# Big price reduction of Pololu MEMS sensor carriers and IMUs

Posted by Ben on 13 June 2014
Tags: pricing

We have some very exciting price reduction news to share with you, but first:

## A little background

MEMS (Micro-Electro-Mechanical Systems) devices are everywhere today, from airbag crash sensors to smartphones to inkjet printer heads, so it is easy to take this ubiquitous technology for granted without considering just how impressive it really is. The defining characteristic of a MEMS device is the presence of microscopic mechanical elements that are similar in size to the features of the electronics in an integrated circuit – if you look closely enough at the silicon of a MEMS inertial sensor, you will see tiny moving cantilevers or springs right alongside the electrical elements that let you interface with them.

Several of us here at Pololu fondly remember using our first MEMS sensors around the turn of the century (the “Y2K” one, not the horse-and-buggy one) as they became affordable enough to consider for our college engineering projects. At the time, it was around $20 for a single-axis accelerometer, and that seemed like a pretty sweet deal! Since then, widespread use of MEMS technology in mobile devices has led to rapidly improving performance and falling prices, putting some amazing technology well within the financial reach of students and hobbyists. However, these same market pressures favor compact, surface-mount ICs that can be integrated into ever-shrinking consumer products, making them very difficult to work with, and this is where we come in: our goal is to make these great sensors available to a much wider audience. We design and manufacture breadboard-compatible carrier boards for these MEMS ICs that include all of the additional required components along with voltage regulators and level-shifters that allow direct integration into 5V systems. One side effect of this rapidly evolving technology is that if we want our MEMS products to remain relevant, we have to update them more quickly than our other products. For instance, our 3pi is approaching six years old, yet it is still a decent basic robot platform (see my stock 3pi dominate our recent LVBots maze-solving competition). In that same time, we have gone from our first MEMS carriers – a 3-axis accelerometer for$20 and a single-axis gyroscope for $30 – to a complete IMU with 3-axis accelerometer, 3-axis magnetometer, 3-axis gyro, and pressure sensor, each with performance much better than those earlier units. So far, we have generally kept our prices the same or had modest decreases as we have released newer units with higher performance, but today we are announcing significant price cuts to our latest-generation boards: The LSM303D 3D compass and accelerometer carrier is now$9.95, down from $14.95. This inertial sensor consists of a 3-axis accelerometer and a 3-axis magnetometer in a single package. The L3GD20H 3-axis gyro carrier is now$12.95, down from $19.95. This inertial sensor measures the angular rates of rotation about the roll, pitch, and yaw axes. The MinIMU-9 v3 is now$19.95, down from $39.95. This IMU module features an LSM303D 3D accelerometer+magnetometer and L3GD20H 3D gyro, providing nine independent rotation, acceleration, and magnetic measurements that can be used to calculate the module’s absolute orientation. The AltIMU-10 v3 is now$27.95, down from $49.95. This IMU module is equivalent to a MinIMU-9 v3 with an integrated LPS331AP pressure sensor, providing ten independent pressure, rotation, acceleration, and magnetic measurements that can be used to calculate the module’s altitude and absolute orientation. This fast technology progression makes planning challenging – it sometimes takes six months or more from the time we order a newly-announced component to when it arrives, and by the time we get it and build a board around it, the next great part is announced. This leads to a somewhat complicated lineage of products in various life-cycle stages. The following diagram shows the progression of our products based on ST’s MEMS sensors, which we have been most excited about lately thanks to their digital interfaces and many user-configurable settings: The constant product refreshing also leaves us with older-generation boards that we generally put on clearance. We have decreased the clearance prices of these products so they remain compelling lower-price alternatives to the latest-generation boards. These boards are not recommended for new designs where continued availability is important, but if you just want to play around with a cheap sensor that was state-of-the-art a few years ago, these are a great deal while they last: The LSM303DLM 3D compass and accelerometer carrier has a new clearance price of$5.95.

The LSM303DLHC 3D compass and accelerometer carrier has a new clearance price of $7.95. The L3GD20 3-axis gyro carrier has a new clearance price of$9.95.

The MinIMU-9 v2 has a new clearance price of $14.95. This IMU module features an LSM303DLHC 3D accelerometer+magnetometer and L3GD20 3D gyro. The AltIMU-10 has a new clearance price of$22.95. This IMU module is equivalent to a MinIMU-9 v2 with an integrated LPS331AP pressure sensor.