Help Picking IMU

Projects General Guidance
1

Hello,

I am working on setting up a device for measuring accelerations inside protective packaging throughout a 50 foot drop. I am estimating that the impact time is going to take roughly 10ms and the accelerations will be well under 16 g's.

This may show how inexperienced I am, but my plan is to measure the accelerations with the an IMU, save all of the data on an SD card using an SD card module, then use MATLAB or Python for the post processing.

So far, I already have everything that comes in the Elegoo most complete starter kit (All the jumper wires and other small components that I will need) and I am looking to order the following: LSM6DS3 IMU, Micro SD Card Adapter Module, and an SD card.

First, I want to know whether it is worth it to upgrade to the Arduino DUE from the Arduino Mega 2560 that I already have due to the faster processing speeds and sampling rates.

Second, I am looking into the LSM6DS3 IMU due to its 16g range and 6.6 khz maximum sampling rate. Since I am fairly new to all of this I want to make sure that this IMU paired with the Arduino MEGA or Arduino DUE, still has the ability to sample at the 6.6 khz. I am also open to looking into other IMUs if there are any better ones for my application.

Price really isnt a concern, the issue is that I have limited time to complete the testing, and live in an area where online orders take a long time to receive.

Any advice would be greatly appreciated.

2

Modern processors are blindingly fast. You could probably use a NANO with no trouble.
You say

has the ability to sample at the 6.6 khz

The NANO is a 16Mhz MCU.
Do the math.

3

Does the first, basic kit work?

4

If this is "free fall", the measured acceleration will be zero, until it hits the bottom.

5

Yes, I should have phrased that better. I am more concerned about the impact than the actual fall.

6

To measure impact acceleration, an accelerometer with sufficient measurement range is required. For example, the ADXL377 has range +/- 200 g.

The MCU must have a fast ADC as well.

7

I am estimating with some rough calculations that my max acceleration should be round 3 or 4 g's so im not too worried about the range. I am more so looking for making sure that nothing is bottle necking my sampling rate and causing the device to miss the max acceleration.

Do you have any ideas on specific IMUs to use?

8

Check the data sheets to see if the device meets or exceeds the required sample rate. Forum members can't help if you don't provide the numbers.

The sensor bandwidth may be a limitation.

9

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