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

Programmable Timer on a PIC18F4550

Victor got forced into building this project because a 30+ year old mechanical timer for the house heating gave up on them – instead of buying a new one, he decided to learn new stuff and build something digital. After talking to a few people he used a PIC18F4550 along with a Dallas Maxim DS1307 real time clock. The chips communicates through I2C and to still keep time even if power goes off a back up battery is used. Now you need to have something to display the time stuff – this project comes with a 16×2 liquid crystal display (that also comes with a backlight!). You would also need something to control and adjust the time – this comes with six momentary switches. As I mentioned earlier this was built for a heater so Victor threw in an LED (Light Emitting Diode) to indicate if the heater is on or not. Continue reading

PIC counts down from 9999 seconds

Sometimes you may need simple countdown timer that is easily configurable and used. Take a look at 0-9999 seconds countdown timer that is based on PIC12F683 microcontroller and displays its current value on four seven segment LED displays. In order to drive LED display there is a MAX7219 driver IC used. Timer can be set using couple if push buttons – one for incrementing time value and another for starting timer. Once timer reaches 0 value it sounds alarm using buzzer. Continue reading

A programmable timer using PIC16F628A

People are just too lazy – that’s why the remote control was invented anyway. Some aren’t lazy at all yet they still have unnecessary power consumptions due to the fact that they forget turning things off. To alleviate the problems concerning timed functions the timer was invented – obviously the name tells the story. A very useful piece of work, yet not all appliances have a timer built into them. This particular project is a simple yet elegant way to cut unnecessary power expenses by turning things on and off for a specific span of time. It harnesses the power of PIC16F628A to control a single pole double throw relay that is capable of operating at AC line voltages while keeping time at the same time. The timer comes with an LCD to indicate the amount of time left before the relay changes state; it also has buttons to be able to adjust the time. Continue reading

Countdown timer for PCB exposure

Countdown timer can count fro m1 second up to 99 minutes and 59 seconds. Ideal tool for PCB maker when need to control PCB exposure with ultraviolet light. Timer is equipped with alarm when countdown finishes.   Timer has it own power supply unit, so you can plug it to AC outlet and start counting. The counter is based on old good PIC16F84 which counts time and drives 4 seven segment LED displays. Timer can be controlled by three buttons. One Starts/Stops timer, second sets time for each of digits, and last button allows to select preset times from EEPROM-convenient for quick time select. Project files are available for download. Continue reading