PIC 18F4550 dev board

[Natsfr] was looking for a single-sided PCB to host a PIC 18F4550. Not finding one he designed his own in Kicad and is sharing (translated) the spoils of his labor.

This chip has USB capabilities which is why we see it used in a ton of projects. Almost all of them (including this USB input device post) use a very large DIP package. [Natsfr] went a different route, designing for the TQFP package to keep the drilling ot a minimum. The layout includes a crystal and USB-mini port, but it also breaks out the I/O pins on the chip. The red box above shows the quick fix he used on the VCC line as the board trace was shorting on the USB jack housing.

He didn’t drill out the holes for most of the breakout pins on this prototype. There’s just one header populated for programming the PIC chip. But he does have some plans for the first board. He’s going to use [Texan’s] AVR programming firmware for PIC to turn it into a USB AVR ISP programmer.

Prototyping with very, very small ICs

Gone are the days when all the cool chips are able to be thrown into a breadboard very easily. [starlino] was working with a circuit that uses an accelerometer, but unfortunately these chips come in hard to solder LGA-16 packages. [starlino] figured out a way to prototype with these packages that doesn’t require a custom breakout board or spending any time watching a reflow oven.

[starlino]’s LGA-16 adapter board began with a piece of perf board drilled out to form a space that perfectly fits his accelerometer. A piece of tape is placed over the pads of the chip and perf board, and the gap between the chip and board is filled in with a two-part plumbers putty.

Once the putty has cured, the leads on the acclerometer are connected to the pads on the board with a silver conductive pen. After putting a few header pins in the corners of the board, [starlino] soldered the pads to the pins and had a permanent breakout board for a very small accelerometer.

It’s not by any means a pretty build, but after [starlino] sealed the entire build in liquid electrical tape and installed it in a DIP socket, he had a completely functional accelerometer in an easy to prototype package. Not bad for a breakout board that can be built from stuff just lying around a workbench.

Giving an ATX bench supply the case it deserves

Your bench supply doesn’t need to look sad just because you’re using an ATX power supply instead of a commercial product. Follow [Ian Lee’s] example and you could have beautiful wooden enclosures for the tools in your own shop.

The woodworking skills used here aren’t all that advanced, but you need to have a knack for it so we suggest running some test pieces before you start the actual build. [Ian] ran a dado for the front and back panel in each piece of the wood sides. At each corner the inside of the the pieces were mitered at 45 degrees. To put it all together he laid the pieces end to end on a the work bench, then applied painters tape to the outside of the joints. This holds the joints together so that he can flip the collection over, apply glue, and then start hinging the sides into place. It’s almost like rolling up a box.

As with other ATX supply projects we’ve seen [Ian] designed this so that the PSU can be swapped out later if necessary. Instead of wiring his own cable harness he used an ATX breakout board. To get the interface layout he wanted he mounted the banana jacks separately and just ran jumper cables back to that board.

Resizable ARM dev board; just take some off the top

[Bob Alexander’s] most recent project is a hack saw resizable ARM breakout board. He wanted to start using more ARM microcontrollers in his projects and went for a breadboard friendly design. It uses a 40-pin dip package, but if you need the horsepower but not the I/O you can literally cut it down to size. We might recommend grabbing some tin snips, which can cut through a PCB like butter, but to each his own.

The board is based around an STM32 chip. You’ll find a crystal oscillator for the system clock, and a clock crystal if you need it. On the other side of the chip he included a footprint for a voltage regulator. This setup provides a remarkable range of input voltages, accepting from 2 to 3.6 volts without the regulator, and up to 16 volts if the regulator is present. He designed a package footprint that can be easily bridged if there’s no SMD part there. Just make sure you insulate that pad if you are using one with a conductor on the bottom. He explains this in detail in his writeup.

You’ll need a programmer to work with the board. He uses an STM32 Discovery Board for this but there are quite a few other options out there too.

[Scot] whips up breakout board for his ARM breakout board

[Scot Kornak] got his hands on the new STM32 Discovery Board. He got his as a free giveaway, but at only $18 he probably would have picked one up anyway. His one complaint about the device is that he dual pin-headers which break out the ARM processor’s pins are not the most convenient for hooking up external components. He decided to make his own breakout board which would give him a more robust solution for the components he uses all the time.

The protoboard that he chose as a base is quite interesting. It’s made for interfacing DIL pin headers just like the ones on the STM32F4 Discovery board. Each row of the dual header is carried down the board perpendicular to those headers. [Scot] cut the traces underneath the STM32 board to isolate the right and left sides. He then added RS232 hardware to one side, while including another pair of DIL headers to break out the rest of the unused pins.

This is all he’s got so far, but there’s plenty of room on the base board to add more as the need arises.

DIY breadboard modules for easy prototyping

[Rajendra] got tired of building the same basic circuits time and again on the breadboard. He decided to build some simple, modular circuits on protoboard and make them easy to interface with the breadboard. As you can see, he ended up with seven modules that make prototyping faster and easier.

At first glance some might not seem all that beneficial. For instance, making a board for an 18-pin PIC microcontroller into a single-in-line form factor would seem like you’re actually wasting breadboard space when compared to the DIL package of the chip. But consider that the oscillator and its capacitors, reset button, and programming header are also on the breakout board and will not have to be built in place. There are also several I/O boards, one with five buttons, another with an LED bar graph, and a set of LEDs with a SIL resistor package on-board. These modules can be plugged into a breadboard and wired up with jumper wires, or connected directly to the same rows as the microcontroller module.

Making a 3D printer work wirelessly

Looking for more ways to enhance his 3D printer, [JJ] decided to make it wireless. He got his hands on some $10 Bluetooth modules and figured this would be just the thing to make the link with his laptop.

They came as surface mount modules, so the first thing he had to do was develop a breakout board that he could patch into his Ultimaker 3D printer. This provided a nice opportunity as he needed to do some level converting to make the 3.3V module play nicely with his 5V CNC electronics. The first version of the board turned out well but he had really a poor communications range. The second version, which is pictured above, hangs the module’s antenna off the edge of the breakout board and works a lot better.

We’ve embedded a clip after the break that walks through the development of this board. [JJ] shared the Eagle CAD files as a megaupload link, but we’ve also mirrored the file after the break for your convenience.

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