Posted on Monday, December 19, 2011 • Category: PIC
Here is 0 to 99 minutes relay timer using PIC16F628 microcontroller and 16 character LCD display. The microcontroller is PIC16F628A running at 4.0 MHz clock using an external crystal. An HD44780 based 16×2 character LCD is the main display unit of the project where you can watch and set the timer duration using tact switch inputs. There are three tact switches connected to RB0 (Start/Stop), RB1 (Unit), and RB2 (Ten) pins. You can select the timer interval from 0-99 min using Unit and Ten minute switches. The Start/Stop switch is for toggling the timer ON and OFF. When the timer gets ON, a logic high signal appears on the RA3 pin, which can be used to switch on a Relay. The circuit diagram of this project is described below.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]