![\"Accelerometers:](\"https:\/\/blog.seeedstudio.com\/wp-content\/uploads\/2020\/11\/Accelerometers_-1030x579.png\")
<\/figure><\/div>\n\n\n\nBefore we get onto our main dish, let’s recap a few concepts that would help you understand accelerometers better:<\/p>\n\n\n\n
- I2C<\/a>: Also known as Inter-Integrated Communication, it is a popular serial communication protocol, a two-wire data transfer bus.<\/li>
- SPI<\/a>: Also known as Serial Peripheral Interface, it is a synchronous serial data protocol that acts as an interface bus.<\/li>
- ADC<\/a>: Also known as Analog-to-Digital Converters, they basically convert an analog input into a digital input.<\/li><\/ul>\n\n\n\n
Should you have any doubts about these concepts, do click on the links to read these articles in depth!<\/p>\n\n\n\n
<\/div>\n\n\n\nPutting that aside, let’s look at what will be covered in this article:<\/h4>\n\n\n\n
- Overview of Accelerometers<\/li>
- Formulas and calculations<\/li>
- Recommendations<\/li>
- Applications<\/li>
- Projects<\/li>
- Related products<\/li><\/ul>\n\n\n\n
\n\n\n\nOverview of Accelerometers<\/h2>\n\n\n\n
What is an Accelerometer?<\/h3>\n\n\n\n
Accelerometers are electromechanical devices that measure acceleration<\/em>, the rate of change in velocity of an object. Simply put, it is a device used to respond to any vibrations associated with movement.<\/p>\n\n\n\n
![\"\"](\"https:\/\/static-cdn.seeedstudio.com\/media\/catalog\/product\/cache\/9d0ce51a71ce6a79dfa2a98d65a0f0bd\/h\/t\/httpsstatics3.seeedstudio.comseeedfile2018-07bazaar881168_1.jpg\")
<\/figure><\/div>\n\n\n\n<\/div>\n\n\n\nHow does an Accelerometer work?<\/h3>\n\n\n\n
In order to understand how an accelerometer works, you need to know what goes into an accelerometer. Here’s a simple diagram to help you with that, here we’re using the commonly used piezoelectric accelerometer as an example:<\/p>\n\n\n\n
![\"\"\/](\"https:\/\/www.instrumentationtoday.com\/wp-content\/uploads\/2011\/08\/Piezoelectric-Accelerometer.jpg\")
Ref: instrumentationtoday<\/a><\/figcaption><\/figure><\/div>\n\n\n\n As its name suggests, a piezoelectric accelerometer uses a piezoelectric natural quartz crystal or lead zirconate titanate (PZT) which could be referred to as the piezoelectric effect.<\/em> When an accelerative force is applied upon it, the crystal will produce a voltage that is proportional to the accelerative force. The force will then be measured.<\/p>\n\n\n\n
<\/div>\n\n\n\nTo give a simple example, the image below is a 3-axis MPU9250 accelerometer sensor<\/strong>. If you were to leave it flat on the ground with Z-axis facing up, Z-axis output of sensor = 1 g or 9.8m\/s^2 while X and Y = 0. This is because there is no other force acting upon the X and Y-axis, the gravitational force does not affect them.<\/p>\n\n\n\n
Note: With “g” referring to the gravitational force and m\/s^2 as the unit of measurement for acceleration (we will go in-depth in the latter part). <\/p>\n\n\n\n
![\"\"](\"https:\/\/blog.seeedstudio.com\/wp-content\/uploads\/2020\/06\/image-55.png\")
<\/figure><\/div>\n\n\n\nIf you’re interested to learn the working of an accelerometer in-depth, do check out Instrumentation Today’s page<\/a> on how a natural quartz crystal is cut and used in replacement of lead zirconate titanate (PZT).<\/p>\n\n\n\n
\n\n\n\nVariations of Accelerometer<\/h2>\n\n\n\n
We did briefly mention about Piezoelectric accelerometer earlier, but do you know that there are many other accelerometers? Though we will only focus on the few common ones. Let’s take a closer look at each of them!<\/p>\n\n\n\n
<\/div>\n\n\n\nPiezoelectric Accelerometer<\/h3>\n\n\n\n
As we know the name of this accelerometer comes from the Piezoelectric quartz crystal, but a common piezoelectric accelerometer uses lead zirconate titanate (PZT). This sensing element would produce a proportional electric charge or output under acceleration, and it measures vibration<\/strong>.<\/p>\n\n\n\n
![\"\"](\"https:\/\/www.pcb.com\/contentstore\/mktgcontent\/webimages\/resources\/techsupport\/ICP-accel1.jpg\")
Ref: PCB Piezotronics<\/a><\/figcaption><\/figure><\/div>\n\n\n\n The Piezoelectric accelerometers are often used for test and measurement purposes. What’s great about them is that they’re easy to install, provides a wide frequency response as well as high sensitivity. Thus, making them a popular choice for vibration testing!<\/p>\n\n\n\n
<\/div>\n\n\n\nPiezoresistive Accelerometer<\/h3>\n\n\n\n
Though Piezoresistive accelerometer may sound similar to the Piezoelectric accelerometer, not to be mistaken, they are pretty different! <\/p>\n\n\n\n
How a Piezoresistive accelerometer works are pretty alike to a strain gauge, it measures stress<\/strong>. It is made with a Piezoresistive material and it’ll be deformed after a force is applied to it where the change in resistance is measured. <\/p>\n\n\n\n
Ref: openPR<\/a><\/figcaption><\/figure><\/div>\n\n\n\n Piezoresistive accelerometer’s high bandwidth allows it to measure high frequency in short duration, which makes it perfect for crash or weapons testing. Though it is not as helpful for vibration testing due to its low sensitivity.<\/p>\n\n\n\n
<\/div>\n\n\n\nCapacitive MEMS Accelerometer<\/h3>\n\n\n\n
Do you know that MEMs stands for Micro-Electro-Mechanical Systems? So they’re technically a technology for manufacturing accelerometers. MEMS itself isn’t an accelerometer, but it is used to manufacture both Capacitive <\/em>and Piezoresistive<\/em> accelerometers! Unlike the other two accelerometers we mentioned, it measures the capacitance changes in the seismic mass under acceleration.<\/p>\n\n\n\n
- SPI<\/a>: Also known as Serial Peripheral Interface, it is a synchronous serial data protocol that acts as an interface bus.<\/li>
![\"\"\/](\"https:\/\/ars.els-cdn.com\/content\/image\/1-s2.0-S1386276600800158-gr10.gif\")
![\"\"](\"https:\/\/www.dummies.com\/wp-content\/uploads\/acceleration-formula.png\")
<\/figure>\n\n\n\n