A while ago we wrote about using cheap Nokia 1202 LCDs for projects. These LCDs come with a solderable connector, and are easy to interface over the I2C bus. Toxic239 made a frequency counter based on the MSP430 Launchpad and this LCD. Source code for his project is available in the forum.
Our latest 3D model is the PIC32F and PIC24F SOIC-28 breakout board . This project lets you get familiar with the PIC32 and PIC24 microcontrollers in a breadboard friendly “blade” style breakout board that leaves plenty of room for other parts.
Check out our tutorial on how to build 3D models from Cadsoft Eagle board files, as well as the tutorial on how to render life like images with Kerkythea.
The models will be published in the Dangerous Prototypes 3D warehouse collection. They are also uploaded to our SVN. You can find them inside the “art” folders in the respective project folders.
The 2012 GNU Radio Conference will be held September 24-27, 2012, at the Sheraton Gateway Hotel near the Altanta, GA airport. The conference coordinators have posted a “call for papers” from prospective presenters. Visit this link to fill out and submit the form with your idea for a presentation. The deadline for submission of abstracts is June 29, 2012.
Keep an eye on the conference website for more details.
Working with low pitch SMD components can be a pain on the eyes, and one way to make it more conferrable is to use head worn magnifying glasses. Arhi wrote an in depth comparison of the 3 models he had tried out so far. While none of them are ideal, the ones mounted on spectacle frames were the easiest to work with in his opinion.
Via the forum.
Jawi continues to develop the Logic Sniffer cross-platform client. A beta of the new version 0.9.6 is available to testers. This has the killer new signal display component demoed previously. Jawi’s open source client will soon outclass every commercial offering we’ve ever used. Here’s the change log:
- New signal display component is in place! While not yet as customizable as the previous one, it does provides the ability to DnD channels, have proper context menus, allow disabling/enabling channels and so on
- New way of measuring stuff in signals (see Tools menu): it allows you to count transitions, clock speed, duty cycle
- Added the ability to run a OLS over the network; this patch is initially provided by Marcin Zapolski (thanks for that!). I’ve not tested it in much detail, and needs an additional “server” for the OLS on the other side which is not yet provided
- Added a custom build of the used serial library to support baud rates higher than 115k2
- (more to come)…
Bugs and improvements, as always, can be entered through GitHub
Some IC packages have a large exposed pad on the bottom. It’s usually connected to the chips ground, and helps cool the chip by transferring heat to the PCB. This app note from Maxim describes the functionality of exposed pads, as well as their proper use.
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service.
This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB.
You get unlimited free PCBs now – finish one and we’ll send you another!
Don’t forget there’s free PCBs three times every week:
Here is an app note from Texas Instruments on how to power various systems required for portable media players. These devices require several different voltages, multiple power sources, as well as integrated battery charging. The article describes each individual section in detail.
Here’s an easy open source motion sensing project by Matt Williamson which sends you an SMS message when motion is detected. The hardware consists of an Arduino and Parallax PIR sensor (Part No. 555-28027). This arrangement communicates via serial with a Python server on an attached computer, which then uses the TelAPI service to accomplish the SMS transmission.
You can find the Arduino and Python source code and related docs on the project’s Github page.
Learn how to implement fixed current limiting in power-supply designs:
In every power supply application there exists the possibility to short the output to ground causing excessive current to be drawn from the power supply. In order to limit the output current from becoming excessive the following examples of current limiting circuits are suggested.
Texas Instruments’ advice for isolating digital and analog power supplies in mixed signal circuits.
This application note recommends power supply and ground noise-reduction techniques through the use of bypass capacitors and ferrite beads in TI’s PLL-based clock distribution circuits (CDC) devices. This application note also includes a numeric example, calculating the value of bypass and filter capacitors for a particular frequency of interest.
The article is written for PLL based clock distribution circuits, but the pointers can be applied to any mixed signal device.
Manuel Garbe and Drone both wrote in to draw our attention to this new “Lightning Detector” chip from Austriamicrosystems. According to the manufacturer’s press release, “[t]he AS3935 is a programmable Lightning Sensor IC that detects the presence and approach of potentially hazardous lightning activity in the vicinity. It detects intra-cloud activity as well as cloud to ground flashes, often enabling risk to be evaluated for approaching storms, while rejecting interference signals from common man-made sources such as: fluorescent lighting, motors, microwave oven, switches, etc. The flexible IC allows for configurability that allows the part to work both indoors as well as outdoors, just changing the gain setting in a register.”
You can find more information on the product’s info page.
In order to receive the datasheet and price information, the manufacturer requires that you complete their registration process.
Via the contact form.
You can use your Bus Pirate to read a Fastrax UPS501 GPS module. Since the module has a UART, just connect the RX and TX pins, and set the Bus Pirate for UART mode. The correct settings are UART, 9600 baud, 8bits, no parity, one stop bit, receive polarity 1, and a normal output type.
Get your own Bus Pirate for less than $40.
Via the forum.
Reading ambient temp is useful in electronics, and reading it from your handy multimeter is even better. Raj added a thermometer feature to his DMM, by hard-wiring it into the case. He used an LM35 analog temperature sensor and a slide switch connected to the multimeter inputs. You just flip the knob to the 200mV range and slide the switch to get the readout.
Via the forum.
DIY Audio function generator is a low-distortion function generator which operates in the Audio frequency range. Conventional function generators use a square wave signal to generate the other waveforms like triangle, or sine wave. This approach adds noise to the sine wave output, which is the one waveform Eric wants for his audio development.
His workaround is to reverse the process, or use a sine-wave signal to generate the other waveforms. This approach will generate a much cleaner sine-wave output while still having other waveforms as options.
Sine Wave Generator based on the #327 Lamp Wien-bridge Circuit to get the low THD. I’ll then feed that into a Comparator to produce the Square wave; I am then using the Square Wave to turn on/off a ramp generator circuit. I would rather have a ramp output vs a triangle wave. The ramp circuit will let me play around with different single & dual slope ADC concepts later on.
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday.
Don’t forget there’s free PCBs three times a every week:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Here’s a simple theremin-like device designed by Sacred and presented by Jameco. Unlike other theremins which vary the sound based on the user’s proximity to stationary antennae, this project uses two phototransistors and a 555 timer. The theory of operation is the variation of the sound based upon the amount of IR light reflected by the user’s hand. The article contains the schematic and BOM (conveniently keyed to Jameco part numbers, of course.)
Instructables via Jameco.
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.
Coming up:
What are you hacking this week?
DIY etched boards are the quickest way to get a project up and running. This is just what Noy did with his IR Toy, and CPLD breakout boards. He modified our projects to a single layer design. Used the toner-transfer method to copy the traces, and etched the boards with a mix of hydrochloride acid and hydrogen-peroxide.
Hey Guys,
I’m a student from Germany and I love this Blog. So a few weeks ago i tried my first etching example. So i needed a small circuit in single sided design. Because I wanted to etch a sensemaking curcuit not only an etching test, I decided to etch your IR-Toy and your CPLD Board. So I routed it to single sided and I did it with the direct toner transfer method. Everything worked great I was etching it with HCL+H2O2 (really fast!! but quite dangerous!!).
You can get IR Toy v2 for $22.05, including world wide shipping.
Get an assembled XC9572XL dev-board for $15 and CoolRunner-II development board for $15.
Via the forum.
Dpropicweb tipped us to a new Open source Bluetooth stack for PIC24 and PIC32. For hardware, a PIC drives a cheap USB Bluetooth dongle using a USB host interface. The Bluetooth part is open source, unfortunately is also uses Microchips undistributable USB drivers.
- The code is really easy to understand, very well documented and really small.
- Designed to be extended and ported.
- Works straight out of the box with the PIC32 USB Starter Kit II and should be fairly simple to port to other PIC32 or PIC24 boards.
