Tag Archive | "SMT"

Review – Schmartboard SMT Boards

In this article we review a couple of SMT prototyping boards from Schmartboard.

Introduction

Sooner or later you’ll need to use a surface-mount technology component. Just like taxes and myki* not working, it’s inevitable. When the time comes you usually have a few options – make your own PCB, then bake it in an oven or skillet pan; get the part on a demo board from the manufacturer (expensive); try and hand-solder it yourself using dead-bug wiring or try to mash it into a piece of strip board; or find someone else to do it. Thanks to the people at Schmartboard you now have another option which might cost a few dollars more but guarantees a result. Although they have boards for almost everything imaginable, we’ll look at two of them – one for QFP packages and their Arduino shield that has SOIC and SOP23-6 areas.

boards

QFP 32-80 pin board

In our first example we’ll see how easy it is to prototype with QFP package ICs. An example of this is the Atmel ATmega328 microcontroller found on various Arduino-compatible products, for example:

atmega

Although our example has 32 pins, the board can handle up to 80-pin devices. You simply place the IC on the Schmartboard, which holds the IC in nicely due to the grooved tracks for the pins:

atmegabefore

The tracks are what makes the Schmartboard EZ series so great – they help hold the part in, and contain the required amount of solder. I believe this design is unique to Schmartboard and when you look in their catalogue, select the “EZ” series for this technology. Moving forward, you just need some water-soluble flux:

fluxpen

then tack down the part, apply flux to the side you’re going to solder – then slowly push the tip of your soldering iron (set to around 750 degrees F) down the groove to the pin. For example:

Then repeat for the three other sides. That’s it. If your part has an exposed pad on the bottom, there’s a hole in the centre of the Schmartboad that you can solder into as well:

qfpheat

After soldering I really couldn’t believe it worked, so probed out the pins to the breakout pads on the Schmartboard to test for shorts or breaks – however it tested perfectly. The only caveat is that your soldering iron tip needs to be the same or smaller pitch than the the part you’re using, otherwise you could cause a solder bridge. And use flux!  You need the flux. After soldering you can easily connect the board to the rest of your project or build around it.

Schmartboard Arduino shield

There’s also a range of Arduino shields with various SMT breakout areas, and we have the version with 1.27mm pitch SOIC and a SOT23-6 footprint. SOIC? For example:

soicic

This is the AD5204 four-channel digital potentiometer we used in the SPI tutorial. It sits nicely in the shield and can be easily soldered onto the board. Don’t forget the flux! Although the SMT areas have the EZ-technology, I still added a little solder of my own – with satisfactory results:

The SOT23-6 also fits well, with plenty of space for soldering it in. SOT23? Example – the ADS1110 16-bit ADC which will be the subject of a future tutorial:

ads1110

Working with these tiny components is also feasible but requires a finer iron tip and a steady hand.

sot236

Once the SMT component(s) have been fitted, you can easily trace out the matching through-hole pads for further connections. The shield matches the Arduino R3 standards and includes stacking header sockets, two LEDs for general use, space and parts for an RC reset circuit, and pads to add pull-up resistors for the I2C bus:

otherparts

Finally there’s also three 0805-sized parts and footprints for some practice or use. It’s a very well though-out shield and should prove useful. You can also order a bare PCB if you already have stacking headers to save money.

Conclusion

If you’re in a hurry to prototype with SMT parts, instead of mucking about – get a Schmartboard. They’re easy to use and work well.  Full-sized images available on flickr.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

The boards used in this article were a promotional consideration supplied by Schmartboard.

*myki

Posted in arduino, product review, review, safety, schmartboard, SMD, SMT, soic, soldering, sot-23, tqfp, tronixstuff, tutorialComments (2)

Kit Review – SC/Jaycar USB Power Monitor

Introduction

Every month Australian electronics magazine Silicon Chip publishes a variety of projects, and in December 2012 they published the USB Power Monitor by Nicholas Vinen. Jaycar picked it up and now offers a kit, the subject of our review. This small device plugs inline between a USB port and another device, and can display the current drawn, power and voltage at the USB port with a large LCD module. This is useful when you’re experimenting with USB-powered devices such as Arduino projects or curious how external USB devices can affect your notebook computer’s battery drain.

Assembly

The kit arrives in typical Jaycar fashion:

… everything necessary is included with the kit:

The instructions arrive as an updated reprint of the original magazine article, plus the usual notes from Jaycar about warranty and their component ID sheet which is useful for beginners. The PCB is quite small, and designed to be around the same size as the LCD module:

As you can see below, most of the work is already done due to the almost exclusive use of SMD components:

That’s a good thing if you’re in a hurry (or not the best with surface-mount work). Therefore the small amount of work requires is simply to solder in the USB sockets, the button and the LCD:

It took less than ten minutes to solder together. However – take careful, careful note of the LCD. There isn’t a pin 1 indicator on the module – so instead hold the LCD up to the light and determine which side of the screen has the decimal points – and line it up matching the silk-screening on the PCB. Once finished you can add the clear heatshrink to protect the meter, but remember to cut a small window at the back if you want access to the ICSP pins for the PIC microcontroller:

How it works

The USB current is passed through a 50 mΩ shunt resistor, with the voltage drop being measured by an INA282 current shunt monitor IC. The signal from there is amplified by an op amp and then fed to the ADC of a PIC18F45K80 microcontroller, which does the calculations and drives the LCD. For complete details purchase the kit or a copy of the December 2012 edition of Silicon Chip.

Operation

First you need to calibrate the unit – when first used the meter defaults to calibration mode. You simply insert it into a USB port. then measure the USB DC voltage brought out to two pads on the meter. By pressing the button you can match the measured voltage against the display as shown below – then you’re done.

Then you simply plug it in between your USB device and the socket. Press the button to change the measurement. The meter can measure the following ranges:

For an operational example. consider the next three images are from charging my phone – with the power, current and voltage being shown:

“P” for power…

current in mA

“b” for bus voltage

If you want to use the USB ports on the right-hand side of your computer, just press the button while inserting the meter – and it flips around:

Finally – here’s a quick video of the meter at work, whilst copying a file to an external USB hard drive:

Conclusion

I really like this – it’s simple and it works. Kudos to Nicholas for his project. You can purchase it from Jaycar and their resellers, or read more about it in the December 2012 edition of Silicon Chip. Full-sized images available on flickr. This kit was purchased without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in jaycar, kc5516, kit review, monitor, power, silicon chip, USB

Adventures with SMT and a POV SMT Kit

Introduction

There’s a lot of acronyms in the title for this article – what I wanted to say was “Adventures with surface-mount technology soldering with the Wayne & Layne Blinky Persistence-of-vision surface-mount technology reprogrammable light emitting diode kit…” No, seriously. Anyhow – after my last attempt at working with hand soldering surface-mount components couldn’t really be called a success, I was looking for something to start again with. After a little searching around I found the subject for today’s review and ordered it post-haste. Delivery from the US to Australia was twelve calendar days – which is pretty good, so you know the organisation is shipping quickly once you paid.

The kit is by “Wayne and Layne” which was founded by two computer engineering graduates. They have a range of open-source electronics kits that look like fun and a lot of “blinkyness”. Our POV kit is a simple persistence-of-vision display. By using eight LEDs in a row you can display words and basic characters by waving the thing through the air at speed, giving the illusion of a larger display. An analogy to this would be a dot-matrix printer that prints with ink which only lasts a fraction of a second. More on that later, first – putting it together.

Assembly

Like most other kits it arrived in an anti-static bag, with a label clearly telling you where the instructions are:

Upon opening the amount of items included seemed a little light:

However the instructions are detailed:

… and upon opening, reveal the rest of the components:

… which are taped down to their matching description on the cardboard. When cutting the tape to access the parts, do it slowly otherwise you might send them flying off somewhere on the bench and spend ten minutes looking for it. Finally, the PCB in more detail:

After reviewing the instructions, it was time to fire up my trusty Hakko and get started. At this point a few tools will come in handy, including SMT tweezers, some solder wick and a piece of blu-tac:

Following the instructions, and taking your time are the key to success. When mounting the two-pad components – put a blob of solder on one pad, then use tweezers to move the component in whilst keeping that pad of solder molten, remove the iron, then let go with the tweezers. Then the results should resemble capacitor C1 on the board as shown below:

Then a quick blob at the other end seals it in. This was easily repeated for the resistors. The next step was the pre-programmed PIC microcontroller. It is in the form of a SOIC package type, and required some delicate work. The first step was to stick it down with some blu-tac:

… then solder down one pin at each end. Doing so holds it in place and you can remove the blu-tac and solder the rest of the pins in. I couldn’t solder each pin individually, so dragged solder across the pins then tried to soak up the excess with solder wick. I didn’t find this too successful, so instead used the solder sucker to mop up the excess:

suckersmall

If you solder, you should get one of these – they’re indispensable. Moving forward, the PIC finally sat well and looked OK:

Next was the power-switch. It clicks neatly into the PCB making soldering very easy. Then the LEDs. They’re tiny and some may find it difficult to identify the anode and cathode. If you look at the top, there is a tiny dot closer to one end – that end is the cathode. For example, in the lineup:

Soldering in the LEDs wasn’t too bad – however to save time do all the anodes first, then the cathodes:

At this point all the tricky work is over. There are the light-sensor LEDs and the reset button for the top:

And the coin-cell battery holder for the bottom. The battery is also included with the kit:

Operation

Once you’ve put the battery in, turn it on and wave it about in front of yourself. There are some pre-programmed messages and symbols already loaded, which you can change with the button. However you’ll want to put your own messages into the POV – and the process for doing so is very clever. Visit the programming page, and follow the instructions. Basically you enter the text into the form, set the POV to programming mode – and hold it up against two squares on your monitor. The website will then blink the data which is received by the light-sensitive LEDs. Once completed, the POV will inform you of success or failure. This method of programming is much simpler than having to flash the microcontroller every time – well done Wayne and Layne. A pin and connector is also included which allows you to wear the blinky as a badge. Maybe at a hackerspace, but not in public.

Once programmed some fun can be had trying out various speeds of waving the blinky. For example, here it is with the speed not fast enough at all:

… and a little bit faster:

And finally with me running past the camera:

Furthermore, there is an ‘easter egg’ in the software, which is shown below:

Conclusion

We had a lot of fun with this simple little kit, and learned a thing or two about hand-soldering SMT. It can be done with components that aren’t too small – however doing so was an interesting challenge and the results were quite fun. So it met our needs very well. Anyone can do it with some patience and a clean soldering iron. You can order the Blinky POV SMT kit directly from Wayne & Layne. Full-sized images available on flickr. This kit was purchased without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in blinky pov, kit review, review, SMT, soldering, tutorial, wayne and layneComments (1)

SMD Soldering made easier

Hooray – we’re back…

SMD (surface mount device) soldering to some people can seem scary and dangerous. And if done incorrectly, or in the wrong state of mind, and/or with the wrong equipment – it can be. Or like myself, you could be pretty bad at it. To make things easier, I’d like to point you in a few directions to find help and guidance if this technique is new to you. Furthermore, if you find any more resources, leave a comment below and we will investigate them further.

First up we have a new comic from Greg Peek and Dave Roberts from siliconfarmers.com, (written in a similar vein to the “Soldering is Easy” comic that was released in 2010) that is easy to read and makes sense. Here is the cover:

smtcomic

As you can see from the CC logo on the title page, the comic is in the public domain, so please print it out, email it, and generally distribute it far and wide. For more information about the authors see their website at siliconfarmers.com. I have also placed the file here at tronixstuff for you to download.

Next we have a detailed and nicely illustrated tutorial by Jon Oxer from freetronics.

Jon runs through the process of soldering with a toaster over, with great success. So head over and have a read.

For the first video tutorial we have the SMD episide of the series by David L. Jones at eevblog, well worth the time:

Next, the people from Sparky’s Widgets doing some drag soldering:

That’s all we have for now, so if you find any more that are worthwhile leave a comment below.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in education, hardware hacking, SMD, soldering, tutorialComments (4)

Experimenting with Surface-Mount Component Prototyping

Experimenting with hand-soldering SMT components.

Updated 18/03/2013

Now and again I have looked at SMT (surface-mount technology) components and thought to myself “I should try that one day”. But not wanting to fork out for a toaster oven and a bunch of special tools I did it on the cheap – so in this article you can follow along and see the results. Recently I ordered some ElecFreaks SOIC Arduino Mega-style protoshields which apart from being a normal double-sided protoshield, also have a SOIC SMT pad as shown below:

First up I soldered in two SOIC format ICs – a 555 and a 4017:

These were not that difficult – you need a steady hand, a clean soldering iron tip and some blu-tac. To start, stick down the IC as such:

… then you can … very carefully … hand-solder in a few legs, remove the blu tac and take care of the rest …

The 4017 went in easily as well…

…however it can be easier to flood the pins with solder, then use solder-wick to soak up the excess – which in theory will remove the bridges between pins caused by the excess solder. And some PCB cleaner to get rid of the excess flux is a good idea as well.

Now to some smaller components – some LEDs and a resistor. These were 0805 package types, which measure 2.0 × 1.3 mm – for example a resistor:

The LEDs were also the same size. Unlike normal LEDs, determining the anode and cathode can be difficult – however my examples had a small arrow determining current flow (anode to cathode) on the bottom:

Another way is to use the continuity function of a multimeter – if their output voltage is less than the rating of the LED, you can probe it to determine the pins. When it glows, the positive lead is the anode. Handling such small components requires the use of anti-magnetic tweezers – highly recommended…

… and make holding down the components with one hand whilst soldering with the other much, much easier. Unlike normal veroboard, protoshield or other prototyping PCBs the protoshield’s holes are surrounded with a “clover” style of solder pad, for example:

These solder pads can make hand-soldering SMT parts a little easier. After some experimenting, I found the easiest way was to first flood the hold with solder:

… then hold down the component with the tweezers with one hand while heating the solder with the other – then moving and holding one end of the component into the molten solder:

The first time (above) was a little messy, but one improves with practice. The clover-style of the solder pads makes it easy to connect two components, for example:

With some practice the procedure can become quite manageable:

As the protoshields are double-sided you can make connections between components on the other side to keep things neat for observers. To complete the experiment the six LEDs were wired underneath (except for one) to matching Arduino Mega digital output pins, and a simple demonstration sketch used to illuminate the LEDs, as shown below:

For one-off or very low-volume SMD work these shields from elecfreaks are quite useful. You will need a steady hand and quite a lot of patience, but if the need calls it would be handy to have some of these boards around just in case. For a more involved and professional method of working with SMT, check out this guide by Jon Oxer.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in 555, education, elecfreaks, learning electronics, SMD, soldering, tutorialComments (6)


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