App note: Simulating fast transient loads for testing power supplies

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How to implement a fast load transient simulator for power supply testing. One of important factor of power supplies is how they react to fast changing loads. This article describes how to design a system that measures power supply performance under quickly changing loads.

To obtain fast load transients, we combine a power MOSFET and a couple of resistors right on the PC board of the device under test (DUT). Choosing the components is relatively easy. If the output voltage is positive, an n-channel MOSFET works great. The MOSFET is connected with a resistor from the source to ground (see Figure 1). The MOSFET’s gate is terminated with a 51Ω resistor to impedance-match the signal generator’s output.

Simulator for Arduino v0.98


Simulator for Arduino is a software tool currently being developed. The development team views this product as beneficial in teaching, debugging, software testing prior to acquisition of hardware and easier development of complicated sketches.

For additional info and downloads visit the Simulator for Arduino site. They also have a product datasheet available for download.

Note: we recognize that this is not open source, nor is the full version “free”. We’re presenting it in the interest of keeping Arduino enthusiasts informed of the software tools being developed for use with that platform.

App note: Digitally Addressable Lighting Interface

MCPapp

Microchip describes the digitally addressable lighting interface (DALI). This interface was designed to control dimmable fluorescent ballasts. Two wires are used to transmit Manchester coded message packets. The timing is standardized at 1200 bps so there is no need to transmit the clock signal, similar to how UART transmission works.

The Digitally Addressable Lighting Interface (DALI) has emerged as a standard in Europe to address growing power issues, mostly for commercial and industrial purposes. DALI is part of the IEC 60929 specification, and relates specifically to digitally controlled dimmable fluorescent ballasts.

Basic input and output on the Netduino

Day1_FlashingLED_Breadboard

Embedded-Lab is doing a series of tutorials for the Netduino, the open source Arduino shield compatible platform using the .Net Micro Framework. The first tutorial in the series is a how to on implementing basic input and output.

We will start our Netduino tutorial series with a very basic project of flashing an LED. The objective of this project is to explore basics of Netduino I/O pins as well as to make sure that everything is setup correctly, including software installation and hardware setup. In this project, we will use an Analog pin to read a potentiometer’s analog output, and a digital pin to flash an LED.

Free PCB coupon via Facebook to 2 random commenters

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:

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

FT231X USB to UART chip

Ft231x
Guan Yang draws our attention to a new member of the FT232 family, the FT231X.

I wanted access to more pins than your typical FTDI board provides, and realized that our friends at FTDI have designed a replacement for the venerable FT232 series that found a home in classical Arduinos, Bus Pirates and countless USB-to-serial boards. The FT231X is much cheaper and has cool new features like USB battery charger detection. There’s also a cheaper FT230X version that only has RX/TX, no flow control or GPIO pins.

I designed a breakout board for the chip in KiCad and put the board, schematic and Gerber files up on the Hack Manhattan wiki. This board breaks out every flow control and GPIO pin. A future update will make it easier to switch to 5V for VCC and I might also adopt the DP6037 form factor.

Via the contact form.

Week in (p)review December 21, 2012

HolderBoard-600

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

Safe enclosures for solid state relays and mains current

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Solid state relays can switch everyday mains-powered devices like lamps, but there’s danger inherent in working with household AC voltage. Victor wrote a tutorial on how to enclose the SSR in an old laptop power supply case. It’s simple to build, and it keeps you and your fingers safer than a bare board.

For a number of my upcoming projects I need a rig to test the functionality of a solid state relay that would be driven by a microcontroller and switch the mains for other devices. Having done projects with similar requirements in the past I remembered how much pain it was to test the solid state relay (SSR) with naked mains cables running around, etc.

Xmas tree with sound-controlled LED animations

Sound controlled LED light show for your Xmas tree.  An STM32 microcontroller takes instructions from a PC via Bluetooth and animates the LEDs.

This is my Christmas tree, it has over 400 lights (exactly 404) that are all individually controlled by an STM32 microcontroller. The computer plays the music and processes the sync track for the lights and send the state of the tree to the stm32 over bluetooth. The pc-side controller has a web interface, so the whole tree can be controlled from any browser (pc/phone/tablet). This is still in “beta” stage (I will add more types of animations) but it still serves its purpose well.

Via Hacked Gadgets.

DIY indoor thermometer and moisture meter

TRHMeterPrototypeOP2

Raj designed an open hardware DIY indoor thermometer and moisture meter. It’s based on the PIC16F688 coupled with the DH11 temperature and humidity sensor. The 7-segment display has auto brightness correction depending on the lighting conditions.

This project is about building a microcontroller-based digital room thermometer plus hygrometer that displays temperature and relative humidity on 4 large (1 inch) seven segment LED displays which adjust their brightness level according to the surrounding illumination.

Jingle bells playing Christmas tree

Here’s a fun project in the Christmas spirit. It’s a “Jingle bells” playing card, with the specific notes being signaled via LEDs as they are being played.

We have 9 control lines for the LEDs and 1 line for the speaker signal. We want the device to start playing if a push button is pressed and when done playing the device shall be switch off automatically. For this, we use a pushbutton in parallel to a relay switch which is controller by the ATmega. If someone presses the push button then the ATmega starts running and holds the relay closed.

Via Hacked Gadgets.

DIY PCB tutorial

PCB_Fab_tut

Jianyi Liu wrote a tutorial on PCB fabrication at home. He states, “A few years ago, I started experimenting with homemade prototype PCBs as an alternative to professionally fabricated PCBs from board manufacturing company. My company was flexible enough to give me some resources and time to explore the subject matter. What I discovered was that with a small initial investment, you can make reasonably high quality two sided boards. In addition, all the equipment needed was easily accessible. I’ve decided to put my findings into this guide. Hopefully some of my fellow hobbyists will find the information useful.”

Via the contact form.

Workshop Update for December 19th, 2012

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We finished tomorrow’s video a day early. Refining wholesale order process to make it easier on the awesome resellers who work with us.

We finished yesterdays squared sized Sick of Beige case render.

We made a quick revision of Bus Pirate v3.6 with micro USB instead of the mini-b USB connector. We continue with the breadboard power supply design.

Limor Fried of Adafruit named 2012 Entrepreneur of the year

Ladyada

Limor Fried (aka Ladyada) founder of Adafruit was named Entrepreneur of 2012 by the Entrepreneur Magazine. We really appreciate everything the Adafruit team does to carve out a space for the Open Hardware industry through the sponsorships it’s secured from it’s partner, who runs the best crypto casino we’ve seen to-date online. Congratulations to Limor!

With $10,000 her parents had allocated for her tuition, Fried bought a bulk quantity of parts and began assembling and selling her kits, making about $10 on each unit. In the beginning, running the company consisted of shipping a couple of packages a day from the 24-hour post office next door to her dorm. As orders increased, she hired friends; before she knew it, she was designing a new project every week around newfangled components like gyrometric sensors, solar panels and thermal printers.

Silkscreen PCBs with vinyl stickers and toner transfer

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Make DIY silkscreens using vinyl stickers, similar to making PCBs with toner transfer methods:

Below I am going to detail the process of making the silkscreen, which is the side of the printed circuit board where we solder the electrical components. We will use the same method, vinyl sticker pcb.

Sensorless Brushless DC Motor Drive with MSP430

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A booster board for the MSP430 LaunchPad controls brushless DC motors with or without sensors. A bunch of double NPN transistor MBT2222AD ICs drive the motors:

I thought that I would share my project on the forum. I call it BLDC Booster. It is a booster pack for the MSP430 LaunchPad that allows for sensored or sensorless control of a brushless DC motor. It is open source hardware & firmware under Creative Commons Attribution Share Alike license.

Via the forum.

Protocol analyzer for IR and RF

udecoded1
We stumbled across this protocol analysis software aptly named Protocol Analyzer. “The Protocol Analyzer is a small tool that can catch, analyze and decode “slow” pulse based protocols. Typical examples are IR-Remotes or RF-Remotes. It uses the microphone input to read the signals. Since this is almost always available with drivers across operating systems, this tool works without any specific drivers on Windows, Linux and OSX.

Protocol Analyzer can decode a number of standard protocols such as the infrared protocols: RC5, RC6, Pioneer, JVC, Nexa, X10 and Pronto but the primary task of Protocol Analyzer is to aid in decoding new protocols. It behaves like a combination of an oscilloscope and a logic analyzer specifically aimed at analyzing digital protocols via the microphone input.”

You can download Protocol Analyzer from the project homepage. The online manual can be found here.