Project Board for SST89E516RD Microcontroller

Wichit Sirichote,

Project board using SuperFlash SST89E516RD microcontroller. In Applications Programming, no need external programmer. New version with Buzzer and USB 2.0 by CH340E module !

The project board using SuperFlash SST89E516RD has been developed. The board provides 12-bit ADC, four digits 7-segment display, 16x2 LCD display, keypad and USB-UART interface. The board uses +5V power supply from USB port. The hex code loading can be done by IAP (In Application Programming) feature. The USB-UART chip, CH340G was used to interface between TTL UART port and PC USB port. This design cuts the MAX232 chip and enables USB interface to the new PC easily. This USB port can be used for both UART communication and firmware downloading.

Block diagram

The PCB layout is very nice square design. Main components are:

1. SST89E516RD microcontroller, 64kB Flash memory,
2. MCP3202, 12-bit SPI interface Analog to Digital converter,
3. CH340G, USB-UART interface chip,
4. LTC4727, super bright 4-digit 7-segment display,
5. 16x2, text LCD module.
Figure 1: Hardware block diagram

Hardware description

The SuperFlash microcontroller, U2 SST89E516RD is configured in single chip mode. EA is tied to +5V. The XTAL frequency is set to 12MHz. The X2 oscillator signal, 12MHz was fed to U4 USB chip. U1 is LTC4727 super bright 7-segment display. Segment driven is done by P0 with 1k pull-up resistor. P2.0-P2.3 drives digit common pin with logic low. Keypad, SW1-SW4 triggers P2.4 low under display scanning. D2, +5.1V zener protects P2.4 from spike voltage.

JR1 is 16-pin header for text LCD interface.
Figure 3: Hardware schematic (click to enlarge). 

Hex code loading with EasyIAP

Before we can use the project board, we need to install the CH340 USB chip driver.

The USB cable is micro USB plug. When connect it to the PC, Windows will assign the COM port automatically. We can modify the port number for the EasyIAP using properties (right click), port settings/advance. Under EasyIAP, choose OPTION for the assigned COM port number. The example below shows COM2 has been assigned.
Figure 4: USB-SERIAL CH340 as the COM2 port.

Steps for loading the hex code to the microcontroller chip is described in details here, EasyIAP .

8051 Assembly Language Programming

The 8051 project project board can be used for learning how to program 8051 chip with Assembly langauge.

Download the Assembly Programming Manual , Assembler Tool

Using the Mikro-C for 8051

The 89E516RD chip has 64kB code memory and 1kB external RAM. This memory size is suitable for c coding. Mikro-C for 8051 is very nice tool for developing the project using c language.

We can select the AT89C51RD2 chip with 12MHz oscillator for project file settings. Memory model is SMALL for single chip operations. The chip has the same size flash memory, 64kB. The x2 mode is also the same. x2 mode will run using 6 clocks for one machine cycle.
Project file settings

Sample C programs

1. LED blinking.c, makes the debugging LED, D1 blink with small delay.
2. SEVEN1.C 7-segment display, scans 4-digit display.
3. UART.C, uses Timer2 for BAUD rate settings, 9600 8n1.
4. Scan2.c scans display and keypad. Display 8051 on 7-segment display. Make debug LED ON when key was pressed. Scan2.hex, hex file for testing.
5. Displaynum1.c, displays number on 7-segment.
6. Lcd1.c, displays texts on 16x2 text LCD module using 4-bit interface LCD library.
7. myclock.c, simple digital clock using timer0 interrupt. Can be adapted to be clock controller!, myclock.hex
8. SSTadc.c, display 12-bit ADC readings, 0-4095 for 0 to +5Vinput.
9. Voltmeter.c, display 0 to +5.00V using linear calibration curve.


Download CH340 USB chip driver, EasyIAP Rev.6 , FlashFlex Microcontroller datasheet, FlashFlex parallel programming , BSL11F boot-strap loader User's guide

Schematic, Bill of Materials (BOM)

User's Manual

Assembly Programming Manual

8051 Project Board V2.0 (CH340E module + buzzer)

The new version 8051 project board uses CH340E USB-TTL converter module. The CH340E has internal oscillator and built-in microUSB connector. J1 provides SPI signals for interfacing the SPI boards.

Additional small buzzer connected to P3.7 is available for alarm application.

U9 is the CH340E USB-TTL converter module.


TXD pin is tied to RXD pin of the MCU and RXD pin is tied to TXD of the MCU pin. The USB +5V provides power supply to the board. Q3, BC557 PNP transistor drives the buzzer with P3.7 bit.

Sample C programs with buzzer

1. beep.c, makes beeping every 0.5s.
2. morse1.c produces MORSE code sending "CQ 8051"
3. lcd3.c sample program displays text on the LCD
4. Test1.c, hardware testing, displays 8051 and produces Morse code sending "CQ 8051", Test1.hex ready for code loading

The project board with 16x2 LCD display

Using power bank as the power supply.

Sample code and experiment with sensor modules and actuators, click below link.

Interfacing the 8051 Project Board with sensor modules and actuators



U1 LTC-4727
U2 SST59E516RD, 64kB Flash Microcontroller
U3 MC3202, 12 bit Analog to Digital converter
U9 CH340HW-728, USB-TTL converter
D1 3mm LED
D2 1N4733 5.1Vz 1/2W
Q3 BC557, PNP transistor

Resistors (all resistors are 1/8W +/-5%)

R1 330
R2 5
R3,R5 10k
R6,R7,R8,R9 100


C1,C2 30pF ceramic capacitor
C5,C3 10uF 16V, electrolytic capacitor
C10,C4 10uF 16V
C7,C8,C11 0.1uF, multilayer capacitor
C12 100nF, multilayer capacitor

Additional parts

LS1 BUZZER, +5V magnetic buzzer
Q1 12MHz, Xtal
SW1,SW2,SW3,SW4, 20mm TACT switch

Pre-built and tested plus USB cable for 8051 Project board v2.0 is only $30 with free shipping. PayPal is accepted.

Please contact:

Download: Bootloader with testing code (only parallel programming)


Last updated, 21 March, 2020

2 October, 2017