by BrittLiv @ instructables.com:
Heating things up is one of the most performed tasks in a lab. Quite a lot of times it is not enough to simply hold something at a certain temperature, but the rate at which something is heated and for how long is just as important. Especially when you try to develop catalysts for chemical processes, the temperature program and exact temperature control is crucial and you probably do not want to stay in the lab for 16 hours to manually adapt your temperature program. Unfortunately, programmable temperature controllers that can automate processes are really expensive. So I decided to build a highly customizable controller that is able to run temperature ramps and read multiple different temperature programs from a SD card. It also provides a logging function on the SD card that allows you to evaluate the resulting temperature profile after running a program.
Programmable Temperature Controller + Hot Plate - [Link]
This DIY digital clock plus thermometer is designed by Joe Farr and is based on PIC18F25K22 microcontroller. The complete construction details of this project including circuit diagrams, PCB layouts and PIC firmware are posted in his website. He developed his firmware using Proton PIC BASIC compiler, which is available for download for free for this particular PIC microcontroller. He uses DS1302 RTC for timekeeping and DS18B20 for temperature measurement. The temperature and time are displayed on four 2″ seven segment LED displays.
Another PIC-based digital thermometer and clock - [Link]
A simple temperature control system for 3D print or other constant temperature control purpose by Xiang:
I plan to build a home-made 3D printer controlled by my Raspberry Pi, which, unfortunately, does not have any analog data acquisition pin. Therefore I decide to build a stand-alone temperature control system.
The idea is very simple. I use a power resistor as the heater and a thermistor as the temperature sensor. The system contains an LM324 quad op-amps chip. One op-amp is used as a comparator to compare the thermistor resistance with a nominal resistance and output LOW or HIGH as the comparison result. The other three op-amps inside the LM324 are used to perform some linear transformation and output a voltage that is proportional to the thermistor temperature. This voltage is applied to a 0-30V voltmeter so one can read the temperature. A N-Channel MOSFET transistor is used to control on/off of the heater.
Simple temperature control system - [Link]
We have already seen a number of ideas for tracking tags seeking funds on Kickstarter, most systems are limited by the range of Bluetooth communication with a smart device. This system from Iotera tackles the problem using cloud-based thinking: The basic wireless system consists of one or more tags or ‘iotas’ and a home base unit. Each 22 x 11 x 3 mm iota contains a chip, accelerometer, temperature sensor, speaker, RF transceiver, Bluetooth (unused so far) and a battery to give up to three months operation. Each iota communicates with the home base unit using wireless channels in the 902 to 928 MHz band giving a range of up to four-miles. Back home, the base unit receives the low-speed transmissions from the iota tag and forwards the information to a server via a Wi-Fi connection.
Novel Cloud-based Tag System - [Link]
by dzzie @ github.com
The Dht22 sensor is installed in the humidor.
The arduino takes a reading every 20 minutes, and uploads the data to your webserver.
The PHP script will record the data to the database. If the temp or humidity is out of desired range, it will send you an email alert.
Alerts must be manually cleared latter by logging into the web site, so you are not spammed, before you get a chance to fix it.
When you add water, push the select button on the LCD sheild to record it. This will be saved to the db as well. Power resets will also be recorded to the database.
See screen shot for example web report.
Temperature controlled humidor with web logging, monitoring and alerts - [Link]
Miniature calibrated humidity and temperature sensor Sensirion SHTC1 is usable even in space – limited applications.
Really miniature dimensions and a low price are main benefits of new calibrated sensors SHTC1 from production of company Sensirion. If you ever tried well known sensors series SHT2x, probably you´ve been surprised by their small dimensions (3,2×3,2x2mm). However the new sensor SHTC1 shifts dimensions a level further, or better said – lower. The result is a DFN package with dimensions of only 2x2x0.75mm, what in praxis represents a package, which you may not notice at a cursory look at a populated PCB. That´s why the SHTC1 is primarily intended for mobile applications and everywhere, where a spared space and a minimal power consumption are beneficial.
Taking a low price in mind, the guaranteed accuracy of SHTC1 chip is relatively excellent, roughly on a level of SHT21. Typical accuracy of ±3% in a range of 20-80% RH and ±0.3°C is probably fully sufficient for majority of applications. 1.8 V supply voltage and ultra low power consumption below 1uJ/measurement are ideal for battery powered devices. SHTC1 supports I2C fast mode (0-400 kHz). This small package practically can´t be soldered by hand, but it is relatively easily possible by means of a solder paste and a hot-air soldering station.
Also the SHTC1 is produced by a well proven CMOSens technology, which proves its reliability and a long-term stability in industry. Similarly, the SHTC1 also isn´t only a “sensor” but a ready-made calibrated solution containing 2x sensor, low-noise amplifier, A/D interface, data processing unit with calibration data in a ROM and a communication interface. Detailed information can be found in the Sensirion SHTC1 datasheet and the Sensirion Humidity flyer.
We´ve got samples ready for you!
If you´re interested in trying this perspective sensor, take part in a contest below the article, or contact us on a well known address email@example.com.
SHTC1 we keep so far as an item upon order, but we´re able to supply it to you in a short leadtime and soon it will be a standard stock item.
SHTC1 – humidity and temperature from a pin head - [Link]
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 collector output.
Temperature and humidity measurement with DHT11 - [Link]
TMP75B 1.8-V Digital Temperature Sensor with Two-Wire Interface and Alert. by ti.com:
The TMP75B is an integrated digital temperature sensor with a 12-bit analog-to-digital converter (ADC) that can operate at a 1.8-V supply, and is pin and register compatible with the industry-standard LM75 and TMP75. This device is available in an SOIC-8 package and requires no external components to sense the temperature. The TMP75B is capable of reading temperatures with a resolution of 0.0625°C and is specified over a temperature range of –55°C to +125°C.
The TMP75B features SMBus and two-wire interface compatibility, and allows up to eight devices on the same bus with the SMBus overtemperature alert function. The programmable temperature limits and the ALERT pin allow the sensor to operate as a stand-alone thermostat, or an overtemperature alarm for power throttling or system shutdown.
TMP75B – 1.8V Capable Digital Temperature Sensor - [Link]
Build temperature & humidity & smoke alarm system based on ICStation Mega 2560 compatible with Arduino( Cost is USD32.39 ONLY) .
The working voltage of this system is DC5V.It can measure the current temperature, humidity and smoke. It can display real-time data by the 1602 LCD and can realize the sound and light alarm when in the dangerous temperature and humidity. It is a simply and easily to operate monitoring alarm system about temperature humidity and smoke.
Build Temperature & Humidity & Smoke Detector Alarm System Based on Arduino - [Link]
I recently stumbled across an interesting fact in the datasheet for the ATMEGA32u4, the microcontroller I am using for my Einstepper Project. I was surprised to find that Atmel had included a temperature sensor in the core of the device that you can read using the internal ADC. As it turns out, there are many megaAVR devices contain an internal temperature sensor. According to Atmel’s product finder, these devices are:
ATMEGA Core Temperature Sensor - [Link]