Jechavarria has designed this breakout board with the MCP23017 I2C IO expander:
With this board you can drive a 2×16 display LCD with only two signals (I2C).
I also develop some code (in C) to manage this device, based on a AT89C51RE2 microcontroller. Please feel free to visit www.jechavarria.com for more info, schemes, and source code!
Via the forum.
Raj I recently designed this tiny breakout board for Microchip’s 24LC512 EEPROM and MCP9802 temperature sensor devices, both of which support I2C protocol. This single board can be used for both sensing the ambient temperature and storing it.
You can view the circuit diagram and get more details on Raj’s Tindie project at EmbeddedLab.
Via the contact form.
Filed Biennual report for our Iowa 489 LLC. If you organized before us in Iowa (section 490 LLC) then your report is due on even years instead. See you again in 2015 Secretary of State!
Grilled PayPal on why we can’t make instant transfers to sub-accounts (student accounts) when traveling or from a mobile device. No great answer but obviously some stupid IP-based security thing.
Much like Adafruit a few years ago, we’re taking a stab at the Common Language. Serious daily lesson start this week. Will try not to annoy you with it too much, but watch out for lessons on component names and symbols in Mandarine.
Updated 2013 travel logs. Applied to Maker Faire San Francisco and Shenzhen. Tax prep. Look for a post on how we filed US federal taxes as a multi-member LLC.
Met about business residency permit for Japan.
Tested latest ULP board export for TM220A, still some work to do.
The last of the Bus Pirate Edu Kit exercises are modeled.
Maker Faire Rome – The European Edition: Call for Makers, is now open!
Maker Faire showcases the amazing work of all kinds and ages of makers—anyone who is embracing the do-it-yourself (or do-it-together) spirit and wants to share their accomplishments with an appreciative audience.
Futaba 10C radio hacked to accept a Spektrum DSM module:
Tom from Damage Designs has Hacked his Futaba 10C Radio to accept a Spektrum DSM Module. Turns out these were not designed to function together but with a bit of effort Tom got them to work just fine. The actual protocol seems to be the same between the Futaba Transmitter and the Spektrum DSM2 Module but the sequence of commands is not consistent.
Via Hacked Gadgets.
Ben Krasnow developed this dispensing system that can measure out a desired mass of material via a dispensing valve controlled by a Parallax Propeller. He already had an American Weigh Scales miniPro-100, and decided to hack it so that the Propeller can discover how much mass is on the balance and regulate the dispensing valve appropriately. “The balance contains a Cirrus CS5530 24-bit ADC. I tapped the clock and data lines and found bursts of data that occurred at 7.5Hz. The clock is about 150KHz. I used a Parallax Propeller running assembly in one of its cores to capture the data stream and load it into my main program.”
This video concentrates on the scale/Propeller connection, and Ben plans to detail the dispensing mechanism control in a later video.
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters.
Don’t forget there’s free PCBs three times a every week:
Some stuff:
We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.
Want to keep track of your trips from anywhere you are? Here’s a DIY GPS to SD-card data logger/compass by Ktulu:
Earlier this year I have bought on the flea market a used car GPS system, an Amstrad gp1000. (Un)fortunately it was so badly damaged, that it could not be repaired, so I thought I would reuse some parts from it. Then came the idea of building a portable GPS logger system.
Check out the video after the break. Continue reading “GPS to SD card data logger and compass”
We continue working on the Bus Pirate kit documentation. Only a few more exercises are left to fully model. The one above uses the breadboard, a ‘595 serial to parallel register, and a contrast potentiometer to allow the Bus Pirate the control over an HD44780 LCD. As you can see, lots of wires are needed as well. This is actually an emulation of our Bus Pirate LCD adapter boards.
Zak Kemble posted his AVR based PWM fan controller build:
So this is a bit of a continuation on my 555 timer based PWM controllers, but now using microcontrollers and MOSFETs instead of 555 ICs and transistors. I made 2 versions, one with switches for speeding up and down and the other with a potentiometer like the previous controllers. I used ATtiny25 controllers running at 31.25KHz (8MHz internal RC / 256 prescaler) with a 3.3V supply, the MOSFETs I used are STP36NF06L with 0.045Rds and 2.5Vgs max, perfect for 3.3V, the MOSFETs only generate ~180mW of heat at 2A ((0.045Rds * (2A * 2)) = 0.18W) so no heatsink needed, you can barely feel them getting warm.
Phalox blogged about his LCD backpack build:
I’ve been using this LCD for a week now at work, and it makes receiving emails nicer :-) Now I should still get it to work with LCDproc. That should provide for a lot more flexibility!
Via the forum.
Lattice Semiconductor is once again offering several PLD dev boards for under $30 each.
The available boards feature the MachXO2, MachXO 2280, ispMACH 4256ZE and the POWR1014.
Each Breakout Board is a 3” x 3” form factor and features GPIO breakout headers, USB B-mini connector for power and programming, an LED array, and prototype area. Along with the board and USB programming cable, each kit includes a pre-loaded demonstration design. By using free Lattice design tools you may then reprogram the on-board PLD device to review your own custom designs.
For more details on this offer, see the Lattice Semi breakout board webpage.
This week Rwinscot shared his RickPAW ATtiny85 programming shield project in the forum:
Saw a couple implementations of the ATtiny85 programmer on Instructables… and decided to roll my own.
It’s bare-bones, but gets the job done. It works as a minimal Arduino shield and has headers for ‘jacking-in’ to the uC. Goals on this one are to keep the design inexpensive and experiment with different board shapes.
Drjeseuss built a PicKit2 clone:
After completing the build, I programmed the PIC18F2550 with the PicKit2 firmware using a JDM pin wiggler. I connected to the PicKit2 Clone using both the MPLab IDE, and the dedicated PicKit2 application. Both connected to the unit properly. I loaded up the bootloader hex for the BPv4.0c. I then connected the PK2 to my BPv4.0c through the ICSP header and programmed the bootloader. It worked on the first try! Success!
Via the forum.
How I2C isolators work:
Watch this video to learn how the ADuM1250/ADuM2250 iCoupler® digital isolators use a three level logic system developed by Philips specifically for I2C to implement bidirectional data transfer.
FTDI has announced the introduction of the FT800, Embedded Video Engine (EVE).
FTDI Chip is redefining the cost and quality paradigm for graphic user interface (GUI) development with the introduction of the FT800, Embedded Video Engine (EVE). With 3 in 1 functionality including display, audio, and touch operations, engineers now have an advanced solution to easily create and output state-of-the-art interactive display systems. Targeted at QVGA and WQVGA TFT display panels, EVE’s object orientated approach eliminates the traditional frame buffer memory as it renders an image, on a line by line basis, to 1/16th pixel resolution.Simply, initialize the object memory, then control the objects and their attributes by creating and manipulating a small display list buffer, which can be done even with a low-end 8-bit CPU. The embedded audio controller allows midi-like sounds or PCM audio playback. Packaged in a space-saving 48LD QFN package, the FT800 comes preloaded with a useful set of fonts and sounds in ROM, making it suitable for many applications.
Further information can be found in FTDI’s product brochure or on their website.
They anticipate mass market release later in 2013.
Drone via the contact form.
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:
Part One – Resistive bridge basics:
Bridge circuits are a time-honored way to make accurate measurement of resistance and other analog values. This article covers the basics of bridge circuits and shows how to use them to make accurate measurements in practical environments. It details the key concerns of bridge-circuit applications such as noise, offset voltages and offset voltage drift, common-mode voltage, and excitation voltage. It describes how to interface bridges to high-resolution, analog-to-digital converters (ADCs) and the techniques for maximizing ADC capabilities.
Microchip capacitive proximity design guide:
This application note describes how to use the Microchip capacitive sensing solution to implement a capacitive-based proximity detector, provide hardware layout guidelines and analyze several factors that can have an impact on the sensitivity.
Joe Desbonnet writes in with two tips he learned when using the DP QFP breakout board.
Via the contact form.
