Yet another darkroom timer using a PIC 16F84A. All the functions are in firmware:
Lamp(s) light at start of timing and turn off when timer reaches zero.
A set of leds were added between the minute and second leds which blink during timer operation.
7 segment displays include tails for digits 6 and 9.
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The light level can be adjusted with two push-buttons “Up” and “Down”. Controller in this application is PIC16F84 that drives BUZ11 mosfet. Dimmer is tested with a light bulb 12V/4W and mosftet didn’t get even warm (which was expected since the datasheet says: 50V/30A).
Source: Elektronika.ba (niho)
Forum post: Digital light dimmer
From the displayed patterns can be seen that the relays connected to the RB ports on the microcontroller and the RB3 – RB6. Over MAX232 interface circuit is connected to the serial port of your PC. Command is done the program done in Visual Basic in the PC. Led6 uses LEDs for indication of incorrectly [...]
From the displayed patterns can be seen that the relays connected to the RB ports on the microcontroller and the RB0 – RB3. As the use TSOP1736 IR receiver or similar to it. Leadership is done remote control that supports the Philips RC5 standard.
Source: Milan Milovanovic
Introduction
When I set, some time ago, about working with a PIC 16×84, I had immediately to face the problem to have a permanently and stably working circuit, without mounting the PIC [...]
The purpose of this timer is to provide a countdown time from 1 second to 99 minutes & 59 seconds. I use it to control the lighting for the Ultra-Violet exposure of photosensitive PCB material. The project provides also an audible alarm at the end of the countdown time and switches the [...]
GSM call alarm is a device that will call a destination number via Siemens or Ericsson GSM phone (19200 bps RS232). It has 1 sensor input and another input – state (stanje). If state input is = 0V than the device is “active” and it monitors the sensor input. The device is deactivated when state [...]
Download Project Files: VGA – Video Tester with PIC16F84
Source: RadioKot
All resistors are 1/4W.The circuit is powered by 9…15V DC or AC. When In Circuit Programming (ISP) connectors are used, is possible the programmer to be powered from target’s power source. Diodes D2 and D6 protect the regulator LM7805, when target’s power is used.
‘ XTAL JUMP ‘ is used to cut XTAL when the AVR [...]
This project allows instant start sequentially but a dozen low-voltage lamps 12 V / 60 W, and makes them fade and always sequentially (but slower). This system has been designed to meet the demand of a visitor who wanted ten recessed low voltage spot in a driveway to his house, with the following function: – [...]
This circuit allows switching on a LED when the battery voltage (12V) drops below a certain threshold. The operating system is based on a comparison of tension, which comes in a zener diode. If the supply voltage is 12V and the zener diode is a 10V model (this is the case in the diagram), we [...]
This is a good looking and practical device that can be useful in many areas where countdown timer is needed. This project is based on the PIC16F84A microcontroller. The time range can be adjusted between 1 and 999 seconds. This project has 3 buttons and one of them is named Set Button. In order to [...]
A VU meter is often included in audio equipment to display a signal level in Volume Units; the device is sometimes also called volume indicator (VI). In this project we are building a basic and low cost LED VU Metre circuit . The extent (range) display is -18 dBu to +3 dBu, spread over [...]
Today we have a new category “Projects” and a new electronic project 12 Channel LED Chaser with PIC16F84A.
This project is based on the popular PIC16f84A micro-controller.The heart of this project LED chaser is the PIC16F84A PIC microcontroller.A 4MHz crystal and capacitors C1 and C2 22pf is used for providing clock pulses to the micro-controller. The [...]
