3145 - DS18S20 Computer Serial Temperature Data Logger

4 channel temperature meter and data-logger for Dallas DS18S20 high precision 1-wire digital thermometer sensors. The temperature data, in degrees C or F, is output as a continuous data stream over an RS232 serial port. The board uses a pre-programmed microcontroller and can read up to four DS18S20 digital thermometers (1 is supplied - more can be purchased separately from us - see price panel below).

The DS18S20 has an operating temperature range of -55°C to +125°C and is accurate to ±0.5°C over the range of -10°C to +85°C. The sensors can be mounted up to 200metres away from the logger.

No external power is required (the kit is powered from the serial port).

The output data is a continuous stream in simple text format (sensor number followed by temperature reading to 2 decimal places). Simply capture the data to a text file and then import it into Excel to produce tables and charts of temperature readings over time.

The users can tailor the input data stream to suit their purpose - it may be dumped into an Excel spreadsheet, or they can write BASIC programs using the INPUT command to grab the readings.

As you can see from the pictures there is not much to the hardware (the PCB is just 45x45mm) and most of the work is done by the PIC.

Application Ideas

This board is an ideal use for old computers - continuous temperature data logging. A few ideas of how this circuit can be used as given below (additional equipment/software may be required):

• Simple weather reports for web pages
• Computer server monitoring
• Computer power supply temperature warnings
• Redundant critical systems monitoring
• House temperature monitoring
• Complex home automation tasks (start fan if warmer outside during Summer)
• Refrigerator monitoring and testing
• Brewing temperature regulation
• Fish tank heater verification
• Microclimate logging (ground versus air temperature)
• Daylight sensing (LDR on digital input)
• Primitive locking (using serial number)

• User Manual
• DS18S20 Data Sheet

• The product is supplied with one DS18S20 sensor. You can purchase additional sensors to populate the three remaining positions at GB£4.95 each (see below)
• Cable for sensor connection (Order Code Order Code CAB859 or CAB588)
• M-F Serial Port Lead (Order Code LDC441)
• optional PCUSB6 for USB connection
• Can be used with our optional Serial Input RF Data Link Transmitter (Order Code 3173) and Serial Output RF Data Link Receiver (Order Code 3174) to create a remote wireless link to the PC

Product Format

• This item is available in PRE-ASSEMBLED Electronic Module (AS) only more