 The Great Search brought to you by Digikey and Adafruit. Every single week, Lady Adie is a power of engineering to help you. Yes, you find the things that you need on digikey.com. Lady Adie, what is The Great Search of the week? Just a good question. This week's Great Search is looking for a newer, better trim pot. I'm revising this design, the iSquirtz LCD backpack. Originally, I used the least expensive trim pot I could get, which was a perfectly fine trim pot. But let's look at how we can improve it. So let's go to the overhead and I'll show it off. So this is a board that connects onto an LCD and gives iSquirtz SPI interface. And I have to revision for this anyways. Ironically, not because the chips. The chips actually ended up coming back into stock, although the TSOP version is a little bit more available. So I might still change this up for a TSOP, depending on whether the SOIC versions appear magically on Digikey anytime soon. But I changed these two resistor packs and I changed these connectors. And then one of the things I really wanted to change was this little trimmer. So there's that contrast adjustment for character LCD displays. You usually only have to trim them for the first time you get them, depending on your temperature and voltage power supply. And I used these little mini metal trim pots. These are Born's TC33Xs, which are extremely common. And they're very inexpensive and they're very easy to pick in place and they're very reliable. Only thing is is that they're a little annoying. Like they're quite small and if you don't have exactly the right, you can't use Phillips, even though it looks like Phillips, you need to have a flat head. So it's a little confusing to people because they get the wrong screwdriver and then they get the flat head and it has to be exactly the right size flat head. It's kind of hard to tell what size it is. So I thought like maybe this would be a good opportunity if I'm gonna revise the board to maybe pick a slightly better trim pot. I want something durable about the same size. I have a little bit more space because I did shift around some parts. 10K trim pot, but I want it to be a little bit easier using the TC33X. So let's go to the computer. All right, so this is the board and again here is the trimmer. You see, I have a little bit of space, right? It doesn't have to be as small as it is here. So let's go to digit key and we will look for trim potentiometer. So the hardest part of this is to search the spelled potentiometer, right? Okay, so trimmer pots. Note that there's some wheel, there's kits and stuff, but we want trimmer pots. And a trim pots cup, again, you know, there's the through hole type. This is a through hole screw adjustable, multi-turn, all sorts of stuff, but usually they don't have a knob where that's kind of how I would differentiate the trimmer versus a non-trimmer pot. So first off, the resistance, I do need to have it be 10 kilo ohms. So might as well just, and it's the most common value, so let's just pick that off the top. Number of turns, only one turn. I don't need a high precision. You're gonna pay, you know, it's one turn and then like price goes up very high the moment you start doing multi-turns because it's mechanically more complicated. It has to be wire round instead of just having a sheet of resistant material. And of course I want to only search for active and then only surface mount because I want to be able to pick and place this component. So what's really nice is that, you can see most of these selections are already kind of coming into play and I only have 76 options to pick from, which is great. So if I search by, you know, just by price real simply, you will see the one that I use on the board right now the TC33X. Again, totally fine trim pot, lovely trim pot, love it, but it is a little bit challenging to use if it's the first time you've had to adjust a pot. It's good for engineers, not always very usable for beginners and makers or people who are not as agile or have a full scooter over set. But that said, these are very close. So let's also look for only ones that are normally stocking. And I don't want to look at marketplace. I'm just gonna look at what's available from Digikey. Thankfully, trim pots were not strongly affected by the chip shortage. So, you know, they do have a lot in stock. So there's a couple of good options. So, you know, this is getting a lot closer to what I want, right? It's still a surface mount trim pot and so it can go through the oven and everything but it has like a very clear slot. Like it's very clear like you need to use a flat head and you twist it and it's a little bit more compact. This is kind of open frame. It's a little bit like, whoa, what's going on? And there's a few. There's these ones also from Bornz, I think. Yeah, Bornz. These are like Phillips compatible. There's actually quite a few from Nidek and Bornz. You know, for my, you know, initial prototype, I ended up just going down with the 3314J because I happened to have some. But looking at it now, I'll tell you actually why I'm thinking of changing. So, this is kind of the most common trim pot, the 3314 series. But the thing about trim pots is that, you know, it's a mechanical, it's a mechanical interface much like, you know, it's a normal through-hole pot or terminal blocks. And you really do want, or USB ports, you want to have some mechanical strength because it's not going through the PCB. It's surface mount, so it can shear very easily. And so what I actually liked was, you know, I saw this one, but then this one I'm digging because, although they're both pretty good, this one goes underneath, but this one I really liked that it had like these legs that stick out and I can get like really nice, chunky surface mount pads. And I feel like that could give me a really good mechanical strength that'll protect against shearing when, you know, because somebody like they twist, they twist, they maybe they keep twisting a little bit too much, they could shear the pot off the PCB. So I actually ended up, and also another thing I like, it has 85,000 pieces in stock. Can't argue with that. So the Nidek Copal ST4ET series, this is my pick for the Great Search, this is what I'm gonna go spec into my board. It's also not too big. It's only five millimeters by five millimeters, which is well within reason for, you know, fitting on that PCB. Do watch out the scale. It's how it sometimes tell the scale. This can be, you know, six to 10 millimeters, but this one is a nice size. I think it's mechanically stable and I think it's really clear, use a flat head and it looks like it'll be very easy for people to use. And that's the Great Search.