App note: USB HID lithium-ion battery charging via USB with ATmega16/32U4

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This app note discusses how to use the Atmel® EVK527 evaluation kit to
charge Lithium-Ion (Li-Ion) batteries using USB connection as power supply:

This document (PDF!) describes an application running on the Atmel EVK527 evaluation kit. The EVK527 is dedicated to the
Atmel ATmega16/32U4.
The USB offers a 5V power supply on the VBUS pin. The available current range is from 100mA to 500mA. This is
enough to charge a Li-Ion battery cell.
A Li-Ion cell needs an accurate control of voltage and current during charge.
ATmega16/32U4 offers a USB full speed interface, PWM channels and 10-bit ADC channels. All these features are
used to perform a Li-Ion battery charger via USB.

Nixie clock: 4 – the touch sensor

This video of Luca Dentella demonstrates the IQS127D touch sensor and an Arduino:

My Nixie clock won’t have any visible buttons, so I chose to use a touch sensor, that signals to Arduino when the user touches the clock.

I brought from SureElectronics the Capacitive Proximity and Touch Button Control module, based on the IQS127D IC by Azoteq.

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:

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

Kicad Tutorial: Copper pours / fills

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Here’s another Kicad tutorial  by Wayne and Layne: Copper pours / fills:

A copper pour or fill refers to an area on a printed circuit board where the original copper is not etched away, and remains in place, usually electrically connected to the Ground signal, producing a “Ground Plane”. This has a number of advantages, including decreasing the amount of etching fluid required during manufacturing, as well as reducing the amount of electrical noise and signal crosstalk experienced by the circuit elements.

The Annoy: a 10F202 based tiny intelligent buzzer


Chris from PyroElectro sent in this link to his project post for a device which generates some chirping and buzz-like noises every few minutes in order to slowly drive people nearby insane. The circuit consists of a PIC 10F202 MCU, two caps, CR2032 battery and speaker. He built the project as a way to illustrate to beginners how you can make such projects extremely small with the tiny (and inexpensive) surface mount parts available today.

Via the contact form.

Week in (p)review March 01, 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

DEFCON 20: RenderMan on ADS-B aero radio


Brad Haines (RenderMan) CISSP, is a Whitehat by trade, Blackhat by fashion, who presented this talk at DEFCON 20. For those of you unfamiliar with him, RenderMan has a history of hacking RF who’s rumored to be a member of the Church of WiFi. In this presentation he turns his attention to ADS-B (Automatic Dependent Surveillance-Broadcast), a common technology installed or being installed on a vast majority of commercial airliners that involves an unencrypted and unauthenticated radio broadcast. He explores the system’s features and weaknesses, noting what can happen when security is not built in from the beginning. He hopes that this serves tospur more research and investigation into this field.

Smoke Tester v1 free PCB build

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Ptarmigan labs blogged about his free Smoke Tester v1 PCB build. It’s a board designed to safely power your prototypes, and check if they have a short somewhere using just about any available supply.

A while back I got a free PCB from Dangerous Prototype’s Free PCB program. It’s a nice little board designed to provide easy current monitoring during prototype stages of a project. Features include over-current tripping with visual indication, as well as dual 5V and 3.3V supplies.

If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.

Via twitter.

Workshop Update for February 27th, 2013

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Slowly building up the library of models for the Bus Pirate Edu Kit exercises. To make sure everyone can easily hook up any exercise, we’ll add top-down views, schematics, and wiring tables. Here’s an example of a wiring table for the exercise above.

MCP9701A

  • Pin1 – E1
  • Pin2 – E2
  • Pin3 – E3

Wires

  • Black: Bus Pirate GND – A3
  • Yellow: Bus Pirate ADC – A2
  • Red: Bus Pirate 5V – A1

As always comments and suggestions are very welcome.

Controller for soldering irons using the Hakko T12 type tips

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Sparkybg shared his controller for soldering irons using Hakko T12 type tipe in the project log forum:

T12 have thermocouple in series with the heater with a voltage of around 9mV at 450 degrees celsius, so the voltage to the heater must be turned off to measure the voltage of the thermocouple. Don’t measure the resistance of T12. It is pointless to use it when a thermocouple is already available, and is far more precise than resistance.

Via the forum.

QR clock

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Markus shared his QR clock in the project log forum:

being inspired by ch00ftech’s QR clock  I made my own variation of this nice idea: A PIC32 decodes the time signal from a DCF77 receiver, calculates a QR code containing this time information, and displays it animated at 30 FPS on a ST7735R LCD. Without a radio signal the QR code is being displayed in b/w. A nice plasma effect is added when it locks to the DCF77 signal.

Check out the video after the break.

Continue reading “QR clock”

PIC16F74 – room thermostat with colour LCD

Room thermostat with PIC16F74, DS1820, and the Siemens M55 color LCD:

The heart of the unit is an 8 bit PIC16F74 microcontroller from Microchip. It’s main task is to constantly monitor the room temperature trough a 1–wire digital thermometer IC, a DS1820 from Maxim, and to switch a relay on or off, that controls the gas boiler accordingly. The system also features a color LCD, which was removed from an old mobile phone, a few LED’s, an LDR sensor for night mode and a couple of pushbuttons

Via Electronics Lab.

Bus Pirate Demo board v5 free PCB build

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j_dja tweeted his Bus Pirate Demo Board v5c free PCB build. This board was designed to emulate various different ICs with which the Bus Pirate can talk to. I2c, SPI, and UART protocols are supported, with device emulation for RAM, ADC, DAC, and a PWM generator. These features help researchers practice probing embedded systems before moving on to live targets, exploring everything from consumer smart home hubs to the dedicated hardware authenticators built for online casinos.

@dangerousproto the solder reflow started 1min 40sec at highest temp setting

If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.