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

Atmega128 multipurpose meter

Atmega128 is quite powerful microcontroller giving enough I/Os, memory and interfaces. Don Carveth some time ago constructed a megameter – a multipurpose device based on this microcontroller. Together with PC interface megameter has a nice bunch of features including: Two 0 – 10 VDC voltmeters; One 0 – 30 VDC Hi-Z autoranging voltmeter with x10 jumper to give 0 -300 VDC range; 0 – 3 Amps high side ammeter; 4 channel logic analyzer; Frequency generator – 50% duty cycle square wave, 0 – 5 VDC, uC clock with divider, 1 Hz to about 8 MHz; Waveform generator – sine, triangle, square wave, 1Hz to 20+ MHz; Frequency counter; +5 VDC supply – 200 mA available; -5 VDC supply – 300 mA available Board communicates via RS232 interface. If you will… Continue reading

Multimeter for power supply unit

This multimeter was build as an addition to power supply unit by Zbyszek.   This unit uses ATMEL Atmega8 microcontroller which reads voltage (0…30V with resolution of 10mV), current (0…99A with resolution 10mA) and displays information on LCD. All you need is to mount multimeter to PSU module according to this diagram. Do not connect to voltages more that 50V as this may be dangerous for adapter and you. Author uses this multimeter for charging of RC Li-Pol cells. For this purpose you need to flash desired firmware which displays capacity passed to load, this way you can see how much cells are charged. Continue reading