According to a press release from the ALPS Electric Co their HSHCAL humidity sensor is currently the world’s smallest commercially available digital humidity sensor. Preliminary information released by ALPS on the chip shows a 2 x 2 x 1mm package with six contact pads. [via]
The sensing mechanism uses changes in capacitance to measure relative humidity in the range from 0 to 100 %. Humidity readings are output as a digital value with a 14-bit resolution and a quoted accuracy of ±1.5 % RH at 25 ºC, 50 % RH. An internal temperature measurement feature outputs temperature information which is also used internally to compensate for the temperature coefficient of the humidity sensing element and improve linearity. The HSHCAL sensor operates from 1.71 to 1.89 V and draws 15 µA operating at 1.8 V and 1 Hz.
The company anticipate that the device will principally find a home in mobile devices such as Smartphones, wearable electronics and also in air-conditioning, air purification and refrigeration applications. The device is now in full production.
A Tiny Digital Humidity Sensor - [Link]
by Kalle Hyvönen:
I saw a cool app-note from Maxim that described a gamma-photon detector which used a regular PIN-diode as a sensor. The actual circuit looked simple enough so I decided build it, you can never have too many measurement instruments right?
The detector in itself is pretty simple, just some op-amps and a comparator. I decided to build it with all the bells and whistles so I included a digital potentiometer so you can adjust the reference voltage to the comparator via an SPI-bus. I also used a 5V reference shunt as the reference for the op-amps and the comparator to keep the circuits behaviour more consistent. I didn’t have any adjustable capacitors with an SPI bus so I decided against using one (instead of C4, changing the capacitance changes the gain).
A radiation detector with a solid-state PIN-diode sensor - [Link]
Allegro MicroSystems have announced the release of its ATS605 range of rotation sensors. This device provides a single chip solution to rotational position sensing of a ferrous gear target. Using three integrated Hall sensors together with Hall interface amplifiers, AGC stage, A/D converter and a synchronous digital controller, the ATS605 is able to accurately resolve the movement of much smaller-toothed cogs than was possible with previous revolution detector solutions.
Signals from the three Hall sensors are routed to two independent differential channels where digital processing with Automatic gain control helps compensate for magnetic variation and system offsets. The open-drain outputs provide voltage output signals which mirror the sensed target’s shape, with a phase separation between the two channels proportionate to the size of the target teeth vs. the Hall element spacing. These produce a highly accurate speed output and can also provide direction of travel information. Devices with an ‘H’ suffix have a maximum operational frequency of 40 kHz. [via]
Single Chip Rotation Sensor - [Link]
Ioannis Kedros writes:
I just finish the assembly process of my latest super mini project! It’s nothing amazing… but its a very handy sensor module!
On board there are three commonly used sensors: SHT10, BMP085 and MPU6050. I was constantly using those ones over my last projects and I thought it will be a good idea to make a simple module with all of those. They are communicating over I2C and the module can accept voltages from 3V to 6V.
Sensor Stick - [Link]
Here’s a simple cure for your posture and the back pain blues, a posture sensor by Wingman:
The simplest distance sensors are ultrasonic or infrared sensors. I went with a SR-HC04 because it is cheap and sufficiently precise. There are no special requirements to the controller so I am using an Attiny85. A small piezo speaker provides acoustic feedback to the user. The only thing left is the power supply for which 5V are needed because of the ultrasonic sensor. You could easily use an USB port but I did not want to rely on a computer, 3 button cells deliver around 4,5V and should work for a few days.
A simple posture sensor - [Link]
Complete digital temperature sensor Sensirion STS21 provides a top-level accuracy and stability for a very affordable price.
Digital sensor STS21 s the newest member of calibrated humidity and temperature sensors family SHT2x (SHT21, SHT25). In opposite to them, STS21 is able to measure only temperature, i.e. it´s suitable only for applications, where we don´t need to measure humidity. However a smaller functionality has also a significant positive aspect in a form of a substantially lower price. STS21 contains on a chip, similarly like its familiar, a temperature sensor, precise supply, low noise linear amplifier, AD converter and a serial interface with I2C output (fixed address different from SHT series).
Basic accuracy of STS21 in the 0 to +60°C temperature range is +-0.2°C. The user can choose a resolution for measuring and it can be 11-14 bits (up to 0,01°C). Despite the fact, that the sensor hasn´t guaranteed absolute accuracy of 0.01°C, such a high resolution can be beneficial for example for monitoring of a tendency (increasing/ decreasing) of temperature.
Detailed information can be found in the Sensirion STS21 datasheet.
STS21 measures temperature with an 0.01 °C resolution - [Link]
Low Voltage Metal Sensor directly compatible with Arduino type computers for Robotics, Hobbyists, & Engineers without using magnets.
The Low Power Non Magnetic Inductive Proximity Sensor is a Great way for Engineers, Makers, and DIYs to easily detect low permeability (non iron) metals such as aluminum. Why aluminum? Aluminum is widely available, inexpensive, very thin, and easy to apply. With a small piece of aluminum attached by tape or glue to almost anything, it can be detected by this Low Power Non Magnetic Inductive Proximity Sensor. Other low permeability metals such as copper can also be easily detected. This sensor is not to be confused with low cost magnetic sensors which obviously need magnets to operate.
Low Voltage Metal Sensor for use with Arduino type board - [Link]
This guide is intended to everyone interested in in using Accelerometers and Gyroscopes as well as combination IMU devices (Inertial Measurement Unit) in their electronics projects
- What does an accelerometer measure?
- What does a gyroscope (aka gyro) measure?
- How to convert analog-to-digital (ADC) readings that you get from these sensor to physical units (those would be g for accelerometer, deg/s for gyroscope)
- How to combine accelerometer and gyroscope readings in order to obtain accurate information about the inclination of your device relative to the ground plane
Accelerometer & Gyro Tutorial - [Link]
What’s inside a Dräger Multiwarn II gas detection warning system used in mining, oil, chemical, and emergency services etc to detect hazardous or explosive atmospheres.
Intrinsic safety design and how both catalytic bead and infrared IR gas detectors work, and pellistors. And a teardown of a Hydrogen Sulfide (H2S) sensor.
EEVblog #603 – Gas Sensor Teardown – Dräger Multiwarn II - [Link]
The MAX31730 temperature sensor monitors its own temperature and the temperatures of three external diode-connected transistors. The operating supply voltage is from 3.0V to 3.6V. Resistance cancellation compensates for high series resistance in circuit-board traces and the external thermal diode, while beta compensation corrects for temperature-measurement errors due to low-beta sensing transistors.
MAX31730 – 3-Channel Remote Temperature Sensor - [Link]