Visualizing PCB Revisions Using A Gerber Viewer

gerber_schematic_highlighting

We all know that Eagle has its share of shortcomings. Instructables user [westfw] was particularly annoyed by the fact that while Eagle keeps copies of up to 10 revisions of your board, it cannot open those files without resorting to manually renaming each one. Even more frustrating to him is the fact that you can’t use Eagle to view two files simultaneously in order to compare layouts. This made hunting down changes quite tedious, so he started looking for a better way to do things.

While using his favorite open-source gerber viewer gerbv, he noticed that the application let him load multiple copies of the same layer, XORing the PCBs’ colors together. Realizing that with some clever color selection, he could use gerbv to automatically highlight layout differences, he set off to automate the process.

The resulting script works on any flavor of *nix, and should play nice in Windows under cygwin as well. The script reads through Eagle backup files, renaming them and tweaking the colors so that when XORed, they show up as bright red areas in gerbv. It’s a simple yet handy tool to have on hand if you happen to do a lot of PCB design.

Want To Play Pong On Your Oscilloscope?

I always have! I don’t know why, but I like the idea of using an oscilloscope screen as a general use video display. Why not? In my case it sits on my desk full time, has a large screen area, can do multiple modes of display, and is very easy control.
Making an oscilloscope screen do your bidding is an old trick. There are numerous examples out there. Its not a finished project yet, so be nice. It is actually rather crude, using a couple parts I had on hand just on a whim. The code is a nice mixture of ArduincoreGCCish (I am sorry, still learning), and includes the following demos:

  1. Simple low resolution dot drawing
  2. A font example
  3. A very quickly and badly written demo of pong

The software runs on an Attiny84 micro controller clocked at 16Mhz, paired up with a Microchip MCP42100 dual 100k 8 bit digital potentiometer though the Attiny’s USI (Universal Serial Interface) pins. This is a fast, stable and accurate arrangement, but it requires sending 16 bits every time you want to change the value of one of the potentiometers so its also very piggy. I was just out to have some fun and did not have a proper 8 bit DAC. This was the closest thing outside of building one.
Join us after the break for pictures a (very) brief video and more.

Continue reading “Want To Play Pong On Your Oscilloscope?”

Making The Case For In-circuit Debugging Tools

in_circuit_debugging_of_pic_microcontrollers

If you are in the market for a PIC microcontroller programmer, you may want to consider a model with an In-Circuit Debugger (ICD). [Rajendra] put together a great tutorial on using an ICD when debugging PIC firmware, which makes a pretty convincing argument for owning one.

In his tutorial, he happens to be using a MikroElektronika PICflash2, but he says that there are plenty of other ICDs out there if you are not keen on this particular model. The PICflash2 not only acts as an ICD, but as the name suggests it works as an ICSP as well.

[Rajendra] walks us through a short debugging session using some simple code that reads data from an LM34DZ temperature sensor, displaying the results on an LCD screen. While he isn’t actually hunting for bugs, he does show how easy it is to step through the PIC’s code one statement at a time, evaluating variables and registers along the way.

[Rajendra] does point out that using an ICD does occupy a few I/O pins while running, limiting your resources just a bit. We think that being able to debug code as it runs is pretty reasonable tradeoff if you don’t necessarily need each and every pin available for use.

Adding Auto-off To A Cheap Multimeter

[Florin] picked up a cheap multimeter in order to make multiple measurements at one time. Unfortunately, he wasn’t very good at remembering to turn it off when he was finished so he burned through some batteries. Why an auto-off feature wasn’t the first thing coded into the firmware we’ll never know, but [Florin] developed his own hardware-based auto-off circuit.

It sounds like he had all of the components necessary for this on hand already. He grabbed an AVR ATtiny25 in a surface mount package. To keep the board small, he didn’t include an ISP header, but instead made long pads that could have wires soldered to them for flashing the firmware. The microcontroller drives an NPN transistor that can cut off the ground path between the multimeter and its battery. A tactile switch is connected to one of the external interrupt pins and, when pressed, gives you 15 minutes of time to use the meter. After that, the chip kills the power and goes into sleep mode. Simple, and small enough to fit inside the case.

[via Dangerous Prototypes]

CircuitBee Makes Sharing Schematics And Circuit Diagrams Easy

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When looking for things to write about, there is nothing we like to see more than well-documented schematics and code available for download. In the case of schematics, we realize that they can be a bit of a pain to publish. Many times we see them in the form of blurry JPEGs or humungous PDF files, neither of which are incredibly convenient to use. The folks over at CircuitBee thought the same thing, and have been working diligently to make it easier for everyone to share their awesome ideas with the world.

Their free service requires registration, and not much else. Once you’re in, you are free to upload your Eagle or KiCAD circuit diagrams, which are then run through CircuitBee’s servers. They convert your drawings into embeddable objects which allow others to view your project without a lot of fuss. Their embeddable schematic window can be rendered in full screen mode, and gives users the ability to zoom in on any portion of the drawing to see the circuit’s finer details.

[Ben Delarre] from CircuitBee says that the product is in the alpha stages right now, so there are plenty of features and useful tools coming in the near future. If you like to build and share, it’s definitely something worth checking out!

[via Make]

[Thanks, Sanchoooo]

Component Storage Roundup

It’s been suggested that the first self-replicating computer virus was a single IC that eventually expanded into multiple plastic component storage boxes. Organizing components by their values is a huge PITA as well. Here’s some solutions we’ve found:

Photo Boxes

[Mathew] sent in his organization scheme that uses 4×6 photo boxes. Better get those boxes while they’re hot – we can’t remember the last time we used film.

Use a binder

This instructables uses binders for storage. Good for passives, but unless someone can find anti-static bags for a binder, we’ll keep our ICs separate.

The only way to organize resistors

[Johannes] stores his resistors on a sheet of styrofoam. The grid has the first color band on the left side and the second color band on the top. Extremely, extremely clever. We’re wondering why we Radio Shack didn’t come up with this in the 70s. The grid could be laid out on a log scale, though.

If Susan is lazy, why does she do all the work?

[D.C. Boyce] hacked up a couple of lazy susans, built frames out of 2x4s and mounted plastic component drawers on them. The result is probably more space than we’ll ever need. To keep things simple, he wrote a database program to keep track of everything.

Adding USB Connectivity To Old Benchtop Tools

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[Scott] was recently given a frequency counter, and once he brought it home, he started contemplating how he could possibly make it better. While the counter worked well as-is, he wanted to find a way to record data readings over a reasonably long period of time. He figured that interfacing it with his computer would be the best way to do this, but he had to find a way to connect the devices first.

He started poking around inside the frequency counter and stumbled upon a possible data source when taking a closer look at the display board. He found that he could read the frequency data as it was being written to the display, and send that data to his computer. He used an ATMega48 to intercept the data and code from the V-USB project to bit-bang the data to his PC over USB.

Now, anything he sees on the frequency counter can be easily collected and graphed on his computer with little fuss.

Stick around to see a quick video demonstration of his hack in action.

Continue reading “Adding USB Connectivity To Old Benchtop Tools”