Small portable PIC16F84A driven Nixie clock

Most of Nixie clock designs end up with at least four indicators that display time at once. More Nixie indicators require more space and power. But pinomelan decided that single digit IN-12 Nixie indicator is more than enough for building small portable digital clock. He put small PCB with PIC16F84A which drives single Nixie with discrete transistor. Nixie tube needs high voltage to light up, so he used HV supply from disposable camera. Clock displays time by periodically flashing all digits in series. During display each digit can be set up by pressing button at the right moment. Nixie clock along with battery could fit in to 35mm cube enclosure if needed. Continue reading

PIC16F628 based 8 running lights controller

You have probably already build several LED light effects. These are simple to build as only microcontroller, resistor and LED is needed. But probably you will agree that flashing powerful lamps is more exciting and so dangerous as well. Rajkumar Sharma posted his 8 channel running lights controller that can handle 100W light bulbs on each channel. Controller is based on PIC16F628 microcontroller which drives 8 opto-isolated triacs where each can handle 230V and 100W. Running lights effects can be changed with three tactile switches. If you planning on organizing party this might be a great next project. Continue reading

Cascade-able RGB light effects

This is a simple project which creates RGB light effects driven by microcontroller. It uses a custom built RGB LED strip that can be cascaded in to long lines. LEDs are controlled in groups where different color belongs to different group. Light patterns are controlled by PIC16F72 microcontroller which drives LEDs through ULN2003A driver chip. Driver chip is capable of sinking 500mA of current, so this parameter should be kept in mind when attaching multiple LED stripes in to long lines. Continue reading

Electronic LED dice with tilt sensor

There are many electronic LED dice projects around where you can choose the layout, triggering and circuit. This one has something a bit different from other. First of all PCB is round and LEDs are numbered instead of positioned to mimic physical dice. LEDs here are positioned in circular pattern that labeled from 1 to 6. When dice is rolled, LEDs display chasing effect and gradually slows down until it stops at one of LEDs. Dice is built around PIC12LF1822 microcontroller. LEDs are connected by using three wires (Charlieplexing). Dice can be triggered with tilt sensor by shaking the dice. It is powered with coin cell battery. There is a switch to turn on and off. If dice is left powered for long time, it automatically enters sleep mode to… Continue reading

Low cost home made plotter project

Probably many of you are thinking about how cool is to have CNC plotter or 3D printer. There kits and ready printers available for reasonable price. But still they are pricy for hobby use. But nothing is lost you like to build stuff. Hobbyprojects.com posted his progress in building plotter where he wanted things to be cheap and simple. He’s build all part separately by finding simplest and cheapest solution to rising problems. Some of his parts came from Epson printer. He also purchased used stepper motors from local junk store. The electronics part he built around PIC16F877 microcontroller. He built his own motor driver circuit out of discrete components, but it seems that results aren’t as good as it would be with specialized chips like Allegro A3984. Connection to… Continue reading