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

Interrupt driven time keeper using ATTtiny2313

What is a clock? It’s a time keeping entity that increments at a constant rate. Szymon Dyja demonstrated how to keep the time using built in counters of the ATTtiny2313. Szymon’s simple design uses a 16×2 LCD with backlight and has an accuracy of 1 second / 48 hours. The 16 bit counter of the AVR is set to overflow when a second had lapsed, how to do this? Since the project uses an 8MHz crystal the counter is incremented every 8MHz/1024 and thus since the counter is 16 bit it will overflow at ((2 ^ 16-1) – (8000000/1024)) = 57822.5 which corresponds to a second. When the 16 bit counters over flow an interrupt is asserted, this assertion signals that the specific time span had lapsed and that global time variable needs to be updated which will also trigger the LCD update routines. Entire project can be downloaded here. The next step would be to add a synchronizing function to the clock to correct any inconsistencies. Time through Ethernet? Continue reading

ATmega32 starter board with LCD

Everybody that are starting with microcontrollers need some starting point – I mean a development board where they can prototype various projects and figure out how things works in embedded world. Atmega32 should be enough for many tasks you chose as it is featured with 32KB flash, 2KB SRAM and 1KB EEPROM and even more handy interfaces. This DIY Atmega32 development board has a standard alphanumeric LCD, RS232 interface to connect to PC, four programmable buttons, two additional buttons to generate external interrupts and DS1307 RTC chip – for easy time counting without occupying microcontroller’s resources. The board comes with standard 7805 voltage regulator, so any DC voltage sources up to 12V can be attached. If you are interested in following features just grab this design. It has no SMD’s so there should be no problem for everybody to build. Continue reading