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

Lithium ion battery charger for robotics

This is a universal charger of Lithium Ion batteries based on Atmega8 microcontroller. As you may know, LiIon batteries have many advantages comparing to regular NiMh or NiCd. Main of them are: high capacity by weigh and volume, no memory effect, fast charge and so on.   But these batteries require special charging algorithm. You cant plug to some voltage and expect them to charge. It needs non constant voltage and current during charging cycle. Charging generally follows these steps: Current control at the Max Charge Current is used until the battery voltage reaches the voltage threshold (normally 4.1 or 4.2 volts per series cell). The battery is about 70% charged at this point; The voltage is now controlled very accurately (this is very important) at the threshold voltage while the current drops off naturally. Once the current reaches the lower cutoff ( about 100 mA per parallel cell typically), charging is stopped after a top-off time delay. So this battery charger consists of control circuit based on atmega8, charge control circuitry and reference voltage circuit. AVR-GCC v3.2 project files… Continue reading

Interface HD44780 LCD to USB port

This nice LCD2USB device is an open source and open hardware project. The mani idea was to make cheap solution of LCD connection to various PC’s via USB port. The total cost of LCD2USB is up to 10 Euros, while applications can be run under various operation systems like Windows, Linux, MacOS. This may be a nice addition to your PC to display various system information or simply for showing MP3 song titles.   Information which is sent to LCD can be configured and transferred with various well known applications like lcd4linux, LCD Smartie (requires a seperate driver), and LCDProc. USB interface is software implementation on AVR Atmega8 microcontroller, so no expensive special micros are needed. Project is very well documented and constantly updated. Download the latest version here. Continue reading

Multipurpose tiny AVR microcontroller board

Raph has designed this board for NES/SNES controllers to USB, but it found place in many more projects due to its small size and easy to use. This board is only 27.5×17.7mm size and is equipped with Atmega8 microcontroller. Circuit is already adapted for Firmware-Only USB Driver from Objective development including 12MHz resonator. Also there are several I/O pins available for custom programming. Because board it self is double sided, there is a place for SMD voltage regulator. Check out following projects where tiny board was used: X2Wii: N64, SNES or NES Gamepad to Gamecube/Wii adapter USBTenki: USB-connected temperature, humidity and pressure sensors. Infra-red receiver for Kenwood keyboard Gamecube/Nintendo 64 controller to USB adapter Four NES and/or SNES controllers to USB adapter Atari style joystick/controller to USB adapter Board is available for download as GERBER files. Continue reading