by Jordan Dimitrov @ edn.com:
While most carbon dioxide sensors use IR technology, electrochemical sensors are a serious competitor because of their high sensitivity, wide measurement range, and low price. As a rule, electrochemical sensors connect to a microcontroller through a buffer amplifier with an extremely low bias current (<1pA). The micro is needed to linearize the logarithmic response of the sensor. A good example of this approach is the SEN-000007 module from Sandbox Electronics, which uses an MG-811 CO2 sensor from Hanwei Electronics. Reference 1 reveals the circuits and the code, but does not specify accuracy.
Antilog converter linearizes carbon dioxide sensor - [Link]
Ioannis Kedros writes:
It’s been a long time since I’ve post a new hobby project of mine! I decided that is time to upload a new one! Like my Sensor Stick module this project will be about sensors as well.
You can find multiple modules out there with various sensing ICs that almost all of them look exactly the same! They are ugly and without properly markings on their surface.
For example, some of those don’t have the input voltage range on the PCB or the pin out names or even the sensor address (in the case of a digital I2C sensors for example). In order to find that info, you have to download files, unzip them, look the schematics of the module then the datasheet of the sensor etc. A time consuming method especially for a quick and dirty prototype!
embeddedday.com – Sensor Modules - [Link]
Davide Gironi writes:
A Spark.io library for the BH1750FVI IC.
The BH1750 IC is a light intensity sensor module with built-in a 16 bit AD converter generating digital signal. With the BH1750 Light Sensor intensity can be directly measured by the luxmeter, without needing to make calculations. This library provides function to measure lux through I2C on a Spark Core.
Measure brightness in Lux using BH1750 sensor on Spark core - [Link]
by fileark @ electronhacks.com:
BMO from Comedy Central’s Adventure Time is adorable, if only someone would make one that can walk! Atleast we can make one with a personality. Here is a build using easy to get parts including Arduino Pro Mini, Nokia 3310 LCD screen, audio playback, accelerometers, and distance sensors.
The parts added up to around $70.00
DIY Arduino Mini BMO - [Link]
Cambridge Sensors Ltd have announced the appointment of the ASE group to assemble and test there latest tiny (currently the world’s smallest) gas sensor. The 2.0mm x 3.0mm cavity DFN package developed together with ASE enables the integration of gas sensors into devices such as smartphones, tablets and wearable devices where it has previously not been physically possible.
The CCS800 product family of ultra-low power miniature gas sensors can be used for detecting Ethanol (Alcohol) and hazardous gases such as Carbon Monoxide (CO) and a wide range of Volatile Organic Compounds (VOCs) including Formaldehyde. According to Fuyu Shih the vice president of ASE Europe: “The Global emergence of sophisticated electronics geared towards improving lifestyle and efficiency is fuelling the sensor market, making it one of the fastest growing areas of innovation within the semiconductor industry”.
Smartphone Nose - [Link]
Project is based on Holteks IC HT7610A, which is a CMOS LSI chip designed for use in automatic PIR lamp, flash or buzzer control. It can operate in 3-wire configuration for relay applications. In our project we have used relay instead of Traic to connect any kind of load in output, HT7610B IC is suitable for traic and HT7610A for Relay application. The chip is equipped with operational amplifiers, a comparator, timer, a zero crossing detector, control circuit, a voltage regulator, a system oscillator, and an output timing oscillator.
Its PIR sensor detects infrared power variations induced by the motion of a human body and transforms it to a voltage variation. If the PIR output voltage variation conforms to the criteria (refer to the functional description), the lamp is turned on with an adjustable duration. The circuit doesnt required step down transformer and can work directly by applying 110V AC or 220V AC (Capacitor C7 needs to change for 220V AC (0.33uF/275V) and 110V AC (0.68uF/275V)
PIR Sensor - [Link]
An all-in-one, water and sand resistant, solar charger, audio speaker system, and sunburn timer calculator by starwisher. Check out the project’s instructables page here:
This Instructable harnesses the power of Arduino, a UV sensor, and simple mathematics to make one nifty gadget sure to boost your outdoor summer fun – and minimize your indoor summer recovery!
Beach Buddy, a 3-in-1 solar phone charger, boombox, and sunburn timer calculator - [Link]
A new type of sensor being developed by a team of researchers at the University of California, Berkeley based on Plasmon laser technology is so sensitive it may be able to detect the presence of land mines in situ. In a paper published recently in the journal ‘Nature Nanotechnology’ a team of researchers led by Xiang Zhang, UC Berkeley professor of mechanical engineering, have outlined how they have been able to find a way to increase the sensitivity of a light-based plasmon sensor to detect minute concentrations of explosives. The new sensor consists of a layer of magnesium fluoride sandwiched between a semiconducting layer of cadmium sulfide, and a sheet of silver.
New Sensor could sniff out Land Mines - [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]