Electronic Notice Board
SMS BASED WIRELESS NOTICE BOARD
1. SPECIFICATION
1.1)AT89S52 MICROCONTROLLER: MAJOR SPECIFICATIONS:
• 8K Bytes of In-System Programmable (ISP) Flash Memory – Endurance: 1000 Write/Erase Cycles
• 4.0V to 5.5V Operating Range
• Fully Static Operation: 0 Hz to 33 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Eight Interrupt Sources
• Full Duplex UART Serial Channel
• Low-power Idle and Power-down Modes
• Interrupt Recovery from Power-down Mode
• Watchdog Timer
• Dual Data Pointer
• Power-off Flag
• Fast Programming Time
• Flexible ISP Programming (Byte and Page Mode)
• Green (Pb/Halide-free) Packaging Option 1.2)MAX232 IC:
MAJOR SPECIFICATIONS:
Input supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 6V
Positive output supply voltage range, VS+ . . . . . . . . . . . . . . . . . . . . . VCC − 0.3 V to 15 V
Negative output supply voltage range, VS− . . . . . . . . . . . . . . . . . . . −0.3 V to −15 V
Input voltage range, VI: Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC + 0.3 V
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V
Output voltage range, VO: T1OUT, T2OUT . . . . . . . . . . . . . . . VS−( − 0.3 V) to VS+( +0.3) V
R1OUT, R2OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC + 0.3 V
Short-circuit duration: T1OUT, T2OUT . . . . . . . . . . . . . . . . . . . . . . . . . Unlimited
Package thermal impedance, θJA : D package . . . . . . . . . . . . . . . . . . 73C/W
DW package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57C/W
N package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. SPECIFICATION
1.1)AT89S52 MICROCONTROLLER: MAJOR SPECIFICATIONS:
• 8K Bytes of In-System Programmable (ISP) Flash Memory – Endurance: 1000 Write/Erase Cycles
• 4.0V to 5.5V Operating Range
• Fully Static Operation: 0 Hz to 33 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Eight Interrupt Sources
• Full Duplex UART Serial Channel
• Low-power Idle and Power-down Modes
• Interrupt Recovery from Power-down Mode
• Watchdog Timer
• Dual Data Pointer
• Power-off Flag
• Fast Programming Time
• Flexible ISP Programming (Byte and Page Mode)
• Green (Pb/Halide-free) Packaging Option 1.2)MAX232 IC:
MAJOR SPECIFICATIONS:
Input supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 6V
Positive output supply voltage range, VS+ . . . . . . . . . . . . . . . . . . . . . VCC − 0.3 V to 15 V
Negative output supply voltage range, VS− . . . . . . . . . . . . . . . . . . . −0.3 V to −15 V
Input voltage range, VI: Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC + 0.3 V
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V
Output voltage range, VO: T1OUT, T2OUT . . . . . . . . . . . . . . . VS−( − 0.3 V) to VS+( +0.3) V
R1OUT, R2OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC + 0.3 V
Short-circuit duration: T1OUT, T2OUT . . . . . . . . . . . . . . . . . . . . . . . . . Unlimited
Package thermal impedance, θJA : D package . . . . . . . . . . . . . . . . . . 73C/W
DW package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57C/W
N package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .