This project describes how to measure temperature with Atmega8 and a thermistor and display it on a Nokia 3310 LCD. A thermistor is a device that changes its resistance with temperature. With a proper resistor divider network, the temperature can be measured by measuring the voltage across the thermistor. [via]
AVR displays body temperature on a Nokia 3310 LCD – [Link]
hwydd is a small object (actually half a ping pong ball), interacting with its owner and environment. The object permanently aggregates light samples (i.e. it measures the every second and stores the average every some seconds). If you take it into your hand it notices the raise in temperature and tells you how it experienced the day (i.e. playing back the light levels of the day in time lapse). Check the video to better understand how it works.
hwydd: How was you day, darling? – [Link]
This project shows how to use the BMP085 Barometric Pressure Sensor with Arduino. The BMP085 pressure sensor combines a absolute barometric pressure sensor (aka barometer) with an temperature sensor and communicates with arduino using I2C protocol.
Arduino & Barometric Pressure Sensor BMP085 - [Link]
This is a temperature and humidity sensor with serial output that can be read with a computer. An LCD display could be used with minor modification. The unit is based on Atmega8 microcontroller. It uses LM335AZ temperature sensor attached to AVR ADC port and NONEYWELL HCH-1000-002 humidity sensor. [via]
Temperature and humidity sensor with serial output - [Link]
This project is a temperature controlled FAN based on LM311 IC. The fan is activated only when it is necessary. Working temperatures are 0C to 150C.
Temperature control circuit – [Link]
Pretty much every time I tried to work with some sort of digital interface I run into some kind of trouble where a logic analyzer would have saved me hours of blind debugging and posting to various forums. Same thing happened when I decided to try the TMP121 temperature sensor from TI which has an SPI interface. It was the first time I worked with SPI on a pic32 and as expected nothing worked for the first try. The code for setting the SPI interface and reading from it seemed correct, I took it from the “32 bit peripheral lib user guide” from Microchip.
So what else could be wrong ? Well at this point it could be a faulty sensor or incorrect use of the SPI interface maybe I wasn’t generating the clock correctly or maybe some wiring issue. This is the point where you need to have a logic analyzer.
Logic Analyzer on PicKit2 – [Link]
This is a simple USB temperature probe that uses the AVR USB library by Objective Development (http://www.obdev.at/avrusb/). It is in large part built upon the EasyLogger example by Christian Starkjohann. Whereas EasyLogger would send the data values over a keyboard interface, this project uses a custom device class and reads values using the ruby-usb library.
Temperature probe using AVR-USB - [Link]
This project is a wireless temperature and humidity sensor based on Sensirion SHT15 sensor and PIC18F1220. The unit is wirelessly sends the readings to a base station to display and log the data. The wireless link is implemented using XBee RF modules.
Wireless Temperature and Humidity Sensor – [Link]
This project is a wireless temperature and humidity sensor with USB interface based on obdev’s RemoteSensor example and their firmware-only USB implementation. The main change is the replacement of the analog sensors with a Sensirion SHT11 digital temperature and humidity sensor. The sensor unit consists of an ATTiny45 microcontroller, a SHT11 sensor, and a hoperf RFM12 868 MHz transceiver module. Check details on the link below.
Wireless temperature and humidity sensor with USB interface – [Link]
This project is a device that accurately measures temperature inside a Styrofoam enclosure and compare it to external temperature. To accomplish this it is utilizing the 8 ADC channels of the ATMega48 and used its in-chip USART capabilities to send this data to a PC for logging.
It’s basically a combination of several projects (microcontroller, temperature measurement with LM335, USART serial port communication, data visualization) for minimal cost. (It’s part of a larger project, but it turned out so nicely that I think it’s a good project in itself!) Many of the temperature sensor pages out there are complicated (using segmented displays or LCD screens), don’t log the data easily, or use expensive components. Also, this project was designed (though not yet tested) to allow 8 sensors to be read simultaneously. Check details on the link below.
Serial Port Multi-Channel Temperature Measurement – [Link]