♪ One fine wire ♪
I²C Smart Sensors use a two-wire serial interface
and allow ultraminiature sensors and low pin-count microcontrollers.
This I²C magnetometer measures magnetic field
and is linear to a millitesla.
And this I²C Angle Sensor precisely measures the rotation of a magnet.
I²C has just a clock--SCL, and a bidirectional data line--SDA.
SPI is also popular for sensors
and doesn't need Slave addresses.
but it's a four-wire bus,
and needs a chip select for each Slave,
which can take a lot of microcontroller outputs
with a lot of sensors.
The demonstration uses a Trinket board with a 50-cent, eight-pin
ATtiny microcontroller as an I²C Master.
The two Smart Sensors and the I²C display
are all connected by just four wires: two for I²C plus power and ground.
So we could do this with a 25-cent
six-pin microcontroller and still have a couple of extra pins.
Our Smart Sensors have a pin to change the I²C address,
which we used on one of the sensors.
I²C addresses are programmable if we need more than two sensors.
With just two wires for the interface, there are also enough pins
for a digital threshold output on a 6-pin magnetometer.
Here's the code to read and display a basic SM124
one-byte, eight-bit magnetometer.
And here's the code for an ASR012 two-byte angle sensor.
The program for the demo was more general with arrays to define sensor properties.
It reads the sensors via I²C,
determines if a sensor is active,
and displays the active sensor's output
in millitesla for the magnetometer, or degrees for the angle sensor.
We used an inexpensive Trinket and TinyWire I²C library,
but you can do this with any Arduino-type board.
NVE Smart Sensors include a GMR or TMR sensor element,
Digital Signal Processing,
and an I²C or SPI interface controller.
So we've seen that NVE Smart Sensors are ridiculously simple to connect.
They are also: factory calibrated;
full temperature;
temperature compensated;
high speed;
and ultraminiature.
SM-Series Smart Magnetometer specs include:
accuracy;
repeatability;
and sensitivity.
ASR-Series Smart Angle Sensor specs include:
0.1 degree precision;
0.2 degree repeatability;
and wide magnetic field operating range.
We have a full line of I²C Smart Sensors...
SPI Smart Sensors...
and raw sensor elements with analog outputs....
Raw sensors are compatible with analog circuitry;
they have large outputs,
ultralow power,
inexpensive,
and some are barely a millimeter square.
Applications for these smart and raw sensors include:
proximity sensing;
noncontact current sensing;
angle and rotation sensing;
and robotics.
Call, click, or e-mail us for more information,
or to buy sensors, breakout boards, or evaluation kits.