Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Measuring distances with SRF04 sonic module

Measuring device is combined of mini application module with Atmega128 microcontroller and two SFR04 sonic modules. Measuring principle is very simple. Measure time between sonic transmission and echo reception and then divide it by sound speed in this environment. Timing is explained in this diagram. Calculated distance is displayed on LCD screen. Sonic distance meter can measure distances from 3cm up to 3 meters and can reflect form 3 cm obstacles at 2 meter distance. I would say quite good addition to some robotic platform. Source codes are written for AVR-GCC compiler and can be downloaded form site. Continue reading

Traffic warning system for Los Angeles freeways

Traffic warning system or so called TDDY(Traffic Data Display ) is a vehicle-mounted, receive-only traffic warning system designed by Dubravko Gacina. System may be used to minimize the risk of vehicle like like public buses, emergency response vehicles, cabs, delivery vehicles accidents. An ATmega128 microcontroller and a matrix of 512 bi-color LEDs organized as a map of the Los Angeles freeways comprise the system.     Collisions between emergency vehicles and other vehicles are common events. Many of these collisions occur at inter-sections. Public vehicles approaching at 90 degrees to the direction of travel of emergency vehicles are very difficult to see. Sensors mounted on the vehicle could alert emergency vehicle drivers of approaching cross traffic. In such a scenario, sensors sends information to some sort of dispatching center which process incoming data and, in return, sends data to interested parties in form of positional information to traffic warning devices mounted in vehicles. This design presents an early implementation of traffic warning device. Conventionally, it uses server software hosted on PC and pager which serves as client to display position… Continue reading