Free PCB Sunday: Pick your PCB

IRToy

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:

Continue reading “Free PCB Sunday: Pick your PCB”

App note: Low drop out, phase margin, and stability

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Old app note from Fairchild Semiconductor about external component effects on LDOs. Link here (PDF!)

Low drop-out (LDO) regulators are one of the basic building blocks of most power supplies used in today’s electronics. Their ease of use, low cost, and small size makes them ideal in portable and handheld applications. They are available in wide variety of voltage & current levels with their primary function, to provide power to low-voltage digital circuits. The only other necessary components are external capacitances, which, in conjunction with the LDO, create a complete power solution. This application note reviews the effect of these components and their phase shifts on the LDO’s loop stability and show how to tailor the compensation to obtain a stable circuit.

 

App note: 1-μA capacitive grip detection based on MSP430 Microcontrollers

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An app note from TI, 1-μA capacitive grip detection based on MSP430 Microcontrollers (PDF!)

This application report  discusseshow to design a simple and ultra low-power grip detector Booster Pack for the MSP430 LaunchPad. The PINOSC feature in every msp430G2xx2 and msp430G2xx3 device makes it possible to eliminate all the external components when implementing a capacitive touch design. All the components used in the grip detector, such as capacitive sensors, LEDs are all integrated in a BoosterPack, which is completely compatible with the MSP430 LaunchPad interface. And this grip detector canalso communicate with the TouchPro graphical user interface (GUI) to make the test and debug process much faster and easier. Measurement results show that the average current consumed by this grip detector working in idle mode is nearly 1μA, which proves that the MSP430 value line series of devices have excellent low-power characteristics and are suitable for battery powered applications.

 

 

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”

USB power supply active load tester

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Sasa Karanovic has designed and built a DIY USB power Supply active load tester, that is available at GitHub:

USB Power supply Active Load Tester or short PAL Tester is unit designed for testing the quality of the power supplies.
Idea was to create low-cost, precise device for simultaneous measurement of Voltage and Current drawn from the device under test.

Project info at Sasa Karanovic blog.

ArTICL: Arduino and MSP432 Launchpad to TI graphing calculator linking

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KermMartian over at Cemetech forum writes:

A few weeks ago, I received a pair of MSP432 Launchpad development boards courtesy of Texas Instruments, and two weeks ago, I began porting ArTICL to the MSP432. I’m happy to announce that ArTICL is now available to MSP432 Launchpad programs. First developed last year as an upgrade to my much-used but unpolished Arduino-TI calculator linking routines, ArTICL offers an easy interface to communicate between TI calculators and microcontroller development boards. ArTICL (which stands for Arduino TI Calculator Link) lets TI-83 Plus, TI-84 Plus, and other TI graphing calculators send and receive numbers, lists, strings, pictures, and other data types by making the Arduino or MSP432 emulate another calculator or a CBL2 device.

More details at Cemetech site.

How to make two ESP8266 talk

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Here’s a detailed tutorial on how to make two ESP8266 talk with each other from Rui Santos:

How it works? You’re going to set one ESP as an Access Point (Server) and another ESP as a Station (Client). Then they’ll establish a wireless communication and the Client sends a message to the Server saying “Hello World!”.

Project info at Rui’s Random Nerd Tutorials site.

SXAM: A Spark.io indoor ambient quality monitor

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Davide Gironi published a new build, a Spark.io indoor ambient quality monitor:

SXAM (Spark to Xively AMbient quality monitor), is an ambient quality monitor that logs 4 environmental parameters to the xively.com and display the ambient status by using for RGB leds.
SXAM logs:

  • Humidity
  • Temperature
  • Ambient noise
  • Brightness

Project info at Davide’s blog.

Check out the video after the break. Continue reading “SXAM: A Spark.io indoor ambient quality monitor”

#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.

A XSVF assembler/disassembler in python

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Marcelo Roberto Jimenez wrote an assembler/disassembler for XSVF, he writes:

As a sequence of my last project, the JTAG/XSVF library for Arduino, I felt I needed a XSVF assembler and disassembler, so that I could hack JTAG a little bit. I found that XSVF is very convenient, much more than SVF when you are dealing with a single component in the JTAG chain. I also found out that the XSVF files produced by programmers are very inefficient and full of unnecessary stuf. It would be great if I could write my own XSVF files.

Code is on github.

Details at Marcelo’s EE & CS blog.

Make your own Katy

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Steve Chamberlin wrote a how-to on building your own 68 Katy. We wrote about it previously:

Assembling the PCB requires soldering one surface mount component, the 44 pin CPLD in TQFP package. It can be soldered with a standard iron using the drag soldering method (my preference), with hot air, or with a toaster oven reflow. The rest of the components are easy through-hole parts.

You’ll need an EPROM burner to program the initial flash ROM data, as well as a JTAG programmer for the CPLD. I used a Bus Pirate with the XSVF player firmware to program the CPLD.

Project info at Big Mess o’ Wires site.

Get an assembled Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

App note: Consideration of power MOSFETs in fast charger design

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App note from Fairchild Semiconductors on power MOSFETs selection including thermal design and usage on fast chargers. Link here (PDF)

The demand for battery capacitance up to 10,000mAh in mobile devices is steadily increasing as devices consume more power and offering more functionality. Large battery capacity provides longer battery run-time, but needs more time to charge. This application note describes how to decrease charge time and the  impact of power MOSFET selection, including a practical design example. The one serial and three parallel (1S3P) 9,700mAh Li-Ion battery is used and 1C and 0.5C rates are set to measure charging and discharging time, respectively. Products that require large battery capacitance and fast charging time include tablet/notebook docking stations, portable music players, and commercial electronic Point-of-Sale(POS) systems.

Free PCB Sunday: Pick your PCB

IRToy

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:

Continue reading “Free PCB Sunday: Pick your PCB”

App note: Performance restrictions associated with 3.5 watts SO-8 power MOSFETs

an_fairchild_an1032

Old app note from Fairchild Semiconductors on SO-8 power MOSFETs’ power handling. Link here

In applications requiring high current and small footprint electronic switches, a Power MOSFET packaged in an SO-8 is usually the best choice. This is because the combination offers low on-resistance and reasonable power handling. A second benefit is the numerous suppliers for this product. As a result, SO-8 Power MOSFETs are commonly found in applications such as notebook computer DC-DC converters, battery chargers, and disk drive motor controls.

SO-8 packaged Power MOSFETs handle about one Watt under “typical” conditions, regardless of the silicon size. The thermal capability of any semiconductor is strongly related to the operating conditions, however users often overlook the importance of such criteria. In addition, the lack of an industry standard means that MOSFET manufacturers may mislead the power handling of SO-8 Power MOSFETs by two to four times their typical thermal capability. Users should also remember that current handling is proportional to power handling. By simply manipulating the power rating conditions, MOSFET manufacturers can tailor any current rating to any “non-typical” condition.

App note: Zero Latency Multiplexing I/O for ASIC Emulation

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Zero Latency Multiplexing I/O for ASIC Emulation (PDF!) application note from Xilinx:

This application note provides a method for FPGA emulation platforms to communicate multiple signals over one I/O or I/O differential pair to another FPGA. This multiplexing method serializes data up to 800 Mb/s without introducing any additional cycles of latency to the user who is running at a slower rate.

Free PCB coupon via Facebook to 2 random commenters

BP

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”

CDC serial driver for Bus Pirate v4 on Windows 7 64-bits

BPv4

kaupunkish@ writes:

I managed to fix this problem by googling.  All I did was changing VID and PID to what I have in Bus Pirate and then naming it nicely at the end of INF. Voila! I was able to update driver software.
I am not specialist in this area, so I am just telling how I hacked it for myself. Maybe you can make better use of this info and implement out-of-box installation on win7 x64 I am attaching hacked INF file that I used successfully

Issue reported on code.google.com.

You can get a Bus Pirate v4 for $40, including worldwide shipping.

Soldering iron + Nodemcu = IoT device

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Vegard Paulsen blogged about his soldering-iron #IoT project:

My trusty old soldering-iron recently got an upgrade!
With the help of a NodeMCU. a RGB-LED it now reports the set temperature to the #IoT Thingspeak.com server through WIFI.
It also sends me Prowl messages on my Iphone when I forget to turn it off.
It all started when I needed to fix the display on the Soldering-iron itself after some guys at the soldering-iron factory forgot to mount the segment display properly.
The road to IoT is anything but streamlined yet. The NodeMCU & Arduino IDE integration is in it early stages and the tutorials out there are few and full of frustation.