If you’re just getting into hobby electronics chances are there are lots of tools you’d like to get you hands on but can’t yet justify the purchases. Why not build some of the simpler ones? Here’s a great example of a 4-channel logic analyzer that can be your next project and will add to your arsenal for future endeavors.

As you can see, [Vassilis'] creation uses a cellphone-sized LCD screen as the output. It is powered by four rechargeable batteries and driven by an ATmega8 microcontroller. He’s designed the tool without power regulation, relying on the ATmega’s rather wide range of operating voltages, and a few diodes to step down that voltage for the LCD screen.

As you can see in the clip after the break, alligator leads can be used to connect the test circuit to the inputs (don’t forget the ground reference!). Thee buttons at the bottom let you navigate the captured data by panning and zooming. Perhaps the best design feature is the single-sided circuit board which should be quite easy to reproduce at home.

[via Dangerous Prototypes]

[Andrzej] loves his Nokia N900, noting that it makes a great portable gaming device. Since it supports a wide array of emulators, it’s perfect for indulging his gaming nostalgia on the go. He says that the one downside to the N900 is that its keyboard doesn’t make gaming easy, nor comfortable.

To make gaming a big more fun, he built himself an add-on gamepad that fits perfectly over the phone’s keyboard. Connected via the phone’s USB port, it features 8 push buttons along with a PSP joystick. He used an ATmega8A as the brains of the controller, communicating with the phone as a USB keyboard. He says that this sort of configuration makes it extremely easy to do all sorts of custom button mapping on a per-game basis.

As you can see in the picture above the controller is currently lacking a case, but we think that with a bit of clever packaging, it could look as nice as a retail add-on.

Check out the short video below to see his gamepad in action.

Why not that is, if you have a prosthetic arm. Although it’s hard to believe we haven’t seen this before, [Trevor Prideaux], according to [The Telegraph's] article, “has become the world’s first ever patient to have a smartphone docking system built into his prosthetic arm.”

[Trevor] was born without a forearm, and, as he puts it, he’s used to adapting to things.  However, he thought others might be struggling with the same problem, especially those that become disabled later in life. Once their help was secured, Nokia and the Exeter Mobility Centre got to work on his new limb and produced a prototype in five weeks!

[Trevor] is quite pleased with his new phone docking system. Texting especially is much easier and safer, and the phone can be removed when needed for making calls. We love to see hacks like this where people enhance their abilities using technology! For another hack helping those with disabilities, check out this wheelchair elevator/winch made for a non-accessible apartment.

via [reghardware.com]

It’s been a while since we checked in on [Travis Goodspeed]. His latest post makes RF sniffing with the Next HOPE badge more portable by ditching the need to display data on a computer. He’s built on the work he did at the beginning of the year, replacing the FTDI chip on the badge with a Bluetooth module. Now he can use his Nokia N900 as a GoodFET terminal to not only display the packets pulled from the air, but the control the badge as well.

Previously, the client running on the computer was communicating with the badge via a serial connection. To get it working on the N900 [Travis] transitioned from using py-serial over to using py-bluez. All of the code changes are available from the GoodFET repository.

He’s got a few other tricks planned for this concept. He put in a parts order to add Bluetooth to the Girltech IM-ME. The pretty pink pager has the same radio chip on board, so adding Bluetooth connectivity will allow it to be used in the same way. There are also plans in the works to add a couple other packet sniffing protocols to the bag of tricks, including ZigBee.

[JB's] driving a Nokia 6100 LCD using an MSP430 with input from a Wii Nunchuck. He’s using the G2211 microprocessor that came with the Launchpad, and developing his code with MSP-GCC. As you can see in the video after the break, this works but there’s some room for improvement. That’s being said, he is bumping up against the code memory limit, with just around 500 bytes left to work with. The LCD screen is SPI and currently it’s hogging the pins that are used for the hardware i2c. Since he needs an i2c bus to talk to the nunchuck he had to go with software i2c which explains part of his program memory troubles.

We’re in no way experts on this, but it seems like he could save space (and improve the input responsiveness) by rewriting his LCD drivers in order to remap the pins. Then again, it might just be better to move up to a larger MSP430. If you’ve got some advice, make sure to share it by leaving a comment.

[Maurizio] was having some reception issues with his wireless internet and set out to add an external antenna to the USB dongle (translated). He had previously poked around inside of the Nokia internet key to find that the internal antenna was a flexible circuit substrate wrapped around a plastic box that made contact with main circuit board via a spring connector. This plastic frame is just right for mounting an SMA connector in just the right place for it to stick out the end of the case as seen in the picture above. It gives him better range, but since speed depends on how much traffic the wireless node is under, it’s not a guarantee that you’ll get a snappier connection after this hack.

If you’re a soldering ninja this FM transmitter bug is for you. It’s quite similar to the one we looked at yesterday, but this uses 100% salvaged parts. Two phones donated components; a Nokia 3210 for its voltage-controlled oscillator and a Nokia 1611 for the rest of the parts. The bad news is that mobile technology like cellphones use some of the smallest surface mount packages known to man. That’s where the soldering skill come into play. The good news is that if you’ve been scavenging for discarded phones in order to reuse their LCD screens you already have these parts on hand.

[Thanks George]

[Rossum's] taking a look at the Nokia LCD screens that are both plentiful and begging to be bent to your will. For quite some time the Nokia 6100 screens have been used in a lot hacks, but he wanted to see what else is out there. He digs into his junk box of cell phones and comes up with a couple to test; the Nokia 6101 and Nokia 2760. The screens use a 3-wire SPI interface, which he sniffs out with a logic analyzer. At power-up the cellphone polls the screen to determine which type of LCD controller is connected. [Rossum] grabs these commands from the logic analyzer and uses it to determine the hardware in use with each screen.

He made himself a nice breakout board which has connectors for several different screens. The firmware he’s using detects when a screen is attached and switches to the applicable protocol for that display. Take a look at the video after the break.

In this instructible, [wkter] takes us through the process of running a Nokia 3310 LCD display using an ATmega8.  This instructible isn’t a beginners project as he assumes you already have a strong understanding of how to work with these components and their programming languages. He is very thorough with information though, providing datasheets, pinout diagrams, and source code. Once you get this down, you could go a little further and make  Conway’s game of life.

[Jethomson] worked out a way to use a Nokia USB cable at a USB to Serial cable. He was able to pick up one of these cables for less than $3 delivered. A little probing worked out which conductors go with the appropriate signals and from there he developed a way to protect the 3.3v signal levels with a voltage divider.

It’s not surprising that this works, having seen [Will O'Brien's] post covering serial communications on Nokia phones. In that post we learned that the Nokia phones are using TTL communications. Once you’ve completed [Jethomson's] modifications to the cable you can follow his examples for using this in conjunction with an Arduino.

[Miguel A. Vallejo] wanted a portable spectrum analyzer for the 2.4GHz ISM band. No problem, there’s modules for that are easy to interface with a microcontroller and LCD screen. But carrying around a black project box doesn’t exactly scream ‘cool’ so he fit his spectrum analyzer inside of a cell phone. This made a lot of things easier for him; he already had a few old phones, he was able to use both the original battery and the original LCD screen, and a lot of the mounting work is already done for you. The only challenge was to fit his custom circuitry inside. By hacking off part of the CYWM6935 module and cutting some protoboard in the same shape as the original PCB he managed to get everything into this tiny portable package. Now he’s looking for a way to incorporate a charger, and an on/off switch.

If you don’t have an old cell phone sitting around you can try building a spectrum analyzer that uses a character display. But we’d suggest hitting up your friends for their old cellphones.  The screens are used in all kinds of fun projects.

Just when you think you’ve heard all you can about the N900 PUSH competition, we have some more news for you.

The original PUSH competition was only for UK members, but now Nokia has introduced the ‘Mod in the USA‘ N900 PUSH competition. Similar to the original, anyone (within region) can submit a cool mod, hack, useful creation that would use the N900. Winners will be selected, and thats when the differences start.

There will be a $10,000 for 1st prize, and smaller prizes for 2nd and 3rd. Plus a trip to Vegas to showcase the 3 winning hacks at CTIA 2010 as well as funding, N900s and support to build the mods.

Don’t have an idea but still want to try? They have a discussion group to get the juices flowing, or you could always discuss in our comments.

[Update: The original PUSH competition was actually world wide. Thanks Matt and Ricardo]

Not too long ago we asked our readers what they would like to hear about from the PUSH N900 winners and their hacks. We got some silly questions, and some serious, we asked both and now the PUSH teams have answered.

The day has passed, the party is gone, and all that’s left is the final interview. The Light Hack Crew gave us a somewhat shorter response then what we were used to, but it turned out to be just as sweet.

>Thank you for taking the time to answer some questions for HackaDay. We love when a hacker is willing to share their work with us.

>How did you and your team get together? Any fun backstory you care to share?

LIGHTHACK CREW is a trio of 3 crazy coconuts from Perth, Australia . [Dave] and [Tom] have been friends from way back, and [Sharna] is a friend from way, way back,

>Have you and your team worked on any other projects? Cellular related projects? N900 projects?

No this is our first one together.

>What was your main inspiration for your team’s project?

It was [Tom’s] idea for focusing the project of light graffiti, and that made me think of [Sharna] as she is a graffiti stencil artist.

> How do you think people will react when you finish/release?

People will love it as it is fun to create light graffiti and easy to do, all you need is the hacked N900 and the electronic LED can.

>Do you have any future plans with your team? Continued N900 development? Update your current projects?

Hopefully continued development of the Light Hack software and bring it to other devices

>What do you think of the other winners?

well as a skater, long boards mainly, I’m interested in the soldering skaters team, the others are great too,

>Questions from our commentators.

>What are you thoughts on Arduino? Do you intend to use one in your project?

[Tom] is the electronic genius,­ but I’d say he found the Arduino pretty straightforward.

>How is working with the N900 hardware and software?

Great from the little I have looked at and used, the phone is very powerful, its not running a snapdragon but damn can it multi task! the open source Maemo OS is very cool, the fact that it is linux makes it so much easier to develop for, as so much is setup for it already – SDK installed VM image is the way to go.

>What do you think about the movement of cell phones towards open source software, such as the Maemo? Do you plan to, or have you ever tried Android?

I think its great, I tried the iphone, but objective C was new to me, along with the $100!, haven’t had the time for android yet. But would like to check it out.

>(If you use a secondary power source, example – to run motors) What kind of battery life is expected for your project?

We use 4 AA or 4 AAA batteries at the moment. Im sure we could wire up any sort of battery. The battery life isn’t too bad, as the Bluetooth really only is used when the buttons are pressed, and the LED’s are quite efficient.

>Can we get a list of what you’re using in your project? (example – bluetooth sets, motors, dedicated sensors, etc)

HARDWARE: Bluetooth module, PIC microcontroller

SOFTWARE: I used C, for the language, GStreamer framework for capturing the video, and some basic algorithms for image processing: subtraction and a moving average filter for noise removal.

>And yes, we actually had a reader (Joe) ask the following (feel free to omit)

>How often do you change your underwear? Underwear?

Its 38 degrees im just wearing my boardies J

Thank you again!

Like all great things, they must come to an end. As such, at 10am PST, this morning – our N900 Push competition came to a close. We had some really awesome answers, some really round about, and of course the obligatory – really bad ones. For those that are just on the EDGE of your seat waiting for the final concluding answer to stop the arguing and fighting – to settle this whole dispute. The answer, and the winners are…After the break.

Just to recap, the question -

You’re working with any one of the team winners in the PUSH N900 competition. Your team needs two like resistors in order to complete the project on time.

Luckily your work drawer is overflowing with resistors, and you know that there are only 4 different values since you pulled them yourself from old junk.

You close your eyes and reach in. What is the minimum amount of resistors you have to pull out to ensure 2 of the same value?

The Correct answer is 5 resistors. [Talin Salway],  [Sari Ibrahim], [James R. Smoot], [Jody Halyk], and [Thomas Remmert] all sent in the correct answer, were picked by us, and gracefully pass their tickets to another winner. In the end [Robrecht Noens] was the only one to respond within our 24 hour limit claiming tickets. Congratulations, and hope you have fun at the N900 PUSH Showcase [Robrecht]!

For all those that sadly, did not win. You can still keep up on the party, [Matt] let us know…

We’ll be updating our @PUSHN900 Twitter account regularly using the #PUSHN900 hashtag to help follow what you guys are saying.
We’ll be uploading video using Qik.com/PUSHN900
Keep checking the PUSH N900 Facebook page for updates as well.

And finally an explanation: The entire riddle (as a lot of readers repeated to us in the entries) is based on the Pigeonhole Principle. In the worst case scenario, you reach in and pull out 4 different values. Thus, you must pull out 5 to ensure at least 2 match.