Introduction

I have designed this leaning board to be used as a tool for learning MCS-51 Microcontrollers.

The AT89Sxx learning board features,

• Designed for new ISP chips, 89S51, 89S52, and 89S53, 40-pin DIP,
• In System Programmable (ISP) through the 6-pin header and a jumper, (no need external programmer),
• TxD and RxD serial port for communicating with serial devices,
• 32 bit GPIO,
• Onboard rectifier and +5V DC voltage regulator,
• Single Sided PCB design.

Hardware

The board design is kept as simple as possible so that everone can make the learning board easily. The schematic shown below shows the complete hardware schematic of the AT89Sxx learning board. PORT0, PORT1, PORT2, and PORT3 are available for interfacing external devices. P3.0 and P3.1 are being used for RS232 interface.

Components:

R1                          330 1/4W +/-5%

R2                          10K 1/4W +/-5%

R3-10                     10K 1/4W +/-5% (for pull up on P0)

C1                         1000uF/16V electrolytic capacitor

C2                         100uF/16V electrolytic capacitor

C3                         100nF multilayer or ceramic

C4                         10uF/16V electrolytic

C5,C6                    33pF ceramic

D1                         1N4001 / 1N4002 silicon rectifier diode

D2                         LED

U1                         LM7805, voltage regulator

U1                         AT89S51, AT89S52 or AT89S53

X1                         Crystal 1MHz – 33MHz (11.0592MHz is suitable for standard BAUD rate generator using timer1, says 9600 )

DB25 parallel port, 25pins connector

Construction

In order to make the AT89Sxx learning board, download the PCB ZIP file click on PCB ZIP FILES link given below. The file contains the single sided PCB track layout in PDF. Use the convenient file for making the PCB. Put the components as shown in the picture shown below.

How to make PCB?

1. You can print the PCB file. I have designed it using Express PCB (freeware)

   

2. Then copy with copier machine on tranparant paper. If you have a laser printer, you can print it on transparant paper or glossy photo paper.
3. After that, pell on PCB with clothes Iron.
4. After 5-15 minutes I turn off the clothes iron and remove the board to let it cool down.
   It needs to cool down because it is quit hot (30-40 degree Celcius)
5. Remove the paper form PCB. You can see how I am removing that paper. Movie file

Code Programming

The SPI In system Programming adapter such as Cheap Loader Cable of Asim’s ISP for 89S51 89S52 can be used for program loading to the MCU. Connect the ISP adapters 6 pin connector with the 6 pin ISP header on this board. Run the ISP software on PC for sending the Intel hex file to microcontroller. Then program will start running.

Project by Tahan Prahara, prahara_satria@yahoo.co.id

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