They’re “digital” because you can control the resistance over its range programmatically, by sending it commands over a 2-Wire (I2C/TWI) serial interface. So, that means that you can hook it up to some microcontroller, like the Arduino, and adjust the resistance in a little program. The DS1803-010, means it has a range of 0-10K Ohms.
DS1803 Digital Potentiometer: [Link]
This project make use of a PIC16F628(A) and a DCF77 receiver from Conrad. Optional there is a possibility to connect an electronic gong on it. Every second is on PORTA.1 (pin 18) a pulse from 0.5 second. This signal isn’t necessary for anything, but maybe you want to connect a LED on it, so that these wil blink every second, or a piezo buzzer, so that the clock ticks as an analog clock.
Overall the project is great and someone put allot of work into designing it.
Digital DCF77 clock with LCD and gong: [Link]
This simple circuit is designed to report the temperature via any standard FM broadcast band radio at regular intervals. It uses a simple low bit rate tone signalling scheme which can be interpreted easily by both humans and machines. Such a device can be used stand-alone or as part of a PC-based weather station or HVAC system.
There are endless practical applications for such a device, just think about how many time you wanted to measure a temperature and for that you needed to run wires to the sensor. Now with this circuit you can place the device where you need the temperature reading and no more wires need to be connected.
Wireless Digital Thermometer: [Link]
This 3-digit digital thermometer is easy to build for beginners or hobbyits. PIC16F628 is used to read digital values of temperature from a DS1820 sensor. All 7-segments are driven by a power logic 8-bit shift register TPIC6B595 with open collector output. For the 7-segment we need 12V volt to drive it because it has 3 LED per one segment. Source code in C Compiler is available.
3-Digit Digital Thermometer: [Link]
Interfacing an Analog-to-Digital Converter (ADC) with Linux via the parallel port is fairly simple. There two major areas that need to be addressed - hardware and software. The hardware consists of the parallel port, an ADC, and an analog signal source. The software we programmed in ‘C’ language.
Interfacing Your Computer to an ADC via the Parallel Port: [Link]
