Tag Archive | "video"

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)

Tutorial: Video output from your Arduino

Create video output from your Arduino in chapter 35 of tutorials about the Arduino universe. The first chapter is here, the complete series is detailed here.

[Updated 10/01/2013]

In this chapter we will examine something different – the ability of our Arduino and compatible boards to create composite video output. In other words, displaying stuff from the Arduino on a TV. A lot of people were unaware of the ability to do this, however the process is very simple and not difficult to implement from a hardware perspective. Within this chapter we will learn to construct the minimum hardware required and demonstrate basic functions to get started.

To whet your appetite, here is a quick video demonstration of what is possible:

You can’t expect too much from a 16 MHz microcontroller without a video card… but the price is right, and with some imagination and the right functions you can do quite well. To make this happen we need to knock out some hardware of our own. Connection is very easy. First we need to locate three pins on our Arduino board. They will be used to output Sync, Video and also GND. For those with Arduino Uno/Freetronics Eleven etc Sync is digital 9, video is digital 7 and GND is … GND. If you have a Mega/Mega2560 Sync is digital 11 and video is A7. There is also the ability to generate audio with the methods in this article, and if you want to do this the Uno (etc.) pin is digital 11 or 10 on the Mega.

The monitor or television used needs to have a composite video-in socket (jack). For those with older televisions that have a VCR connected, you could use the video-in socket on the VCR. The schematic for video out is very simple, you only need two normal 0.25W resistors and a video lead:

If you’re not up for soldering into an RCA plug, a simple way is to chop up a standard video lead as such:

Then just wire the termination of the two resistors to the centre core (“pin”) and GND to the shield. For the purpose of this article I have made a quick TV-out shield that also includes a thumb joystick (as reviewed here).

A real triumph of engineering… however it solves the problem. The vertical trimmer is connected to A0;  the horizontal to A1; the button to digital 8 via a 10k0 pull-up resistor. Next, you will need to download and install the arduino-tvout library. It can be found here. We will use the TVoutBeta1.zip version.  Those of you who may have a nootropic design Hackvision – please note your library is different.

Now to see how to integrate TV-out into our sketch. We will run through the basic functions which integrated with your imagination should see some interesting results…  So let’s go!

For every project, place these two lines at the top of your sketch:

The first brings in the library, and the second line creates an instance of TV to use with the library functions. Next, we need to activate TVout and select the appropriate broadcast standard (PAL or NTSC). In void setup() use either

Now for the main functions. The first one of interest will be:

which … clears the screen. Or if you would like to fill the screen with white, use

Moving on – to write some text. First we need to select a font. There are three basic fonts to choose from:

  • font4x6 (each character being 4 pixels by 6 pixels, etc.)
  • font6x8
  • font8x8

Well there is four, but it wouldn’t display for me. Working on it! To choose a font use:

Then to write the text, choose the screen location with:

then display the text with:

You can also use TV.println(); to add a carriage return as expected. Display single characters with a position in the one function using:

So let’s have a look at the various fonts in action with the following sketch:

 

Now to move into the 1970s with some basic graphical functions. We have a screen resolution of 128 by 96 pixels to work with. When planning your display, you need to ensure that the sketch never attempts to display a pixel outside of the 128 x 96 screen area. Doing so generally causes the Arduino to reboot.

First let’s start with basic pixels. To draw a pixel, use:

where x and y are the coordinates of the pixel, and z is the colour (1 = white, 0 = black, 2 = inverse of current pixel’s colour). You want more than a pixel? How about a line:

Draws a line from x1, y1 to x2, y2 of colour colour. (1 = white, 0 = black, 2 = inverse of current pixel’s colour).

Rectangles? Easy:

Draws a rectangle with the top-left corner at x,y; width w, height h, colour and optional fill colour. Circles are just as simple:

Draws a circle with centre at x,y; radius r pixels, edge colour, optional fill colour.

Now to see these functions in action with the following sketch:

And for the video demonstration:

So there you have it, a start with Arduino and TV-out. Furthermore, a big thanks to http://code.google.com/u/mdmetzle/ for the arduino-tvout library.

LEDborder

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, or join our 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 arduino, COM-09032, education, lesson, tutorial, tv out, videoComments (42)

Kit review – nootropic design Hackvision

Hello readers

Time for another kit review – the nootropics design Hackvision,  a nice change from test equipment. The purpose of the Hackvision is to allow the user to create retro-style arcade games and so on that can be played on a monitor or television set with analogue video input. Although the display resolution is only 128 by 96 pixels, this is enough to get some interesting action happening. Frankly I didn’t think the Arduino hardware environment alone was capable of this, so the Hackvision was a pleasant surprise.

Assembly is quick and relatively simple, the instructions are online and easy to follow. All the parts required are included:

partsss

The microcontroller is pre-loaded with two games so you can start playing once construction has finished. However you will need a 5V FTDI cable if you wish to upload new games as the board does not have a USB interface. The board is laid out very clearly, and with the excellent silk-screen and your eyes open construction will be painless. Note that you don’t need to install R4 unless necessary, and if your TV system is PAL add the link which is between the RCA sockets. Speaking of which, when soldering them in, bend down the legs to lock them in before soldering, as such:

Doing so will keep them nicely flush with the PCB whilst soldering. Once finished you should have something like this:

almostdoness

All there is to do now is click the button covers into place, plug in your video and audio RCA leads to a monitor, insert nine volts of DC power, and go:

doness

Nice one. For the minimalist users out there, be careful if playing games as the solder on the rear of the PCB can be quite sharp. Included with the kit is some adhesive rubber matting to attach to the underside to smooth everything off nicely. However only fit this once you have totally finished with soldering and modifying the board, otherwise it could prove difficult to remove neatly later on. Time to play some gamesin the following video you can see how poor my reflexes are when playing Pong and Space Invaders:

[ … the Hackvision also generates sounds, however my cheap $10 video capture dongle from eBay didn’t come through with the audio … ]

Well that takes me back. There are some more contemporary games and demonstration code available on the Hackvision games web page. For the more involved Hackvision gamer, there are points on the PCB to attach your own hand-held controls such as paddles, nunchuks and so on. There is a simple tutorial on how to make your own paddles here.

Those who have been paying attention will have noticed that although the Hackvision PCB is not the standard Arduino Duemilanove-compatible layout, all the electronics are there. Apart from I/O pins used by the game buttons, you have a normal Arduino-style board with video and audio out. This opens up a whole world of possibilities with regards to the display of data in your own Arduino sketches (software). From a power supply perspective, note that the regulator is a 78L05 which is only good for 100mA of current, and the board itself uses around 25mA.

To control the video output, you will need to download and install the hackvision-version arduino-tvout library. Note that this library is slightly different to the generic arduino-tvout library with regards to function definitions and parameters. To make use of the included buttons easier, there is also the controllers library. Here is a simple, relatively self-explanatory sketch that demonstrates some uses of the tvout functions:

And the resulting video demonstration:

I will be the first to admit that my imagination is lacking some days. However with the sketch above hopefully you can get a grip on how the functions work. But there are some very good game implementations out there, as listed on the Hackvision games page. After spending some time with this kit, I feel that there is a lack of documentation that is easy to get into. Sure, having some great games published is good but some beginners’ tutorials would be nice as well. However if you have the time and the inclination, there is much that could be done. In the meanwhile you can do your own sleuthing with regards to the functions by examining the TVout.cpp file in the Hackvision tvout library folder.

For further questions about the Hackvision contact nootropic design or perhaps post on their forum. However the Hackvision has a lot of potential and is an interesting extension of the Arduino-based hardware universe – another way to send data to video monitors and televisions, and play some fun games.If you are looking for a shield-based video output device, perhaps consider the Batsocks Tellymate.

As always, thank you for reading and I look forward to your comments and so on. Furthermore, don’t be shy in pointing out errors or places that could use improvement. Please subscribe using one of the methods at the top-right of this web page to receive updates on new posts, follow me on twitter or facebook, or join our Google Group for further discussion.

High resolution images are available on flickr.

[Note – The kit was purchased by myself personally and reviewed without notifying the manufacturer or retailer]

Posted in arduino, games, hackvision, kit review, LCD, microcontrollers, notropicsComments (2)


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