This paper proposes a hardware circuit design based on STC microcontroller learning platform, adopts a new type of single-chip model STC12C5410AD, and adds some serial interface chips to the learning platform. The interface standards include RS-232, SPI, IIC, 1-wire and so on. Learning platform design goals: ISP programmable, LCD display, calendar clock (IIC interface chip), temperature measurement (1-wire interface chip), FLAH memory (SPI interface chip), button (wax change scan button), voltage measurement (AD conversion).
1 hardware system overview
The learning platform is based on STC12C5410AD, and the structure is shown in Figure 1.
1.1 Introduction to STC12C5410AD Microcontroller
STC12C5410AD single-chip microcomputer is an enhanced single-chip microcomputer which is introduced by Hongjing Technology on the basis of the standard 8051 microcontroller core. It is an enhanced 8051 microcontroller, single clock / machine cycle, operating voltage 5.5V - 3.5V, operating frequency range 0 ~ 35MHz, 512 bytes of on-chip data memory, 10K bytes of on-chip Flash program memory, ISP (in the system Programming) / IAP (programmable in the application), can directly download the program through the serial port, EEPROM function, 6 16-bit timer / counter, PWM (4 channels) / PCA (programmable counter array, 4 channels), 8 channels and 10 bits A/D conversion, SPI synchronous communication port.
2 hardware system design
2.1 crystal, power supply and reset circuit
2, 3, and 4 are a reset circuit, a power supply circuit, and a crystal oscillator circuit, respectively. The RST network label in the reset circuit is connected to pin 3 of the STC12C5410AD microcontroller, which is powered-on reset. Since the operating voltage of the STC12C5410AD microcontroller is between 5.5 and 3.5V, the power supply uses a 5V switching power supply. For accurate AD conversion, an LM7805 regulator chip is added.
Closed cell conductive EPDM Rubber Sponge
-EMI/RFI Shielding
- Can be used as grounding applications
- Conduct electrons throughout the material
- Pressure Sealing at low pressure
- Most Economical material compare with silver coated elastomers
- Temperature Stability between -40°C to 125°C
- Nuclear Bio Chem Resistance
- Salt Fog Resistance
Applications:
Electronic devices, Cable box, Satellite Box, Cellphone, Network Routers, Semiconductor, Gaskets, Computer Enclosures, Hand Held Devices, Medical Diagnostic, and Analytical Equipment, Aerospace & Automotive, Electronic Systems.
EPDM
Rubber Sponge
Specification
Typical
Value
Compression
at 25% deflection (kPa):
35-65
49
Compression
deflection at 50% (kPa):
80-160
112
Density
(kg/m³):
120+/-20
134
Compression
set (50% 22H 20°C):
25% Max.
14.1%
Water
Absorption, max. change in weight (%):
10
0.6
Heat
ageing, change in compression deflection, 22hrs at 100°C:
+/-30%
PASS
Flammability:
FMVSS-302
PASS
Elongation
at break (%):
N/A
180
Tensile
strength (kN/m²):
N/A
>500
Temperature
range (low-high):
N/A
-40 to +70°C
High intermittent:
N/A
+100°C
Resistance
to Air and UV:
EXCELLENT
Resistance
to Oil:
POOR
Resistance
to Acids:
GOOD
Environmental
Protection:
CFC AND HFC FREE CAN
BE RECYCLED
SPECIFICATION DATA
Conductive Epdm,Rfid Conductive Epdm,Rfi Conductive Epdm,Anti Static Conductive Epdm
JINAN EMI SHIELDING TECHNOLOGY CO., LTD. , http://www.emirfi.com