App note: Analog switches solve many problems within a cell phone

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Applications(PDF) of analog switches inside a cell phone by ON Semiconductor.

Analog switches have been available since the 60’s as a component for systems designers. With the advent of ASICs and ASSPs, many designers have not experienced the real value of these devices. Today’s designers may be familiar with the venerable MC14066, a workhorse that has been around for 30 years or more. The device consists of 4 independent switches that provide bilateral capabilities when “ON” and nearly infinite impedance when “OFF”.

Enter the single gate solution: On Semiconductor now offers a low voltage, single version of the 4066 in a one gate package. The MC74VHC1G66DFT2 is a single switch (SPST) occupying less than 4.5 mm 2 package, specified from 2.0-5.5 V and offers < 25 ohms resistance when turned “ON” and almost infinite impedance when turned off. Interestingly, the device can pass/stop either a digital or analog signal. Digital signals get passed with <1.0 ns delay, and very nearly no change in the signal. Analog signals get passed with less than 0.1% distortion and the device has a –3.0 dB point of >100 MHz. Several more devices were added to the portfolio including SPST, SPDT, dual SPST, DPDT, 2:1 Mux, dual DPDT functions. These are all available in tiny packages from 2.1 x 2.0 mm to 3.0 x 3.0 mm.

App note: Li-Ion/Polymer Shunt battery charger system with low battery disconnect

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Li-Ion/Polymer Shunt battery charger system with low battery disconnect (PDF!) app note from Linear Technology:

The LTC®4071 allows simple charging of Li-Ion/Polymer batteries from very low current, intermittent or continuous charging sources. A near zero current low battery latching disconnect function protects even the lowest capacity batteries from deep discharge and potentially irreparable damage. The 550nA to 50mA operating current makes charging possible from previously unusable sources. With its low operating current the LTC4071 is well suited to charge low capacity Li Ion or thin film batteries in energy harvesting applications. The unique architecture of the LTC4071 allows for an extremely simple battery charger solution, requiring just one external resistor.

App note: 1-Wire communication with PIC microcontroller

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An application note (PDF!) from Microchip on 1-Wire communication with PIC microcontroller:

This application note introduces the user to the 1-Wire® communication protocol and describes how a 1-Wire device can be interfaced to the PIC® microcontrollers.
1-Wire protocol is a registered trade mark of Maxim/Dallas Semiconductor.
A software stack for the basic, standard speed, 1-Wire master communication is provided with this application note along with an example application

Flir Lepton thermal imaging sensor + gameduino 2

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Andrew Rossignol of The Resistor Network writes:

I have successfully implemented a driver for the Lepton module and displayed frames on an LCD. This is all running on an STM32F4 processor on a Nucleo board. Attached to it is a Gameduino 2 which incorporates the FT800 graphics processor. I have implemented my own colorization and min/max scaling before uploading the frames to the GPU.
I have used some simple jumper wires to interface with this camera. This setup is running at 21MHz with no issues. I am using a breakout board provided by Pure Engineering. You can pick up one from Tindie if you are interested. The Lepton module can be ripped out the Flir One iPhone accessory for now.
I wrote my own driver for the Lepton core and the FT800 graphics processor.

For more details visit Andrew’s website.

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.  The coupon code usually go to Facebook ‘Other’ Messages Folder .  More PCBs via Twitter on Tuesday and the blog every Sunday.

Don’t forget there’s free PCBs three times every week:

Continue reading “Free PCB coupon via Facebook to 2 random commenters”

On Western Digital hard drives, PUIS and Rocket Raid controllers

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Peter Hofmann fixed his drives and documented the whole process on his blog:

After about a day of trial and error, I finally fixed my drives. To save anyone else the days worth of effort, I’ve documented my solution here:

Firstly you need to go and find a tool called HDAT2 from www.hdat2.com download it and create a boot disk for it.
Then a tool called MHDD is needed but you need to inject the bootable ISO with some script files from the above hddguru address. Problem is, this is quite difficult and requires a floppy drive, or a virtual floppy drive which turns out is quite difficult to use on a 64 bit machine. Virtualbox and 32bit windows XP to the rescue. After a fair bit of futzing around I finally ended up with a final ISO file that can be burned and booted – the hddguru post doesn’t say exactly where one of the bin files needs to go so I had to guess around a bit before getting it right. Get the bootable ISO from here dl.dropboxusercontent.com
If you want to make your own, then just remember that PUIS goies in the scripts dir and off.bin goes into the dir above that

The Commodore 64 Flash Cart (C64FC) is done!

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The Commodore 64 Flash Cart (C64FC) project by Stian Soreng:

A few days ago I had a breakthrough getting the device to identify as an USB HID device, and yesterday it all just “clicked.” The device works and transfers images without a hint of problems. Release candidate 2, with its minor hardware patches, is perfect
Since the cartridge identifies as a HID device, no drivers are required! The client software automatically detects it on the USB bus and communicates with it. File transfers are so smooth and fast you have to see it for yourselves

Check out the video after the break.

Continue reading “The Commodore 64 Flash Cart (C64FC) is done!”

Single Cell Software frees Korg Volca Sample from iOS chains

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If you experiment with electronic music, you’ve probably heard of Korg’s latest addition to their Volca line known as the Volca Sample. The volca sample is a sample sequencer that lets you edit and sequence up to 100 sample sounds in real time. It lets you recreate the characteristics of the first generation of samplers, in which any sound including vocals, spoken words, ambient sound, or glitches becomes material for your creations. The catch was that initially and officially, the only way to get audio samples into the device was to use an iOS device to record the audio, then transfer it over a 3.5 mm stereo cable to the Volca Sample’s sync input port.

Then Korg released the code for their SDK and almost overnight Rej, developer of theCaustic 3 music creation software released an Android app along with versions for Windows and Mac! While the source code has not been released, the app is known as Caustic Editor for Volca Sample and is available for free from Rej Poirier. Visit his Single Cell Software for downloads and more details on this and his other projects.

Via LearnToMakeHipHop.

Power plug energy meter – Now wireless!

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Kalle Löfgren writes:

Today’s post will cover how I managed to get an Arduino pro mini (3.3V) to sniff the energy meters SPI and transmit the data wirelessly with a nRF24L01+ to an Arduino Nano connected to a computer. The neat thing with this setup is that the Arduino pro mini and the nRF fits perfectly within the casing of the energy meter, and are both driven by the internal power that charges the rechargeable battery that you’ll find in the meter.

Blueprintf – a bluetooth serial monitor

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Bob Alexander of Galactic Studios made this bluetooth serial monitor for embedded microcontroller projects, the Blueprintf:

One way of debugging microcontroller-based projects is to send messages out the UART serial port. Then, a UART-to-USB interface can feed the messages into your PC for display. But I wanted a small, portable device for viewing serial data without a PC, and I wanted it to use my cell phone or tablet for its display.
There are a few advantages to this. First, I don’t always have my PC nearby; maybe the project worked fine on my workbench, but doesn’t work “in the field” where I don’t have a PC handy. Second, the UART-to-USB interface sometimes hangs, especially if there are glitches from the system under test (SUT). Finally, sometimes I just don’t want to string the wires from the embedded system to my PC

Check out the video after the break.

Continue reading “Blueprintf – a bluetooth serial monitor”

3D printing pen

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Jason Poel Smith posted a tutorial on 3D printing pens and how to use them, instructable here:

How Does it Work?
Like all 3D printing devices, a 3D printing pen works by heating a plastic filament to its melting point and forcing it through an extruder tip. This is very similar to how a hot glue gun works. The melted plastic is very soft and can be fused onto a surface or worked into any shape that you want. Once the melted plastic leaves the tip, it begins to quickly cool down. After a few seconds, the plastic hardens and holds whatever shape you have worked it into.

What Can You Do With a 3D pen?
These pens allow you to effectively draw with plastic. You can work the plastic into just about any shape and apply it to most surfaces. You can use it to add raised decorative designs to everyday objects. With practice, you can even make 3D drawings in empty space. These pens can also be used to modify and repair other 3D printed objects.

Check out the video after the break. Continue reading “3D printing pen”

PCB printer

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You can now print your own circuit boards.  Check out this cool Voltera, a circuit board rapid prototyping platform:

Circuit Board Printer
Print dual layer PCBs on FR4 with 10mil space/trace. Our 20mΩ/sq sheet resistance and conventional soldering makes prototyping a breeze

Solder Paste Dispenser
Forget stencils. Pop your board in and dispense solder paste onto printed OR traditionally fabbed boards

Reflow Capabilities
With a 550W heater watch your components reflow and skip the hassle of hand soldering altogether.

Via Make (video).

Check out the video after the break. Continue reading “PCB printer”

Portable VCR Raspberry Pi

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MisterM wrote this instructable detailing his 1981 portable VCR Raspberry PI media centre:

This is an early ’80s Sharp VC-2300H portable VCR that I’ve converted – it now has a Raspberry Pi at its heart, running the excellent Raspbmc media centre software. Other upgrades include a snazzy arduino-based clock and an EL wire “tape” that ejects to reveal the slots of a powered USB hub. The original buttons are used for various functions and it has an integrated 15″ HD screen at the back, with a clear access panel on the side showing off the Pi.

Check out the video after the break. Continue reading “Portable VCR Raspberry Pi”

#FreePCB via Twitter to 2 random RTs

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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.

Tiny NFC reader with a TRF7970A

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Limpkin wrote this blog article about his tiny NFC Reader with a TRF7970A build, and he will be giving a few of them away:

The main components are:
– the USB-enabled ATMega32U4
– a connector for the NRF24L01
– a Lithium-Ion battery charger
– an NFC transceiver
– a proximity sensor
The main idea of this platform is to read NFC tags while keeping its power consumption low. The microcontroller is communicating with the NFC transceiver so you can use the platform as a standalone device or computer peripheral.
You could therefore control a switch (using the expansion header), send the tag data via RF (using a NRF24L01 you’d connect) or simply have the ATMega32U4 forward the read/write commands sent from your computer. The original idea was to support libnfc.

For more details visit Limpki’s website.

App note: Does your op amp oscillate?

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All about Op Amp stability app note from Linear Technology.

Well, it shouldn’t. We analog designers take great pains to make our amplifiers stable when we design them, but there are many situations that cause them to oscillate in the real world. Various types of loads can make them sing. Improperly designed feedback networks can cause instability. Insufficient supply bypassing can offend. Finally, inputs and outputs can oscillate by themselves as one-port systems. This article will address common causes of oscillation and their remedies.