Introduction of 89Sxx
There are some 89Sxx development board, here is another one. I have designed this single side development board to be used as a tool for learning MCS-51 Microcontrollers, and for easy microcontroller project development.
The 89Sxx development board features :
89Sxx 40-DIL based design, 89S51/52/53
In System Programming (ISP) through the 6-pin header
RS-232 and RS-485 serial port (shared pin) for communicating with serial devices like PC
HD44780 compatible alphanumeric LCD connectivity with backlight control
4 on-board tact switch
16 general purpose IO port pins on 5×2 header (Port0 and Port2)
24Cxx I2C EEPROM
DS1302 serial Real Time Clock (RTC) with battery backup
On-board supply rectifier and voltage regulator
Single sided PCB design
Hardware Features of 89Sxx |
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The hardware block is shown in Figure 1. The MCU is 89Sxx microcontroller. And the complete hardware schematic is shown in Figure 2.
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Port1 is used as data-bus for LCD (4-bit interface, PCB lay-out for 16×2 character with backlight), on-board tact switch and connection for In System Programming (ISP)
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Port0 and Port2 as general purpose IO, are available for interfacing external devices. Port0 is connected with DIP switch, and also P0.0 and P0.1 are connected with opto-isolated input
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Port3, P3.0 and P3.1 are being used for serial communication UART, P3.2 for RS-485 control direction. P3.3 and P3.4 are serving as general purpose IO port pins. Another pins for communicating with serial chip, EEPROM, RTC and serial shift register (LED array indicator)
For more detail: 89Sxx Development Board using microcontroller
