#PIC16F628A SERIAL PROGRAMMER HOW TO#
#PIC16F628A SERIAL PROGRAMMER MANUAL#
#PIC16F628A SERIAL PROGRAMMER SOFTWARE#

The programmable relay timer gets inputs from the 4 push buttons. The following figure shows the complete relay timer circuit soldered on a general-purpose prototyping board. The PIC16F628A pin assignments for the LCD, switches, relay and buzzer circuits are listed in the following table. PIC16F628A resonator and ICSP header connections Relay and buzzer control circuitįigure 4. I/O circuit with PIC16F628A pin assignmentsįigure 3. The I/O pins of PIC16F628A, the resonator connection, and the in-circuit serial programmer (ICSP) header are shown in Figure 4.įigure 1. The PIC16F628A microcontroller runs at 4.0 MHz using an external resonator. The relay and buzzer circuits are shown in Figure 3. The project also includes a DC buzzer that beeps when the relay switch changes its status.

The output relay switch is driven through a NPN transistor (2N2222).

#PIC16F628A SERIAL PROGRAMMER MANUAL#

S2 is another slide switch that allows manual control of the LCD backlight. The pin assignments for the LCD data and control signals are shown in Figure 2. The output LCD is a standard HD44780-based display and is driven in 4-bit mode. The status of the 4 input switches is read by the PIC16F628A microcontroller through ports RA2, RA3, RA4, and RB0.

#PIC16F628A SERIAL PROGRAMMER SOFTWARE#

Their functions will be described in the software section. The four input switches are named as Menu/+, Select, Enter, and Start/Stop. There are five tact switches in this project: one for microcontroller reset, and four for user inputs. S1 is a slide switch for turning the power supply on and off.įigure 2 depicts the input and output setup. Diode D1 (1N4001) is used for reverse polarity protection in the circuit. To minimize the heat dissipation in the voltage regulator, the recommended input DC voltage to LM7805 is 9V, which can be easily obtained from a DC wall adapter. The entire circuit runs off a regulated 5V power supply derived using the popular LM7805 linear regulator chip (Figure 1). The hardware part of this project is very simple. Interactive user interface using 4 tact switches and a character LCD.ON/OFF timing range: 0 to 99 hours and 59 minutes.OFF and ON time setup for the relay operation.Here are the summary of the features that this timer device has: The timer also saves the user inputs to its internal EEPROM so that it can retain these values after any power supply interrupt. The timing resolution of this relay timer is 1 minute. The programming menu and device status are displayed on a 16×2 character LCD. The device can be programmed through 4 push switches.

Another interesting feature of this project is it offers cyclic option, which means you can choose to run it in a continuous loop of ON and OFF cycles. The maximum time interval that you can set for on and off operations is 99 hours and 59 minutes. It allows you to set both ON and OFF time.

#PIC16F628A SERIAL PROGRAMMER HOW TO#

This article describes how to build a fully functional, one-channel programmable relay switch using the PIC16F628A microcontroller. Programmable relays find use in numerous automation applications such as automatic street light control, watering and pump control, HVAC, home automation, power plants automation in industries, etc.

Pic16f628a Serial Programmer