‘No-Parts’ temperature measurement with Arduino Pro Mini

From the comments on our ESP8266 temperature logger post, Edward Mallon  writes: The ESP8266 has a hardware watchdog timer, so you could probably use that to measure temperature to much better resolution that you’d get from a DS18B20. We get better than 0.003C using the technique with cheap Pro Mini Clones Ooops, I missed an important […]

App note: Calibration of the AVR’s internal temperature reference

Another app note from Atmel, calibration of the AVR’s internal temperature reference (PDF!) This application note describes how to calibrate and compensate the temperature measurements from the ATtiny25/45/85. It can also be used on other AVR® microcontrollers with internal temperature sensors. The temperature measurement is based on an on-chip temperature sensor that is coupled to a single […]

Temperature and humidity measurement with DHT11

  Ondrej Karas of DoItWireless writes: This article describes temperature and humidity measurement with DHT11 sensor connected to TR module. Circuit diagram is very simple. You need only power supply for sensor and one wire for data line. This line has to be “pull-uped” – sensor has open colector output.

Temperature compensation for an Arduino ultrasonic distance sensor

Sverre Holm writes: Ultrasonic distance sensors can find the range out to 2-4 meters and are popular in e.g. robotics. Here I look at how the accuracy can be improved by compensating for the variation of speed of sound with temperature. It actually varies quite a lot in air and around 0 C it is: […]

DIY digital desk clock with temperature display -part 1

A digital desk clock with temperature display feature by Electro-Labs: The brain of the circuit is a Microchip PIC18F252 microcontroller. It acquires precise time information from DS1307 real time clock via I2C interface and displays it on four digit 38 mm seven-segment display with the help of MAX7219CNG display driver. The temperature data is read […]

Open source data logger for biodiversity research

Ed Baker of the Natural History Museum, London, UK, has published a paper outlining his build of an open source hardware data logger for scientific purposes. “Proprietary data loggers can be expensive – for example a three channel data logging system is available from Alphatemp for £465.00. Such costs make large scale deployment of such […]

OctoPROBER rev0 board update

Parker Dillmann posted an update on his OctoPROBER board  an 8 channel K-type thermocouple temperature logger, we wrote about it previously: I was having an issue with the FT230X being active while the 3.3V rails being turned off. The FT230X would backfeed voltage down the TXRX lines into the propeller which would power the 3.3V rail to ~2.7V causing […]

OctoPROBER, The 8-Channel temperature logger

Parker Dillmann of Longhorn Engineer is working on a 8 channel K-type thermocouple temperature logger, the OctoPROBER: This has been an idea I have been kicking around for awhile. The OctoPROBER is a 8 channel, K-type thermocouple temperature logger. It has a micro SD card slot for logging data remotely. The USB connection can send log data […]

App note: Temperature measurement using thermistors

Another temperature sensitive device, introducing the thermistor. From its name you could guess that its a temperature dependent resistor which varies its resistance as the temperature changes. See Cypress’ application note on using these devices. A thermistor is a temperature-sensitive resistor in which resistance varies with temperature. There are two types of thermistors: positive temperature […]

App note: Temperature sensing using diode

Last time we covered using watchdog timer as temperature dependent component of a microcontroller to do temperature sensing. Now lets take a diode to do the same thing, they are pretty much accurate and cheap, see Cypress’ application note about its implementation. There are various sensors available for measuring temperature such as Thermistor, Thermocouple, resistance […]

emonTH – Wireless temperature and humidity monitoring node

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 […]

PIC16F74 – room thermostat with colour LCD

Room thermostat with PIC16F74, DS1820, and the Siemens M55 color LCD: The heart of the unit is an 8 bit PIC16F74 microcontroller from Microchip. It’s main task is to constantly monitor the room temperature trough a 1–wire digital thermometer IC, a DS1820 from Maxim, and to switch a relay on or off, that controls the […]

AVR based intelligent temperature monitoring and control system

Shawon designed, and built an AVR based intelligent temperature monitoring and control system. He documented both the hardware, and the firmware on his blog, with in depth descriptions on how everything works. Controlling temperature has been a prime objective in various applications including refrigerators, air conditioners, air coolers, heaters, industrial temperature conditioning and so on. Temperature […]

Interfacing a DHT11 humidity and temperature sensor

Raj show how to interface his PIC16F breakout board with the DHT11 humidity and temperature sensors. The DHT11 uses a proprietary single-wire protocol, not Maxim’s 1-Wire (which we consider EOL). This articles discusses the DHT11 sensor which also provides calibrated digital outputs for temperature and humidity but is relatively lot cheaper than the Sensirion sensors. […]

RS-485 temperature sensor source files uploaded

As a follow up to his RS-485 temperature sensor board, Ezflyer added PCB and schematic files: I’ve been meaning to post the Eagle schematic and board files for this project for a while now, but never got around to it. An email from a forum member (thanks Karel!) interested in this project prompted me to […]