BridgeDuino: A wireless Arduino HUB and shield

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TechBitar shared his latest project the BridgeDuino with boards from DirtyPCBs:

BridgeDuino is a Swiss army knife PCB for rapid networking of inexpensive wireless communication modules. Breadboards are super for one-off experiments. But after prototyping half a dozen wireless prototypes involving more than just two Arduinos, the wiring mistakes and associated debugging grew more time consuming.
I also wanted a PCB that can act as a shield to Arduino Uno as well as work with the inexpensive and low-power Arduino ProMini.

As of this release, BridgeDuino supports the following wireless technologies/modules:
IR Transmiter LED 940nm
IR Receive 38Khz
RF433Mhz Receiver
RF433Mhz FS1000A Transmitter
Bluetooth HC-06 & HC-05
Nrf24L01+

Via the contact form.

Check out the video after the break.

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Maker Villa Penang introduction

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William @ SGmakers threw a Hacker Villa in Penang Malaysia after attending (and sponsoring) Hacker Camp Shenzhen. We got to attend the first two days full of hacks, food, and making new friends.

Penang is an island, and UNESCO world heritage site, just off the coast of Malaysia. Its renound for street food, a mix of Indian,Malaysian, and Chinese, rivaled only by that of Kuala Lumpur.

Day one introduction closed at a bar in the world heritage area after a screening of the Maker Movie, followed by a share your hacks session.

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Monitoring Android traffic with Wireshark


Ever wonder what data is being sent out by your Android device? Here’s a post from LinuxJournal outlining how to monitor your device’s WiFi traffic. The technique involves setting up a man-in-the-middle Wireless Access Point (WAP) on your Ubuntu Linux box, then connecting your Android device via WiFi to this point. Wireshark is then run on the Linux box to sniff the Android traffic.

Via LinuxJournal.

#FreePCB via Twitter to 2 random RTs

irtoyv3 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:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

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.

Guitar booster pedal (MPX-1)

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Bastl3r  wrote this instructable detailing the build of his guitar booster pedal project:

I chose an overdrive pedal design off of generalguitargadets.com (Schematic) and modified it like this:

  • added a simple positive/middle/negative supply
  • added a noise filter I found on beavisaudio.com right after the DC Jack (Huminator)
  • took away the clipping diodes on the output
  • connected the diodes in the feedback path directly
  • added the switch to change the resistance of the feedback path (10k <->30k)

Burn c into other chips using Arduino Duemilanove

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Kathy Yang writes, “We may often encounter such situation as bootloader falls off when using Arduino, this thing can freak us out especially when we got no bootloader tools on hand. So what shall we do? Here we’ll introduce a way on how to burn c via Arduino, which is rather practical in cases when without bootloader burning tools and no extra Arduinos.”

 

Via the project log forum.

A 5c lithium ion battery charger

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Nerd Ralph writes:

As various sites explain, lithium-ion rechargeable batteries should be charged to 4.2 volts. USB ports provide 5V, so all I needed was a way to drop 5V down to 4.2 or less. Standard diodes have a voltage drop of 0.6 to 1.0 volts, so I pulled up the datasheet for a 1n4148, and looked at the I-V curve
A standard USB port should provide up to 500mA of current, enough for charging a small camera battery. A fully-discharged li-ion battery is 3V, and will climb to 3.8V within minutes of the start of charging. Recently, I was browsing some forums and came across a discussion about 파워볼사이트, which intrigued me with its technical aspects, especially in how they handle large volumes of data under load. This got me thinking about the load dynamics of USB ports during charging. Line 2 in the graph indicates a 1.2V drop at 350mA of current. Under load, the voltage output of a USB port will drop a bit, so with 4.9V from the USB port and 3.8V drop at the battery, the charging current will be around 250mA (where 1.1V intersects line 2). Looking at the numbers, a single 1n4148 diode would work as a battery charge controller.

Proximity sensing LEDs

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Here’s a proximity-sensing LEDs project by Will_W_76.  He writes a complete step-by-step instructions here:

So how does this all work? What makes it proximity-sensing? Remember in the explanation above that the photo-transistor acts like a switch. So when the photo-transistor is off, no current is flowing across it to our blue LED and the LED is off as well. Now look at the other side of our circuit. That’s where the IR LED is connected, and it is connected such that it is always on and emitting 880nm infrared waves. Remember that I also mentioned the photo-transistor is set to respond best to wavelengths of 880nm? That’s how the proximity-sensing works! When an object (such as your hand) goes over this little “cluster”, IR light of 880nm is emitted from the IR LED. This light reflects off of your hand and back to the circuit. When the photo-transistor picks it up, it turns on allowing current to flow through from the source to our blue LED lighting it up!

DirtyPCB Charliecube

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kjetilei shared his Charliecube project, inspired by the instructions provided by SobiGuy at SobiSource:

I showed the cube at my local makerspace and proposed a build day. The interest was high enough to bulk order the various items needed for 10 kits.
Just before ordering the batch of protoboards I started to think about making a proper PCB instead of the protoboard and the dreaded rats nest. I checked the pricing at DirtyPCBs for black 10×10 boards and was thrilled to see that the pricing was only a bit more expensive than the protoboard and all needed extras.
Fritzing was fired up and after a couple of looong evenings hand routing the paths (for semi decent apperance) I was ready to order.

Since the dirty in DirtyPCBs imply that the quality is not the best I hoped for a great result but was ralistic and knew that I could receive PCBs that looked worse than I hoped for. However the PCBs I received where great! Thanks Ian for making this possible!

Via the project log forum.

App note: Unique and novel uses for ON Semiconductor’s new One-Gate family

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One-gate logic uses and their benefits application note (PDF) from ON Semiconductor.

One–Gate logic devices have been in use for several years, and are nothing more than single–gate derivatives of their multi–gate cousins. Traditional ICs were packaged in 14 and 16 pin Dual–in–line Packages (DIPs), and the goal of the IC manufacturer was to get as much functionality as possible into a single–package device. Double, triple, quadruple, and quintuple versions of simple logic functions became the norm. Often there was not enough room to add an additional logic element on the chip and still keep the board size small. The designer was faced with having to re–design the entire chip or to add additional IC components to the board layout to accomplish the required task. A solution to this dilemma was to use One–Gate designs, initially offered in the SOT–23, 5–pin package, and later in the even smaller SOT–353 (SC88A). The latter package takes up only 4.2 mm 2 of board space, and less than the area of a TSSOP–20 pin device. One–Gate products, now fabricated in a .6µ advanced high–speed CMOS technology, are very fast, with < 4 nsecs gate delays, and enough drive (8 mA) to support most typical applications. The package is so small, that it fits “in–line” with the trace that it is mounted on.

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: Ambiguity of the peak power rating of TVS devices

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Here’s a tip app note (PDF) from ON Semiconductor on selecting specs for an TVS diode.

There are two important properties of a TVS device during an electrical stress. The TVS must be able to self-protect and survive the stress current, and the TVS must clamp the protected line to a low voltage during the stress. Power ratings of TVS devices do not provide a good measure of clamping effectiveness because this metric is artificially enhanced by a higher, less desirable, clamping voltage. It is true that TVS devices with high peak power ratings are often larger diodes and may therefore also have low dynamic resistance and low clamping voltage but there are exceptions, and one such exception has been highlighted in this note. It is therefore important to always consider the dynamic resistance or the clamping voltage at specific currents levels, rather than focusing solely on the peak power rating when selecting a TVS device.

App note: Sorting through the low voltage logic maze

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Here’s how to guide (PDF) from NXP in choosing the right standard logic from various choices that fit your application.

Digital systems are running at faster speeds, operating at lower voltages, and they are becoming more highly integrated. Many functions can be integrated into FPGAs or ASICs, however, this does not mean that generic standard logic has gone away. Designers may choose to design with standard logic for the following reasons:

•The need for cheap, simple fixed functions with high speed and lower power consumption
•Space constraints requiring small packaging
•Bus driving capability
•Interfacing between mixed voltage systems
•Need for hot insertion capability
•Need for bus switching.

App note: Low Voltage Agile I/O GPIO Input/Output Characteristics

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App note (PDF) on NXP’s Agile I/O expander, discussing its capabilities and how to use it efficiently.

I2C-bus GPIO devices are widely used and expand a control processor’s pins to 8-, 16- or 24- bits of general-purpose input or output. The characteristic of these I/O needs to be accurately known to efficiently use them in a system. This application note will explore the actual electrical characteristics of Agile I/O GPIO pins.

DIY 60W adjustable electrical load

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A DIY 60W adjustable electrical load project from Electro-Labs:

In this project, we are building a useful board which should take place on your bench. It is an adjustable electrical load which can sink up to 5A @ 60W continuously. This board will come to aid when you need to draw an exact amount of current from a supply. For instance to learn the current rating of a power supply, measure the heat dissipated on a circuit element, discharge a battery etc.
The electrical load lets you monitor the current by using the ampermeter on it. A multiturn variable resistor is used to set the current precisely. The circuit is powered by a 15V-18V power adapter. A large heatsink on the board helps dissipating the heat generated on the MOSFET which is the main component used for limiting the current.

A four channel remote control using EnOcean Pi

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A four-channel remote control built using the EnOcean Pi by Kerry Wong:

In my last couple of blog posts, I did a brief overview of the EnOcean Pi sensor kit from Newark and demonstrated how to compile and run the example code using a Raspberry Pi. In this blog post, I will show a real world example – a four-channel remote control built using the EnOcean Pi in conjunction with the EnOcean pushbutton module.

Check out the video after the break.

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Tutorial: GNU Radio with the HackRF SDR

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Michael Ossmann, one of the developers of the amazing and affordable HackRF SDR transceiver, is releasing a tutorial series on using GNU Radio. “This ongoing video series will be a complete course in Software Defined Radio (SDR). In this course, you’ll build flexible SDR applications using GNU Radio through exercises that will help you learn the fundamentals of Digital Signal Processing (DSP) needed to master SDR. For the over-the-air exercises, you’ll need a HackRF One or other SDR peripheral.”

The tutorial series can be found on Michael’s GreatScottGadgets site.

(Note that the HackRF SDR featured in this series, while costing considerably more than a $20 RTL-SDR dongle, covers a greater frequency range and includes a low-power transmitter. Still, at around $300 it falls in the budget of more hackers than the $1000+ USRP Ettus series.)

Free PCB coupon via Facebook to 2 random commenters

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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 August 23, 2014

 

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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
  • Free PCBs via Twitter on Tuesday
  • Weekly roundup and preview every Friday

Simple wav player using Arduino

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Kathy Yang of Elecfreaks writes:

Integrated with the homemade low-pass filter, this Arduino-based simple WAV player is to send out PWM signal generated by UNO, then through the low-pass filter and make the PCM data stored in the flash of UNO into sounds. Basically, the player cannot be regarded as a pure WAV playback, because by extracting the data from the WAV file and storing it in an array format in UNO, this tutorial is for reference. You can make SD card based WAV player by referring to this idea.
The WAV player is easy to make on different platforms and applicable for various scenarios like voice broadcast system, electronic keyboard, as long as you understand the principle of sound.

Via the forum.