify high-risk zones.
The application software continuously monitors vehicle speed; if a tram exceeds the limit in a restricted area, the system interrupts power to the PPOS safety relay. This triggers a full service brake application, bringing the vehicle to a controlled standstill.

Incidents are reported in real-time to the London Tram control room via 3G/4G, with comprehensive data payloads transferred via the depot Wi-Fi network upon the vehicle's return.


2018 - 2019
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Floodline Hybrid Environmental Monitoring System (Qt C++ on embedded)

Developing a completely new standalone building management system. The main application is written in Qt and interfaces to a range of Modbus, BACnet and analog sensors. Each of the sensors (of which there could be hundreds) is polled every few seconds, its value logged and checked against user configurable boundaries, and raising audible, visual and relay alarms if out-of-bounds. Logged data and configuration items are stored in a PostgreSQL database allowing local and remote configuration of the unit.


2015 - 2017
Electricity Meter Platform Project (C++ on Thread-X embedded)

Implementing device driver classes for internal flash and external Quad-SPI flash RAM to be used by the bootstrap firmware upgrade process and for general storage. Both sets of drivers required a common interface to allow higher level code to operate without regard to the hardware physically attached.
Enhanced and cleaned-up Python code which parsed XML source files to generate C++ code which provides a common interface to variables and structures so that configuration data can be stored in external flash (thus reducing overall RAM usage) and which automatically saved and restored global variables across power cycles.
Implemented an external flash filing system, including wear levelling of flash sectors, to provide general and long-term storage for the system.
Adding AES encryption\decryption to the external flash access for data security.
Implementing new COSEM classes to provide electricity usage profiles, capturing and logging of events and diagnostic information.
Peer reviewed, MISRA-C++2008, C-STAT code running on RX65 and RX71 embedded.

SMR5 Phase 2 Gas Meter (C on RTOS embedded)

Building on my experiences with the two previous projects at L+G I worked as part of the team producing a down costed solution of the phase 1 meter.
SiLabs ARM-3 (Cortex-M). Peer reviewed, MISRA-2012, C-STAT and LINT clean code.

Italy Metrology (C on bare-metal embedded)

Optimizing to improve speed and reduce power usage of the existing code which measures the gas flow so the product could achieve its desired life span of 15 years of continuous operation running from a single battery.
Renesas RL78. Peer reviewed, MISRA-2004 and LINT clean code.

Additionally, providing user friendly PC tools to configure and monitor the gas meter whilst in operation.

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SMR5 Gas Meter (C on RTOS embedded)

I joined an existing team at Landis+Gyr initially to implement a device driver to allow the existing application code to interface with a new RF chipset (Analog Devices AD7023) and additionally to provide special builds to allow R&TTE (RED) compliance testing to be undertaken. Following on from this I moved to the main meter application code to implement new functionality within the industry standard M-Bus messaging framework.
Peer reviewed, LINT clean code running on embOS on a Texas Instruments MSP-430.


2013
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MOGA ACE POWER Controller
Working closely with the internal developers at Apple and under the tightest non-disclosure arrangements, Playvo developed the complete firmware for the first MFi approved iPhone game controller released to market. The final product used an Atmel UC3 processor scanning 14 analog controls at 60 Hz to communicate with the iPhone using Apples proprietary iAP2 protocol over a wired USB connection (Lightning connector), handled high definition audio over an I2S interface and controlled various sub-systems using I2C and TWI communications. Additionally the product allowed firmware upgrades over the USB cable, utilizing write-protected boot strap code which allowed for fail safe error recovery in the event of upgrade failure.

2012
An ongoing development and support contract working with a very well known US publisher\developer. Working closely with Diamond Apples own engineers, Playvo produced a C and Java SDK with full examples, FAQ and documentation to enable external developers to unitize the new standard interface for game controllers and haptics on the Android platform.

2011
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Dance Party (ARM-M7 Bare metal)
Working from the success of Motion-On-The-Move Playvo produced an ARM-7 based controller-less dancing game that mixed motion capture technology with streamed video producing a plug-in TV console with a sub $50 retail price. Screen shots and artwork here

2010

Motion-On-The-Move (ARM-M7 Bare metal)
A plug-in TV console aimed at the 2nd world market. The console integrated a 32-bit SunPlus GPL32 MCU, RF chipsets, 2 wireless controllers (with motion tracking hardware, G-sensors, and analog buttons) and SD slot. Motion-On-The-Move shipped with 10 built-in games which provided a mix of 3D and 2D games covering all the main genres, with additional games and level-packs being downloaded from the internet and stored on the SD card. In addition to providing input on the hardware specification and design, Playvo designed and developed a simple to use, but comprehensive API which allowed the Chinese software development team to quickly and efficiently produce the games for the unit. Playvo worked very closely with the Chinese programmers providing an on-site project management, technical support and training together with the tool sets required to complete the games. Additionally Playvo programmed the 3D games for the system. Screen shots and artwork here

2006
Working with the Chinese manufacturer Ever Sparkle Technologies to produce a range of unique optical products using a high end embedded processor.

2005
An ongoing project working closely with Ever Sparkle Technologies in China to produce a new and inexpensive console incorporating LCD and plug-in TV output options.
  Working with a high-end microprocessor to link together an iPod with several discrete components to provide a high quality video playing accessory.

2004
MobiCam
A project to create a device that used 1Mbit digital RF to transfer images from up to 4 separate remote cameras back to a portable display unit. Playvo where responsible for all programming on the SunPlus CPU together and interfacing the cameras, RF boards and LCD to the CPU.
An AGB accessory which allowed Hasbro's Colour Video Now CD movies to be played and displayed on the AGBs internal screen. Working with Hasbro's internal hardware engineers Playvo created an FPGA to enable the image bitstream to be decoded, enhanced and transferred through the cartridge port and be displayed on the AGB's screen. Playvo designed the image enhancement routines (implement in the FPGA) and programmed all the AGB user interface code which included passing back to the FPGA play, pause, etc. commands.

2003
WormCAM 2
Enhancements to the first version of the AGB-camera accessory, including better image compression to allow more images to be stored in memory, auto brightness and improved PC software.
Infra Red remote controller for PlayStation 2 which allowed any infra-red TV remote controller to control the CD and DVD functions of the PS2.

2002
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WormCAM
A digital colour camera for GameBoy Advance which saves pictures to non-volatile RAM in the camera module. Additionally WormCAM uses the AGB to provide picture editing, slide show, Spy-Camera and PC-Link functions. The project was engineered to interface through the AGB serial port to the camera and NVRAM. The mini-apps provided a paint program which allowed true colour editing of pictures, allowing users to draw lines, filled/unfilled rectangles, and enter text. All with multi-level undo/redo and then save the edited image back to the NVRAM. Spy-Camera uses motion detection algorithms to only save the picture when a significant change has occurred over the last picture. PC-Link is a Windows program linking WormCAM to a PC through the serial port. It provides thumbnail and full screen views of the pictures saved in the NVRAM; scaling and saving the pictures as .BMP files.

2000 - 2001
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WAVE Link \ WAVE Back
. A portable palm sized device aimed at the teenager market. Using 18 MHz Sharp 16-bit SM6010 processor and black and white LCD display. The device provides standard calendar, notepad, calculator, etc. applications together with email over a local network using RF communication. The email application also allows attachments created using the built in camera and audio sampling facilities to be transmitted wirelessly up to 500 ft. Playvo where responsible for implementing the complete operating system for the hardware writing low level drivers for: Flash RAM; camera; audio sampling/playback; filing system; graphics primitives; interface to the RF hardware; stylus reading; and downloadable game support. Additionally Playvo completed the Planner, Sketch Pad, Tape Deck, Auto Cam and Calculator applications.