tvdl @ instructables.com writes:
This is a small project to get you started with the electric imp and a Thermistor so you can see how you can get temperature readings updating live on a web site. This instructable will address both the hardware and the web site along with all the parts in between. I’ve tried to keep it as simple as possible which means there are plenty of ways you can expand on it.
The first part will address the electric imp and how we connect a resistor and Thermistor to create a very simple circuit called a voltage divider and use the imp’s built in analog to digital converter to take a reading and calculate what the temperature is. I’ll also go into some detail on how the circuit and it’s components work.
Simple wireless temperature sensor updating web site with Electric Imp and Thermistor - [Link]
Ktulu_1 @ instructables.com writes:
The temperature in my office at work varies quite a bit depending on the time of day, season, and the whims of the other people I share the floor with. When I’m sitting at my desk shaking uncontrollably or sweating profusely it would be nice to know if it’s due to the temperature or just work related stress. A simple $5.00 thermometer would suffice, but where’s the fun in that? Making my own thermometer might cost ten times as much, but I might learn something in the process and it would be way cooler than any cheap store bought thing? I’d rather make something myself even if I have to pay a “maker’s premium.”
Tempduino – Arduino Based Temp and Humidity Display - [Link]
This tiny little breakout board has Microchip’s 24LC512 EEPROM and MCP9802 temperature sensor devices, both of which support I2C protocol. This board can be used for both sensing the ambient temperature and storing it. The MCP9802 is a digital temperature sensor with an user-selectable resolution from 9 to 12 bit. It can measure temperature ranging from -55°C to +125°C and notifies the host microcontroller when the ambient temperature exceeds a user programmed set point through its ALERT output pin. This board allows you to store up to 32000 temperature samples when you use the sensor in high resolution mode (12-bit, 0.0625°C) with each sample stored as two bytes. Raj (from embedded-lab.com) is selling this board for $9.00 on Tindie.
I2C EEPROM plus Temperature Sensor breakout board - [Link]
Temperature, pressure, humidity, flow – all this you have under control with the Sensirion components, the top quality Swiss producer.
CMOSens technology and other innovative technologies of company Sensirion enabled production of top quality calibrated sensors with a long lifetime. As you may have read in our articles:
- New sensors Sensirion will take you only 3x3mm on PCB!
- Professional humidity and temperature measuring with calibrated sensors Sensirion
- Professional solution for accurate measurement of humidity and temperature
or other. Sensirion sensors in fact aren´t sensors but ready-made solutions with a sensor, preamplifier, AD converter and a communication interface. The result of this concept is high disturbances immunity, high accuracy, saving of components and a simplified development.
Do you develop an application, where you´d use Sensirion components?
As we are an authorized Sensirion distributor, we´re able to provide you with free samples of many Sensirion components, especially RH&T and pressure sensors.
Describe us your industrial project in which you´d like to use a given component and let us know at firstname.lastname@example.org.
Soselectronic supports your development with free samples of Sensirion sensors! - [Link]
This project is about building a microcontroller-based digital room thermometer plus hygrometer that displays temperature and relative humidity on 4 large (1 inch) seven segment LED displays which adjust their brightness level according to the surrounding illumination. It consists of a closed loop system that continuously assesses ambient light condition using an inexpensive light-dependent resistor (LDR) and uses that information to adjust the brightness of the display. An inexpensive DHT11 sensor is used to measure temperature and relative humidity. The microcontroller used in this project is PIC16F688, and it runs at 4 MHz clock generated from its internal source. A separate display driver chip (MAX7219) is used to control and refresh the display data on the seven segment LEDs.
TrH Meter: A DIY indoor thermometer plus hygrometer with adaptive brightness - [Link]
When specifying a reference, keep in mind that initial accuracy, temperature coefficient and long-term stability all play a role in overall accuracy of the finished product. By taking some care in applying the reference, and by avoiding some key pitfalls, the reference’s inherent accuracy can be preserved.
Using and understanding voltage references - [Link]
The MAX31855 performs cold-junction compensation and digitizes the signal from a K-, J-, N-, T-, S-, R-, or E-type thermocouple. The data is output in a signed 14-bit, SPI-compatible, read-only format. This converter resolves temperatures to 0.25°C, allows readings as high as +1800°C and as low as -270°C, and exhibits thermocouple accuracy of ±2°C for temperatures ranging from -200°C to +700°C for K-type thermocouples. For full range accuracies and other thermocouple types, see the Thermal Characteristics specifications in the full data sheet.
MAX31855 – Cold-Junction Compensated Thermocouple-to-Digital Converter - [Link]
Ultra-Accurate Temperature Sensor Offers ±0.5°C (max) Accuracy Over a Wide -40°C to +105°C Range
The MAX31725 temperature sensor accurately measures temperature and provides an overtemperature alarm/interrupt/shutdown output. This device converts the temperature measurements to digital form using a high-resolution, sigma-delta, analog-to-digital converter (ADC). Accuracy is ±0.5°C from -40°C to +105°C. Communication is through an I²C-compatible 2-wire serial interface.
The I²C serial interface accepts standard write byte, read byte, send byte, and receive byte commands to read the temperature data and configure the behavior of the open-drain overtemperature shutdown output.
MAX31725 – ±0.5°C Local Temperature Sensor - [Link]
The MAX44006/MAX44008 integrate six sensors in two products: red, green, blue (RGB) sensors; an ambient light (clear) sensor; a temperature sensor; and an ambient infrared sensor with an I²C interface. These highly integrated optical sensors include a temperature sensor to improve reliability and performance.
The devices compute the light information with six parallel data converters allowing simultaneous light measurement in a very short time. The devices consume only 15µA (MAX44006) and 16µA (MAX44008) separately in RGBC + TEMP + IR mode, and also have the ability to operate from 1.8V/3.3V/5.5V supply voltage rails.
RGB Color, Infrared, and Temperature Sensors - [Link]
Controlling temperature has been a prime objective in various applications including refrigerators, air conditioners, air coolers, heaters, industrial temperature conditioning and so on. Temperature controllers vary in their complexities and algorithms. Some of these use simple control techniques like simple on-off control while others use complex Proportional Integral Derivative (PID) or fuzzy logic algorithms. In this project Shawon Shahryiar discusses about a simple control algorithm and utilize it intelligently unlike analogue controllers. Here are the features of this controller:
- Audio-visual setup for setting temperature limits.
- Fault detection and evasive action.
- Temperature monitoring and display.
- Audio-visual warning.
- System status.
- Settable time frame.
- Data retention with internal EEPROM memory.
Intelligent temperature monitoring and control system using AVR microcontroller - [Link]