Pazzy

Hello guys. Today I will guide you how to make a Digital Thermometer Circuit using IC DS18B20 and PIC 18F4550. I also provide you the source code of this project. Thank you for reading my blog :) Digital Thermometer Circuit Please go through the characteristics of IC DS18B20 and PIC 18F4550 that can be used to make a Digital Thermometer Circuit first and then run the code below. For PIC18F4550: - Flash: 32K bytes - Single-Word Instructions: 16384 - SRAM: 2048 bytes - EEPROM: 256 bytes - I/O: 35 - 10-Bit A/D (ch): 13  Y Y 1 - CCP/ECCP (PWM): 1/1 - SPP: Yes - SPI: Yes - Master I 2C™: Yes - EAUSART: 1 - Comparators: 2 - Timers 8/16-Bit: 1/3 Special Microcontroller Features: • C Compiler Optimized Architecture with optional Extended Instruction Set • 100,000 Erase/Write Cycle Enhanced Flash Program Memory typical • 1,000,000 Erase/Write Cycle Data EEPROM Memory typical • Flash/Data EEPROM Retentio...

This circuit stores a single morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter. The keyer can output either a one-shot message such as "CQ DX DE CALLSIGN", or a continuous message. The continuous mode is useful for making low power (QRP) beacons. A One-shot message is controlled by the start/stop buttons, a continuous message is sent by turning on the free run switch. EPROMs other than the 2732 can be used if suitable changes are made to the circuit. For larger EPROMs, just ground the higher order address input lines on the EPROM chip, and wire the appropriate chip select pins for outputs enabled and chip selected. It is also possible to store more than one message in different banks of a larger EPROM, for instance, if a 2764 part were used, the A12 address line could be used to select the upper or lower message. Theory CMOS Nor gates U1c and U1d form a gated astable clock oscillator, the frequency can be adjusted by po...