Yes, we're talking about test jigs again this week on the factory. This time around, we've done a manufacturing run of the PiicoDev distance sensor. This is a laser distance sensor. We've done our production and now we need to test all of these distance sensors. Let's get started.

If you follow us on the socials, you might have seen this really, really nice slowed down footage of the laser distance sensor being assembled. Those are 0402 components being placed one by one, and if you look closely at the angle, you can even see how high the solder paste is on the pads. This was a really nice shot by our editor Luke.

I can see some room for optimization here. This resistor, which obviously is not directional, gets rotated 180-degrees, so that'll be something to fix. And you might see that there's a little bit of wobble in that strip. We actually have our panels in these strips rather than a grid, so we only have tabs on two or four sides, and that was a considered choice. There was a bit of weighing up there as to how we should panelize these. Each of these tabs we have to break off by hand, so it's far easier and faster if we only have two instead of four tabs. So we only have them on these sides and none on these sides, and you can see in that footage that there's a little bit of flex in the board, but it still manages to place 0402 components just fine.

So once we've depaneled down to a single board, we, of course, need to test them. This is one of the easier tests to do because a known distance is relatively easier to create than, for example, a known temperature or air pressure. So I retooled the PiicoDev test jig. This is the test jig that's been testing most of our PiicoDev modules.So far, I have created this laser-cut acrylic base for the PiicoDev test jig. It was really easy to create, just a couple of rectangles that I glued together using acrylic glue, and a couple of gussets to give it some strength. Initially, I considered bending it, but I wanted the distance to be quite accurate. I figured it would be easier to achieve an exact alignment of the edge rather than getting an exact bend with an exact radius in acrylic. In hindsight, I realize that I probably could have bent it because the tolerance on the laser distance sensor is within a few millimeters. So, bending it would have been fine.

When testing, I simply plug the module in, and we get a beep and a green light. Once I remove the device, the green light also disappears, allowing me to move on and test the next device. The purpose of this test is to measure the distance between the laser sensor and the target and ensure that it falls within the specified range.

You may be wondering why there are two connectors here. That's because this test jig is not only used for testing laser distance sensors. I have also used it with other sensors, where I connect a device under test in one socket and a reference device in the other. This allows me to compare the two.

The code for this test is quite simple. We start by initializing the sensor, then we take the average of 32 samples, as recommended by the data sheet. If the difference between the average and the reference distance (the real distance) is less than the tolerance specified in the data sheet, the test is considered a pass.

Considering all of this, it really amazes me how such a simple setup can provide accurate and reliable results.Time test, you know, you feel like you've just plugged the device on. The sample rate is just so high that in that time we're able to do 32 ranging measurements and then take the average. It just never ceases to amaze me.

You might recall I mentioned we'd have a go at an IMU or inertial measurement unit for PiicoDev. We've got the prototype designs in, we're just waiting for the PCB to arrive, got parts, even have a working code library already so this should be a nice fast one.

In any case, I've got to get back to testing these sensors because I hope to have them up on Core Electronics very soon. If you have any questions about anything you've seen today or if you have any suggestions, open a thread on the Core Electronics forums. We'd love to see you there.

Until next time, thanks for watching!