Tag: electronics

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Solder Board

I created what I am calling a “Solder Board” which is like a breadboard but with no internal connectors. The solder board is used for… soldering! Specifically, for soldering pins onto PCBs, and in this case, onto microcontrollers. But first, some history…

For years I’ve soldered pins onto PCBs by jamming header pins into whatever breadboard was lying around and then slapping the PCB onto the pins, soldering the pins on, and then prying the board off. It works… mostly.

A year or two ago I had to solder a lot of Teensy boards, and finally found a use for those tiny breadboard. I taped off the edges to mark the size of the board and then taped it onto a chuck of Aluminum I had lying around for some extra weight and height.

And it worked pretty well. I would stick the pins in the outer columns (which I sized using my Header Pin Snapper tool) and be ready to go.

Drop the board on top, get to soldering, and then pry it off. Was it the best thing? No. Was it better than other methods? Yes. Could it be improved? Probably.

Since I now solder a lot more Raspberry Pi Pico boards, the little Teensy jig was too small, so I started using a larger breadboard, which presented a few problems. The first is that unless you have an old and somewhat “worn out” breadboard, inserting the pins can be a bit difficult. Often it took a lot of pressure to get them inserted. Sometimes one or more would pop up and be uneven with the rest. After that you need to solder them and remove the board, which can take quite a bit of prying if it’s in there tight. None of this is super difficult, but it’s a pain point, and we don’t need to deal with it.

Also, the Raspberry Pi Pico boards are 20 pins long instead of 14 like the Teensy, so more pins makes it just a bit more difficult to put the pins in and remove the board after soldering.

So above you’ll see the solution. A 3D printed “Solder Board” which was specifically designed for soldering header pins in place. (Unlike a typical breadboard.)

Put the header pins in place… no hard pressing required! The holes are sized such that they just drop right in.

Solder those pins and the board lifts right out. No prying! No pulling. Heck, you can probably flip it over and the board will fall right out.

Here’s the 3D model. Pretty simple. It’s a block with some holes. This one is sized specifically for the Raspberry Pi Pico board. You can’t really put the pins in the wrong place, which means you can work faster with less guesswork and chance of screwing up.

But maybe you want more holes… Just set the “useMoreHoles” option to get all the holes. This might be handy if you just want a general purpose Solder Board, and not one specific to one board size.

Wait, you want even more holes!? You can make one any size, thanks to the magic of parametric design in OpenSCAD.

I’ve tried to add just a few parameters to the OpenSCAD file to allow for customizing it without going overboard. The number of rows and columns, the padding (part without holes) on the sides and top/bottom, the height, and even hole diameter, to adjust for (ahem) printers that are not quite dialed in very well. You’ve also got the useMoreHoles option if you want more holes. Overall it’s not very complex code, so you should be able to muck about with it fairly easily. I will say that if you want a large board with a lot of holes, it may take a bit of time to render the output. (At least it does on my 2019 iMac.)

If you do a lot of soldering this may be a useful thing to speed up the process. I’m constantly looking for ways to speed things up, whether it’s single-purpose jigs or specific-use tools. Having to not think about getting it right because there’s only one way to do it is often quite helpful.

Oh, I do recommend not printing this in black. Even though I’ve got a small lamp on my workbench pointed directly at what I am soldering, the holes just don’t stand out as well as they do on a contrasting color. (Then again, I’m old and my eyesight isn’t great. Still, keep that whole “speed things up” feature in mind.)

You can get the STL and .scad file from Printables.com – Solder Board. Print it if you need it!

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REConnector PCB

This is definitely the smallest and simplest PCB I’ve ever designed. It’s 14.6mm x 7.9mm. That’s it.

But why!? Well, if you saw the last post about the Pin Bender, this is the second part… once those pins are straightened out, we put the lil PCB on there.

These rotary encoders come with right angle headers, and they work great in a breadboard, but I often have to solder wires to the rotary encoder PCB. I used to solder wires directly to the pins, and then heat shrink them on. That was terrible!

After that I desoldered the pins to get to the holes to solder on wires. That was also terrible!

I need to solder wires onto these things often enough that designing a Pin Bender and getting some PCBs fabricated totally made sense from a cost & time perspective. The PCBs are super cheap because they are so small. They serve a specific purpose, and that’s great.

Each board comes out just under 9 cents. (Not including shipping which was almost double that cost, but I ordered three different PCBs in one order.) It’s worth 9 cents on a BOM to me for the time it saves, so I consider it a win.

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Sync a Behringer TD-3 to a Pocket Operator

Last year I wrote up Syncing a Behringer RD-6 to a Pocket Operator via a Pi Pico which was more of a “wow, this works!” thing than a good explanation. I say that because a few people thought it was nice, but didn’t quite understand it, or wanted a diagram, so here’s a diagram…

The 1/8″ stereo jack on the left is where you plug in the Pocket Operator, and the 1/8″ stereo jack on the right goes to the device you want to sync up. (A Behringer RD-6 or TD-3 for example.) The ring/red is the audio side of things, the tip/orange is the click/sync signal put out by the PO, and sleeve/black is the common ground.

As previously mentioned, the Pocket Operators are awesome, and they can sync with each other, but can’t always sync with other devices. They put out a 1 volt signal for the sync track (the “click”) and most other electronic devices want something higher, like 2.5 volts, or 5 volts. The Behringer RD-6 wants over 2.5 volts, so you cannot sync it to a Pocket Operator, but now you can with this device!

This basically reads the 1 volt from the Pocket Operator, and then outputs 5 volts that the Behringer RD-6 can recognize as a sync in signal. While the RD-6 has a sync out port, there are reasons you may want to have the PO be the primary and the RD-6 be the secondary. There’s also the Behringer TD-3, which (oddly enough) does not have a sync out port.

A guy named Oscar got in touch and asked if this worked with the TD-3 and at the time I didn’t have one. Well, I have one now, and it works great. And since the TD-3 does not have a sync out port (!?!?) this is the only way (without additional hardware) to sync a TD-3 to a PO.

I built one (using a Nano, not an Uno) and I’m sending it to Oscar to test out. He’ll need to provide a USB power source and a splitter cable to get it working. (He’s got both already. Most Pocket Operator nerds probably do.)

I did make one mistake on this device… I actually incorporated labels into the enclosure. I for “In” and O for “Out” and when assembling it I didn’t notice I had it backwards until testing. Oops! So I just stuck some labels on the top, and now In is on the right and Out is on the left. If I make another, I’ll do it right next time. Oh, I also realized I could probably just build a splitter into it by adding another jack, so I may do that as well. (Though that will increase the size of the enclosure a bit.)

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Header Pin Snapper

Things have been busy lately. I’ve been building a lot of electronic devices and since there’s soldering and assembly involved I’ve been looking seriously at my tools. In some cases I’ve bought new (and better) tools, and in some cases I’ve looked at making my own tools. Here’s a “Header Pin Snapper” that makes it easy to get a 14 pin header from a longer strip.

I used to use a diagonal cutter to snip the pins to length, and that works fine if you do a few, but if you need to do a bunch a tool is a quick way to do it. I’m not the first to make one of these, you can also check out the Header Snapper – WHSN, the BlueBreaker, this Pin Header Snapping Tool, and a parametric pin header snap fixture, among many others… including the OctoSnap!

So I spent a few minutes making this simple device that can snap pin headers to a length of 14 pins. Exactly what I need, and it works fast. Working fast is often better than working slow. I didn’t need an adjustable one, or a customizable one, so this one fulfills my needs, but might not be useful for others.

It’s just three pieces of 3mm thick acrylic, and four 3mm x 12mm bolts along with four 3mm hex nuts. I’ve got plenty of small scraps of acrylic lying around so made two just in case I misplace one.

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Battery Powered Behringer RD-6 Drum Machine

I’ve got a Behringer RD-6 Analog Drum Machine and it’s battery powered! I’ve seen a number of video reviews of this machine and the reviewer always seems to say “It’s not battery powered, so you can’t easily take it with you…” But I’m here to tell you that you can take it with you (just like Steve Albini did with his Roland TR-606) and below I’ll show you how.

Here’s what you need! A Behringer RD-6 Analog Drum Machine. Any color will do. Mine is red.

A battery pack that will hold 6 AA batteries. Each battery is 1.5 volts, so 6 of them is 9 volts. (And no, a standard 9 volt battery won’t work due to the low amperage it can put out.) I had some lying around that were like this but some have connectors on them like these. As long as they have bare wires at the end, you’re good. If they do have a connector on the end you may need to chop it off. (More on that later.)

You’ll need a 2.1mm Barrel Power Jack. I usually buy a pack of them. You only need one, so find one, or buy one, or buy a bunch and have spares. (You won’t need the matching receptacle plugs. At least not for this project.)

Important! All of the barrel jacks I’ve purchased have positive in the center and negative on the outside of the barrel/sleeve. In the world of musical things (well, guitar pedals at least) negative is on the center/tip, and positive is on the outside of the barrel/sleeve.

Here’s the back of the RD-6. You can see the symbol showing negative in the center/tip. Note that it also shows 300 milliamps. A 9 volt battery is 500 milliamps, so it will work for a while, but not long. The power supply Behringer gives you is 670 milliamps, but it’s not a battery, it plugs into a wall socket.

Right so we need to… reverse the polarity! Luckily it’s as simple as switching the wires around. Normally red is positive and black is negative, but we’re switching those. Make red negative and black positive.

Here’s mine. Now, it’s worth noting that I checked all of this with a multimeter. I’d advise you to do the same. Double check your work. If you don’t know what you’re doing, ask someone for help. This probably voids your warranty, and I cannot be held responsible for what you do. On with the show!

Oh, you’ll also need batteries! Any AA batteries will do, but rechargeable are preferred, at least by me. I’m a fan of the Eneloop rechargeable batteries. I’ve got some I bought ten years ago that still work. Grab a charger and 4 batteries and, um… 4 more because you need a total of 6 batteries.

Okay, stick it all together and you get a battery powered drum machine. Boom. Tsk. Boom. Tsk. I haven’t testing how long a set of batteries will last, but I’ll add that to the list of things to do.

Now, it’s not as nice as internal batteries that are built into the case, and if I actually use this on a regular basis I might think about adding in some hook & loop to attach the battery pack to the side. It might be better to use two 3 AA battery packs wires together, since those would have a flat back that could be attached to the RD-6.