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Example Projects

The following are a sample of the projects RAT have brought into existence over the last 15 years...

Brake Response Timer

A mostly analog circuit that measures the reaction times of truck air-brakes. Measures air pressure and the time taken for pressure to reach a set threshold after the service brake pedal is pressed or released.

Brake Response Data Logger

ISA board transducer board
Garage equipment that prints graphs of truck air-brake response times. Test data is stored on the unit so that it can be printed in future or downloaded to PC. Unit is based on a single board PC design running a unix-like operating system (Linux in fact) booting from compact flash drive.

To create the product, RAT designed a switching regulator power supply board, a transducer amplifier board and an ISA / PC104 card to interface with an A/D converter and a LCD character display module. RAT wrote user software, thermal printer graphics drivers and unix device drivers. RAT also manufactured the custom designed boards.

Gryphon software

RAT developed all the major components of the embedded software for Dearborn Group's Gryphon and General Motor's Super CAN Analysis Tool products. RAT was key in developing the 'gryphon' TCP/IP network protocol used by both projects and wrote the network servers as well as a unix kernel space time-critical message scheduler and a myriad of Linux device drivers supporting vehicle networking protocols such as:
  • CAN - ISO11898 / SAE J1939, ISO11992, GM single wire.
  • SAE J1850 - HBCC hardware for Ford, DLC and BLIC for GM and Chrysler
  • CCD
  • KWP 2000
  • Generic UART
  • Honda UART
and device drivers for general I/O hardware.

As well as writing several hundred thousand lines of C code, RAT also worked with the project's hardware developers to help them make key decisions about hardware design and worked testing and debugging hardware prototypes.

Reversing safety system control circuit

safety system SLA charger
Microcontroller based board that decides whether a system that automatically applies truck brakes when obstacles are too near to rear of trucks should be active or not. Decision is based on various parameters including wheel speeds that the software calculates from ABS sensor waveforms. Unit outputs states of various parameters and internal variables along a serial communications line for diagnostic purposes.

The second board shown is a transistor based Sealed Lead Acid back-up battery charger circuit which was also designed for the project. As per usual, everything from the microcontroller software to the etching and populating of the first boards (shown in the photographs) was done in house by RAT. RAT can use both CAD and/or traditional non-CAD PCB techniques depending on what is most economical for the client - unlike a lot of other design companies who may not be able to design boards without relying on tiny track sizes, multiple layer thru-hole plated boards and spaghetti style 'auto-routing' of tracks.

Trailer Test Unit

compact scrutineer closed photo compact scrutineer open photo
Microcontroller based circuit. Tests truck trailer lights, EBS and ABS circuits. RAT both designed the electronics and wrote microcontroller software as well as producing the first half dozen units before arranging and assisting production by sub-contractors. An option for remote control by radio was added later.

ISO 11992 Electronic Braking System network test circuit

11992 board
Analog circuit that provides a simple voltage check of EBS voltage levels. Tiny project but sells well. SAE J1939 version also produced. RAT produced about 20 boards initially before handing over production to a board house.

Internet security auditing software

Netcraft logo
RAT wrote various Internet network scanning programs used by Netcraft Ltd's security auditing service. RAT also wrote a library to implement TCP/IP at its lowest level used by Netcraft for both its security testing and its Internet metrics, for example to identify what operating system webservers are running by looking at tell-tale differences of how they implement TCP/IP.

RAT logo Robin Arnold Technologies Ltd.