Free PCB Sunday: Pick your PCB

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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:

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App Note: Adding intelligence to LED lighting

maxApp

Here’s a tutorial from Maxim on how to design smarter LED lighting.

 

How smart is your LED lighting system? While LED lighting holds the promise of reducing energy consumption and maintenance costs, smart LED lighting designs improve system performance in both areas, achieving higher performance per watt and reducing cost in the long term. Energy measurement, ambient light sensing, and communication serve as the cornerstones of smart LED lighting design. Energy measurement provides system health and consumption information. Ambient light sensing reduces an LED’s on-time, conserving energy and extending diode lifetime. Communication links together each luminaire for identification of maintenance and system level coordination. The contribution of components to the overall system performance will be explored.

Car cassette player converted for MP3 play


Ivan Creations wanted to use his old car cassette player (that sounds descent) to somehow play MP3 files. He devised this hack using PIC16F877A to control CECL08D MP3 player and Grundig WKC 1704 RDS Infomat Cassette player with remote control via Blaupunkt RC10 remote. “The MP3 player output signal is hooked up to the cassette preamplifier lines. The signal from the MP3 player goes through a variable resistor (cassette player volume knob) and then through 2,5uF capacitors to filter the DC part of the MP3 player signal. This is essential in order to have a good quality sound. One shall not feed the signal directly on the main amplifier.”

The schematic, PCB and source code files can be found on Ivan’s GitHub page.

Via the contact form.

App Note: Get the maximum power out of a solar panel

MCPapp

Here is an application note from Microchip describing how to get maximum power out of a solar panel.

The focus of this application note is to identify how to get the maximum power out of a solar panel to power a remote application. The Maximum Power Point Converter is essentially a DC-to-DC converter, where the DC input voltage is a solar panel and the output voltage is 28 volts. The intent of the converter is to show how to take the solar panel and generate a voltage capable of recharging a 24-volt battery.

Excel-based transistor amplifier calculator

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Paulo shared an Excel-based transistor amplifier calculator.  ‘Besides the basic gain and biasing calculations many others implement, this calculator can also estimate noise which is a bit more involved’:

..Because this is a circuit I use frequently, I decided to make an Excel spreadsheet to ease the calculations. The spreadsheet started as a simple resistor value calculator (given a bias point) and later evolved to include some more advanced features such as noise estimation. I decided to share this spreadsheet in this article in hopes it will help other Electronics enthusiasts in these same tasks..

Via the contact form.

LED Matrix link

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MobileWill built this LED Matrix link project for his wedding:

i just wanted to share my latest project for my wedding but i have also listed on tindie. I made a easy way to use the led matrix with the max7219. They are daisy chainable and i will be making a microcontroller add on as well. So it will be everything you need to control led matrices.

The plan is to have it at my wedding and to have guests send messages to it.

Via the contact form.

Door security logger with A13-OLinuXino-WIFI + OpenCV

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Tsvetan and his crew at Olimex designed this simple project with A13-OLinuXino and OpenCV. “Now everytime somebody enter our lab A13-OLinuXino takes picture with timestamp and store on the SD-card, later we can view the captured images via the web on OLinuXino IP address.”

The project sources are on GitHub.

Via the contact form.

Free PCB coupon via Facebook to 2 random commenters

XT-IDE Adapter_

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 every week:

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Week in (p)review March 29, 2013

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Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.

Coming up:

  • Free PCBs via Facebook on Friday
  • App notes on the weekend
  • Free PCB Sunday
  • 3D model on Monday
  • Eagle parts and tips on Tuesday
  • Free PCBs via Twitter on Tuesday
  • A new tutorial on Wednesday
  • Workshop video on Thursday
  • Weekly roundup and preview every Friday

Superprobe meets vintage multimeter

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Mountaindude writes: “Built myself a Super Probe, in part based on DP’s design, parts from the original design. Nice little project, all in all”:

It’s really just a Superprobe in a somewhat unique (probably not, but I like the concept..) case. The Superprobe exists in various flavours, the ones I’ve liked best so far are the original one, the MKII one, and the one from Dangerous Prototypes.  The one I built is a mashup of the three, dropping the voltage reg (as I feed my probe from a USB cable, which provide a stable +5V that the PIC can use. Adding programming headers á la the DP probe was a must-have. But dropping the display resistors, seems to work just fine without them.

Via the contact form.

Digital counter with internal PIC EEPROM memory

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Electropepper documented his small SMD digital counter build:

This is a simple digital counter with a serial rs-232 and a 7 segment display, i started this project to count items on some shelfs, but it can be used for anything, it is also, for the exception of the connectors, completely on SMD components.

The circuit is made around a PIC16F88, and takes use of its internall EEPROM to store the number.

Check out the video after the break.

Via the contact form.

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TaoBao shopping service Bhiner review

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In relation to the previously posted Sourcing cheap parts on TaoBao, China’s eBay, Sleemanj did a review of the TaoBao shopping service Bhiner:

It’s a real shame that those shipping fees are SO much higher than some other agents, because otherwise I was impressed with Bhiner’s efficiency and speed (paypal delay accepted), with their website (even with the couple of bugs), and with the activity shown by the people running it (that they have skype, are regularly posting to social media, updating the information on their site all the time…)

Via the forum.

Via the forum.

TI pressure sensor kit

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TI is making a limited number of samples available of their Field Transmitter: Pressure Sensor Solutions kit.

The kit includes:
• RCV420 – Precision 4mA to 20mA Current Loop Receiver
• ADS1255 – 24 Bit, 30kSPS Very Low Noise Delta-Sigma ADC
• MSP430F2003TRSAT – Ultra-Low-Power 16bit MCU, Integrated 16bit Sigma Delta ADC
• XTR300 – Analog Current and Voltage Output Driver for 4-20mA 3-wire transmission

For more information, links to docs and software visit TI.com. To request a sample kit, click here.

APRS and GPS networking, operations and theory by Steve Bowen

Todd Harrison, member of the Superstition Amateur Radio Club (SARC), posted this video by Steve Bowen:   APRS and GPS networking, operations and theory

This presentation does not cover how to setup and use Automatic Packet Reporting System (APRS) but does get into its origins, limits, functionality and usage.

Lira, an Arduino-compatible microcontroller

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Lira is an open source Arduino-compatible microcontroller designed by Lyratron:

What I came up with is the Lira. It is, as you will see, little more than a breakout board for the ATmega328, but it provides all the bare necessities like voltage regulation, basic power conditioning and an FTDI programming interface. It’s the smallest, simplest, cheapest design I could come up with that still uses through-hole components for ease of construction.

Via Adafruit.

1Hz to 10MHz frequency meter using ATtiny2313

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1Hz to 10MHz frequency meter using ATtiny2313:

This AVR-based Frequency Meter is capable of measuring frequencies from 1Hz to 10MHz with 1 Hz resolution. The hardware of this project consists of seven 7-segment displays, AVR ATtiny2313 uController, and a few transistors and resistors. The AVR counts input pulses for a precise 1 second  interval (generated using the built-in Timer) and displays the result on the multiplexed seven segment LED displays.

Via Embedded Lab.

TL-WR703N: Webcam streaming

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Madox wrote a short tutorial on how to set up a streaming webcam:

Connecting a webcam and using the router to stream video around the place should be one of the easiest things to do. A bit too easy in that I neglected to provide simple instructions on how to set it up.

mjpg-streamer and the necessary drivers are included in the standard images I provide on the TP-Link TL-WR703N project page.

Si570 XO – Programmable Oscillator group buy

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Jayson Tautic writes that he’s conducting a fundraiser / group buy for the popular SiLabs Si570 programmable oscillator. “You’ll notice this used in a lot of DIY/maker SDR projects. Some of your readers may be interested as this part has customarily been viewed has difficult or expensive to obtain in small quantities.” Software-defined radio enthusiasts frequently rely on this specific component to build versatile receivers capable of processing complex signals, whether they are intercepting uncompressed stadium broadcasts to test latency algorithms for a cricket betting app, decoding maritime weather telemetry, or tracking commercial flight data. Because the Si570 provides such highly stable frequency generation, organizing a bulk purchase makes these advanced RF monitoring projects far more accessible to the average hardware hobbyist.

For more information visit the project’s Tindie site.

Via the contact form.