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

PIC PAL video OSD superimposer

This project really pushes 8-pin PIC microcontroller to its limits. It takes only a few elements and can do really cool things with your PAL TV screen. It simply adds various text effects to PAL composite video signal in real-time. The circuit is overclocked with 25MHz crystal and it works fine. Super imposer uses the same video signal to synchronize itself by detecting 28us low-level pulse in comparator input. After synchronization, super imposer sends text constructed from 5×7 elements stored in RAM memory. Only two colours can be imposed – black and white. Project files are here. You can also see working Super imposer Youtube. Continue reading

PC controlled dual stepper motor driver

This stepper motor driver can control two independent steppers via RS232 interface. Control commands can be sent by using simple terminal program like HyperTerminal. Circuit is capable to drive two unipolar stepper motors operating in full step mode. Motors can be powered from 24V and consume up to 0.5A of current. ATtiny2313 microcontroller sends control pulses via ULN2803A chip, which can drive up to 500mA. Firmware is developed by using BASCOM AVR software. Or you can just download hex file which is ready to flash to microcontroller. This might be useful device for testing stepper motors. Continue reading

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

AVR DTMF decoder based on MT8870DE

There are many versions of DTMF decoders outside the Internet, but all are doing pretty the same – decoding dual tone codes in to digits, that can be later interpreted by microcontroller. This device uses an integrated decoder chip MT8870DE which decodes all 16 DTMF tone pairs in to 4 bit code. AVR Microcontroller reads these codes and outputs them to LCD as characters. DTMF receiver stores last 234 received digits in EEPROM that can be viewed by scrolling an LCD character line. DTMF Decoder also can be connected to PC via RS232 interface. So each time TDMF signal is received it sends digit to Terminal. Program is written by using free WinAVR GCC compiler tools. Continue reading

Short range IR radar system

This is a short-range personal radar device that uses any standard sharp IR sensor along with a servo and PIC microcontroller for control. The overall budget may be less than $30 and can be built in a few hours. IR radar can sense obstacles in range of 4 to 5.5cm distance depending on IR proximity sensors used. It scans 90º wide areas. So it really can make parking easy – well radar scanner has to be protected somehow from rough environment. Well cars are not the only place where it can be used. Radar can be eyes of mobile robot. IR Radar is controlled by PIC18F452 microcontroller which controls servo motor scanner, reads IR proximity sensor and displays radar information on specially oriented LEDs. Cool project to experiment with. Continue reading