Prototyping With A GPS Module

April 12, 2011 by Mike Szczys 16 Comments

[Oneironaut] is trying out a new GPS module with the prototype seen above. It’s a San Jose Navigation device identified as FV-M8 and sold by Sparkfun for just under a hundred bucks. That’s it hanging off the bottom-right of the breadboard seen above. They’ve packed a lot of power into the small footprint, and made it very easy to control at the same time. Although the device is fully configurable, you can start grabbing serial data from it just by connecting a single data line, 3.3V, and ground.

[Oneironaut] tests it out by streaming the serial data to a character LCD screen, then comparing the output to his handheld Garmin GPS device. You can see him describe his ATmega32-based test platform in the video after the break. We’re used to seeing spy-tech for most of his projects and this will eventually join those ranks. He’s thinking of putting together a magnetic tracking module that plays nicely with Google Earth.

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Shift Register Is All It Takes To Make A 3-wire Serial LCD

April 7, 2011 by Mike Szczys 11 Comments

This hack is a bit older, but one aspect of the setup makes it worth sharing. Shift registers are a common component to include in a project when you need to increase the number of I/O pins available. We’ve used them to drive LCD screens before, but we never realize you could use a 595 chip to make a 3-wire serial LCD interface. That’s because we’ve always thought of shift registers as having three control pins which must be addressed: data, clock, and latch. But it seems that’s not the case. This hack gangs the pins for clock and latch (called the storage register clock input on this chip) together. This causes the shifted data to be latched to output register one clock cycle after it is shifted into the chip.

This means you can operate the 595 chip with just two pins, but alas, you do need one more connection to drive the LCD properly. This is an HD44780 compliant display. It is being used in 4-bit mode; four of the shift register pins provide that data, while a fifth controls the Register Select pin. Since the shifted data from the 595 appears on the pins after each clock strobe, you must control the Enable pin on the LCD separately or it will behave sporadically.

So there you have it, control an HD44780 display with just 3-pins by using a $0.42 part. Are we going a little too fast for you? Check out this 595 tutorial and give the shift register simulator a try. That should bring you up to speed.

[Thanks Rajendra]

Virtual Serial Bridge

March 24, 2011 by Kevin Dady 10 Comments

When you are running emulators or virtual machines it may be sometimes handy to be able to connect a serial port from the guest machine to the host machine. [Aurimas] had that issue, and also had a fun fix for that using 2 USB <> Serial adapters, but as you can imagine that is not a ideal solution, enter the Virtual Serial Bridge.

Digging around Vmware it was found that the support for what he needed was there, but not really used. A little addition of a few lines to the guest OS vmx file and configuring the socat multipurpose relay package. Though the instructions revolve around the Mac platform as the host and Windows as the guest socat and Vmware you can probably mix it up with any software that uses the serial port and a *x or windows host.

The Basics Of Controlling An Arduino With PHP

March 17, 2011 by Mike Szczys 23 Comments

You can easily add Internet-based control for your Arduino if it is close enough to your server to be connected via USB. This tutorial will give the basics you need to get it working.

The gist of this method involves a webpage that includes PHP elements. When one of those elements is manipulated, a command is sent via serial connection to the Arduino which then reacts based on what it received. This example uses an Ubuntu box that is running an Apache server. The Arduino sketch sets up the serial connection and then listens for incoming traffic. Whenever it receives a non-zero character an LED will blink. On the server side of things you’ll need to make sure that the system user that runs Apache (www-data) has permission to write to a serial port.

This base example may seem extremely simple, but there’s no end to what you can build on top of it. Different PHP events can be added to push new commands over the serial connection with matching test conditions added to the sketch.

[Thanks Jarryd]

Interfacing An Arduino With A TFT LCD

February 21, 2011 by Mike Nathan 8 Comments

tft_lcd

Seven-segment displays and monochrome LCDs are fine for most projects, but some things simply look better in color. [John] over at the Little Bird Electronics blog recently wrote up a tutorial demonstrating the use of a TFT LCD panel with an Arduino. The specific panel he chose was a 4D Systems 1.44” TFT LCD that happened to feature a dedicated graphics processor, which should allow for some fantastic visuals when used to its fullest potential.

The LCD takes its commands over a serial interface, making it a simple five-wire display solution for your projects. The display can be programmed manually by sending hex commands over the serial interface, but there are also some user-developed libraries available that will allow you to use the majority of the most popular functions without the learning curve. One thing to note is that the LCD must be flashed with a particular flavor of firmware before it can communicate over the serial interface, a process for which [John] provides a walk through.

The LCD panel can be used with any Arduino-compatible board, so it can be useful in a whole host of projects.

Stick around to see a simple demo of the board in use.

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Patching Into An Optical Mouse With A PIC

January 28, 2011 by Mike Szczys 12 Comments

[MikyMouse] cracked open a couple different optical mice (or is it mouses?) in order to play with the data communications coming off of the chips inside. Once he figured out the protocol, it wasn’t too hard to grab the data for use in his own projects. The chip that controls the mouse is one of two he looked at, either an ADNS2051 or an ADNS2610. They run at 5V and use serial communications via SDIO and SCK pins. The clip after the break shows the test apparatus displaying coordinates of the mouse on an LCD screen. This seems like an easy and inexpensive way to get position data from your project. The only tricky part is going to be deciding when and how to to zero out the location.

Not interested in this type of mouse hack? Can we spark your curiosity with this mouse auto-fire project?

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Broken Laptop Recovered Using An Arduino

January 4, 2011 by Mike Szczys 64 Comments

We see Arduino boards used in a lot of projects but we’ve never thought of using one as a USB crossover cable. That’s basically what [Jack the Vendicator] did to get his broken laptop running. When his video card stopped working he found himself unable to access the laptop. Newer machines don’t have a serial connector, which could have been used for a serial terminal, so he was at a bit of a loss since neither SSH nor VNC were installed. But he thought he might be able to use the Arduino as a serial terminal connector over USB. He plugged the Arduino into the laptop, and connected a USB serial converter from his desktop computer to the Arduino’s serial pins. In effect he’s just taking advantage of the FTDI chip, translating those signals back into USB on either end. Once he booted the headless laptop it took just a couple of blindly typed commands to get SSH running in order to regain control.