bogdan @ electrobob.com wanted to know how much heat a heatsink can dissipate so he build a simple setup using a temperature sesnsor and a mcu. He writes:
It’s quite a common problem when building electronics that some components need cooling which is usually done through some sort of heatsink and optional fans. Choosing the right cooling solution can be a difficult task because the real life behavior of the system is hard to predict or model. In my case I have faced the simple question quite a few times: how much heat can a cooling system dissipate? The thermal resistance of a particular heatsink may vary quite a lot depending on the surroundings or it can simply be unknown to start with. The aluminum side wall of an enclosure made me build this thing.
This is why I have made this little device: a thermometer, a transistor and a microcontroller with a simple command line interface. I could have answered my questions in quite a lot of simpler ways, but since I made a simple thermometer not much else is needed to control the transistor when a DAC is available in the microcontroller.
Heatsink Tester – [Link]
The BME280 Integrated Environment Unit from Bosch Sensortec combines sensors to detect temperature, humidity and barometric pressure in a single 2.5 mm square 8-pin LGA package.
The chip has a quoted absolute temperature accuracy of ±0.5˚C at 25˚C and its pressure sensor features a measurement range between 300 and 1100 hPa. The relative accuracy of the pressure reading is ±0.12 hPa (equivalent to an error of ±1 m over an altitude change of 400 m) at a resolution of 1.5 cm. This pressure information can be combined with data from an external GPS receiver to achieve enhanced and faster position determination. The humidity sensor has a respectable response time of 1 s and communication with the chip occurs over the I2C and SPI (3-wire/4-wire) digital serial interfaces. In normal operation the chip cycles continuously between measurement and standby mode. The chip can also be configured to ‘forced operation’ where it remains in sleep mode until a measurement is requested.
Its low current consumption (3.6 μA @1Hz) and small size make it suitable for a wide range of mobile applications. [via]
The BME280, Three Sensors in One – [Link]
Raj @ embedded-lab.com writes:
A couple weeks ago I received some sample products from Dorji Applied Technologies, a china-based company that make varieties of RF and sensor modules. One of the products I received was their latest DSTH01 sensor module that carries Silicon Labs’ Si7005 digital relative humidity and temperature sensor on board. Things I liked about it are it is inexpensive (available on Tindie for only $6), compact, and most importantly it supports I2C host interface for communication.
Reviewing Dorji’s DSTH01 digital temperature and humidity sensor module – [Link]
Glyn Hudson over at OpenEnergyMonitor has developed this remote temperature and humidity monitoring node, the emonTH:
The emonTH supports both the DHT22 (humidity and temperature) and DS18B20 either onboard or remote temperature sensor. The default software will search for the presence of either sensor at startup. If both sensors are found it will return humidity from the DHT22 and temperature from the DS128B20. If only the DHT22 is found it will return both humidity and temperature readings from this sensor, finally if only the DS18B20 is found only temperature readings will be returned. In the future I would to expand the code to support multiple DS18B20 sensors on the one-wire bus.
emonTH – Wireless temperature and humidity monitoring node – [Link]
Electric Imp Solar Powered Temperature Logger
The first hack I did with the imp was a solar powered temperature logger using a TMP36 sensor and send the data to ThingSpeak
Electric Imp Solar Powered Temperature Logger – [Link]
Scott Harden writes:
In an effort to resume previous work [A, B, C, D] on developing a crystal oven for radio frequency transmitter / receiver stabilization purposes, the first step for me was to create a device to accurately measure and log temperature. I did this with common, cheap components, and the output is saved to the computer (over 1,000 readings a second). Briefly, I use a LM335 precision temperature sensor ($0.70 on mouser) which outputs voltage with respect to temperature.
Precision temperature measurement – [Link]
Make a WiFi Weather Station With Arduino and Adafruit’s CC3000 breakout.
As open-source hardware users and makers, we love playing with new chips, boards and tools. And there is one chip which is quite popular these days: the CC3000 WiFi chip from TI. This chip comes with many promises: cheap (around $10), easy to use, low-power … It was featured in many articles around the web, but somehow it was quite hard to use with Arduino as there was no breakout board or library available. Luckily, Adafruit solved that for us with a nice breakout board and a working library for Arduino. In this article, I will show you how to use this chip for home automation purposes. Remember that weather station project? We are going to do the same: measure the temperature and the humidity. But this time we won’t display the information on an LCD screen. Instead, we will transmit the data wirelessly via WiFi to your computer and display it there. Excited ? Let’s get started!
Make a WiFi Weather Station With Arduino and Adafruit’s CC3000 breakout – [Link]
Maxim’s Collection of temperature sensor and thermostat ICs
These temperature sensors offer good accuracy (±1.5°C) over the range of -25°C to +125°C and feature a 2-wire digital output with bus lockup protection and external reset.
Tushar @ embedds.com writes:
In this new tutorial, we will be interfacing a LM35 based temperature sensor with ATMEGA32. The 3 main types are thermometers, resistance temperature detectors, and thermocouples. All three of these sensors measure a physical property (i.e. volume of a liquid, current through a wire), which changes as a function of temperature. In addition to the 3 main types of temperature sensors, there are numerous other temperature sensors available for use.
Interfacing LM35 to ATMEGA32 – [Link]
Digital Temperature Sensor in TO-92 Package Ideal for Measuring Ambient Temperature.
The MAX31820 ambient temperature sensor provides 9-bit to 12-bit Celsius temperature measurements with ±0.5°C accuracy over a +10°C to +45°C temperature range. Over its entire -55°C to +125°C operating range, the device has ±2.0°C accuracy.
MAX31820 – 1-Wire Ambient Temperature Sensor – [Link]