Project Board for SST89E516RD Microcontroller
Wichit Sirichote, firstname.lastname@example.org
Project board using SuperFlash SST89E516RD microcontroller. In Applications Programming, no need external programmer!
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.
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
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 .
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,
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)
2 October 2017