Pocket-sized ultrasonic ruler

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Bergerab made this Instructables detailing the build of his DIY pocket-sized ultrasonic ruler:

Today everything is digitalized. Most of us don’t bother to waste our time using maps, going to the record store, or even going to the DVD store anymore. So… why are so many people using tape-measures and rulers? Yes, they are reliable, but they are certainly not convenient. With innovations, such as ultrasonic range sensors, we have entered a time where you don’t have to bother getting out your old tape-measurer. Using this pocket-sized ultrasonic ruler, you can simply point at any object, click a button, and the distance will be displayed on the 8 LED display. And you don’t have to pay hundreds of dollars, like most commercially available ultrasonic measurers. This ruler is the smallest (5cm by 7cm) and cheapest (about 5 USD) ultrasonic measuring device available today.

Continue reading “Pocket-sized ultrasonic ruler”

Arduino clock generator + divider experiment

John Slee writes:

Anyway, I decided to try to make my own clock divider. Didn’t take long to get something working, and you can see the results in the video above. The genuine Arduino Uno is generating a simple square wave on pin 13, which you can observe with the built-in LED. The Freetronics clone is triggering on the rising edge of the square wave and operating a clock divider with /1 through /8 outputs. The /1 through /4 divider outputs are attached to a little test-LED board I made a while back. You can see that it has a bug caused by my forgetting to reset the tick counter.

To actually use this in a modular synth it would need to tolerate inputs in the range -12V to +12V, maybe via a bunch of MOSFETs. It might be easier to just ditch the AVR and use flip-flops

USB to RS485 adapter

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Brian Dorey made this DIY USB to RS485 adapter, that is available at Github:

We looked for a full-duplex ready-made adapter but all the ones we found are only half duplex devices and as we needed to be able to supply 12 volts via the RJ45 connectors on the slave boards we decided to make our own USB to RS485 full duplex adapter using a USB converter chip from FTDI.
The board uses an FT230X with an RS485 converter chip which outputs to a set of header pins and also an RJ45 socket.
The new adapter board can supply power to the slave devices through the USB port or can be powered from an external supply by removing a power selector jumper. The board also has an on board 120R terminator resistor with selection jumper and LED’s to show serial activity.

Announcing OpenSprinkler Bee (OSBee) Arduino Shield v1.0

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Another open source project from RaysHobby, the OpenSprinkler Bee (OSBee) shield:

OpenSprinkler Bee (OSBee) shield is an open-source Arduino shield for battery-operated (latching solenoid) sprinkler valves. It’s useful for gardening, lawn watering, flower and plant irrigation, and other watering applications. OSBee has a built-in boost converter and H-bridges to control up to four independent valves. The boosting voltage is software defined. The OSBee Arduino library provides easy-to-use software interface. Please check the video and user manual for instructions. Thanks!

Via the contact form.

Check out the video after the break. Continue reading “Announcing OpenSprinkler Bee (OSBee) Arduino Shield v1.0”

Hacker Camp Shenzhen: Yet another video from Gary Fletcher

By DP

Gary Fletcher shared this Shenzhen trip video he made:

So anyway, here is a snippet of our 10 days in China/Hong Kong — a stretch that included everything from street food stalls to a surprisingly long conversation with a hostel barmate in Wan Chai who reviewed top bitcoin casinos for a living and had opinions about Macau’s future that were genuinely worth hearing — in what I am calling a Blogamentory (my perspective), but there is some more professional stuff from the guys on their own site you’ll want to dig into here.

Thanks again guys and for those of you that get a chance if there is a next time be quick! its awesome!

Via Hacker Camp Shenzhen mini-site: Hacker Camp Shenzhen: Yet another video from Gary Fletcher

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: USB port protection

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USB port protection from EMI and ESD, a good app note from Würth Elektronik introduce you to their common mode chokes and TVS diodes solution. Whole article here in PDF.

The USB-Interface might be the most distributed PC interface in the world. The usage in industry applications is more and more common. Let’s have a closer look to the special environmental conditions of industry applications. That there are real concerns regarding the robustness against EMI and ESD is written in Intel’s “High Speed USB Platform Design Guidelines”. Intel recommends the usage of a common mode choke for EMI suppressions and another component for protection against ESD pulses.

App note: STM32 microcontroller system memory boot mode

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Here’s an app note from ST discussing how the bootloader works and how it’s activated –the general concept of the bootloader (PDF!):

The bootloader is stored in the internal boot ROM memory (system memory) of STM32
devices. It is programmed by ST during production. Its main task is to download the
application program to the internal Flash memory through one of the available serial
peripherals (USART, CAN, USB, I2C, SPI, etc.). A communication protocol is defined for
each serial interface, with a compatible command set and sequences.

This document applies to the products listed in Table 1. They are referred as STM32
throughout the document.

minDUINO v1.5, a small footprint, educational Arduino clone

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Steve Smith G0TDJ  of ProjectAVR writes:

The minDUINO is designed to be easy to assemble, so it is a two layer through-hole design, not SMD. It has headers for FTDI, ISCP and port breakouts. Another project I designed was VAYU-NTX, a High Altitude Balloon Tracker. As expansion for this, I designed two small daughter boards for experimenting with. I followed a similar idea with the minDUINO and placed the breakout headers together. Later on, I may design a bespoke board but its just as easy to use stripboard/perfboard paired with the appropriate header socket.

Design files are available here.

DIY CNC pendant

DIY-CNC-Pendant

A DIY CNC pendant made by Bob Davis.  He wrote a post on his blog detailing it’s assembly:

Last night I finished building my DIY CNC pendant and tested it out.  I still need to add a manual jogger to it someday.  It is made out of an old Zenith TV remote control.  The key is to have three position toggle switches.  I have a lot of them laying around that were left over from another project.  You can build this for about $25 or for free in my case because I used parts that I had laying around.  It will be in my next book “Arduino CNC Projects”.

Via Hacked Gadgets.

Check out the video after the break.

Continue reading “DIY CNC pendant”

Free PCB coupon via Facebook to 2 random commenters

STICKERSEvery Friday we giveaway 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 June 13, 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

Insomni’hack CTF 2014: Bus Pirate used as a serial interface to communicate with the MSP430 microcontroller

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Bus Pirate was used to communicate to a MSP430 microcontroller  at Insomni’hack CTF2014 challenge.  q3k of DragonSector writes:

The devboard is obviously a Texas Instruments MSP430 launchpad. Attached to it is a Bus Pirate used as a serial interface, and a round device of no obvious use… What could it be..?
Nicolas, the author of this challenge, explained that it is a simple display controlled by a servo. If you rotate the motor, the flag will be revealed underneath the red cover! To rotate the motor, you need to input a password via UART/Serial. Alright then, let’s get cracking – this is going to be fun.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Debricking Seagate Dockstar

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ZsZs  documented his Dockstar debricking with the Bus Pirate:

Somehow I managed to brick my Dockstar. It was so simple like the first sentence :) The debricking process was quite long due to lack of experience and tools. Tools required:
– A buspirate card (I have a v3.6)
– openocd with buspirate support
– An USB2serial converter (3.3V version!) . Tip: search “CP2102 usb serial” on Ebay. You’ll get tons for a few bucks.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Logic Pirate back in stock

Logic Pirate

Logic Pirate is back in stock at Seeed Studio.  It is an inexpensive, yet capable open source logic analyzer. It can sample 8 channels at 20 million samples per second, and may be overclocked for even faster acquisitions. It’s designed to support the open source SUMP logic analyzer protocol with software available for most operating systems.

You can get a Logic Pirate for $30.

2.4 megasamples per second continuous AVR logic capture

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From the comments on our earlier Turning the Freedom board into a Logic Analyzer post, Ralph Doncaster writes:

For situations where the samples will fit in RAM, this is good.
For long sampling periods I used a USBasp and a PL-2303HX to make a logic analyzer that can sample 2 lines at 2.4 msps or 8 lines at 600ksps.

Via the comments.

LED VU Meter with LM3916

LED VU Meter (2)

xristost has written an article about his latest project LED VU meter with LM3916:

This was finished months ago and just now I had time to finish the article. LM3916 is a dedicated IC for VU LED meter. Unlike LM3915 which have 3dB step between voltage levels, the LM3916 have nonlinear steps: -20, -10, -7, -5, -3, -1, 0, +1, +2, +3db, just like old school analog VU meters. I saw in YouTube an interesting commercial LED VU meter, which imitates the needle movement in analog VU meters and I thought I can make a similar one. All I needed I found in the datasheet of LM3916.
The LM3916 can be feed with AC signal without any rectification, but I wanted to implement a precision full wave rectification.

Check out the video after the break. Continue reading “LED VU Meter with LM3916”

Mechanical ball clock

In this video Turnvater Janosch demonstrates his homemade mechanical ball clock:

The clock runs for 12 hours, driven by a weight of 2.5 kg sinking approx. 1 meter during that time..Every minute a marble is lifted up and goes down a marble run with three flipping traps that count marbles for minutes, five-minute-steps and hours.
The timekeeping element is a second-pendulum with a pinwheel escapement.

Via Hacked Gadgets.