SIM900 USB Communication using MCP2200

in project logs, USB by DP | 0 comments

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Here’s a simple USB interface to communicate with a SIM900 modem by Jesus Echavarria.   He wrote a post on his blog detailing its assembly:

Hi all! Here’s the new project where I’m working a couple of days. Since I develop the SIM900 module and test it, I don’t work with it. Also, I’ve got at home some samples of the MCP2200 USB bridge that I want to test it. So make an USB interface for this board was the perfect idea! This allows to use the SIM900 board with a PC, Raspberry or similar, with the plus of no need external power supply or control signals. Just plug the USB cable on the board and start communicating with the world!

Project details at Jesus Echavarria’s blog.

Via the contact form.

Bus Pirate v3.8 free PCB build

in builds by DP | 0 comments

CG1s6I2UYAEWiYu

@tecnotopia tweeted picture of his free Bus Pirate v3.8 PCB build.  The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff.

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.

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

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Thoughts and rumors about Hacker Camp Shenzhen & Maker Faire

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This past week we rocked Hacker Camp 5 and Shenzhen Maker Faire. It was a huge party, as always, thank you to everyone who came!

Instead of covering the camp and fair directly, we saved the images and chat transcript from the shenzhen_hacker_bei group on WeChat. Nearly 100 hackers, makers, and organizers shared a week long discussion. Hopefully this is a very different  perspective than you’ll get from anywhere else. We’ll clean it up and post it in the forum and blog over the coming week.

China is embracing hacking, making, to an insane extent. Local, provincial, and national governments are all funding hackerspaces and promoting innovation. The Shenzhen Maker Faire is probably the most impressive Maker Faire I’ve ever been to in terms of infrastructure and presentation.

Open source seems to be on fire in China. At the first Shenzhen Maker Fair I explained open source to skeptical locals. This year almost every major product on display was open hardware (or claimed to be…).

Here are some whispers, gossip, rumors, and outright lies overheard at Hacker Camp and Maker Faire. None of this should be taken as true and is totally unverified:

  • Seeed Studio has an new office in a technology park funded by China’s Innofund and is going IPO, possibly a local hacker space too
  • Radio Shack is opening a new chain that finally brings mobile phones to the totally under served Asian market. They will have a section with Hackcelerator projects. #shax
  • Make Block has a paper valuation around 50M
  • Business accelerators are out, decelerators are the new hotness. Keep an eye on this space
  • Whatever remains of Arduino after nasty infighting supposedly doesn’t own the Arduino trademark in China (and some other places). They’ve released Genuino for the Chinese market with a new name, and 39RMB ($6) price tag to complete with 10RMB clones on Taobao. Seeed is manufacturing it. Hey guys, looking for US distributors? #peak-duino
  • While 3D printers are still an enormous part of the fair, it seems to be giving away to wireless dev boards. #50dollar3dprinter
  • Hacker Camp has been an amazing run: 5 camps in 18 months, more than 100 participants. We’ve never met a group of more interesting and talented people. We’re not sure what happens next, but no more camps are scheduled. There will probably be a smaller and more informal successor, we’re still scheming
  • Hack a Day throws a kick sass party with local brews from Joe @ Bionic Brew and China pizza champions NYPD. Thanks guys! #poolsidebusinessmeeting
  • Bunnie is now doing angel funding, slamming down 2 big reds for a new industrial waste stream recovery project. Mike @ Hack a Day’s LED hat was spotted scrolling the name of the same company at the Maker Faire after party. #theexpresswaytogreatness

 

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 40 comments

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 →

Posted in Free PCBs | Tagged | 40 Comments

App note: Low cost I2C level translator

in app notes by DP | 1 comment

an_siliconlabs_an869

2 Diodes, 3 resistors and a transistor here’s Silicon Labs’ low cost solution on voltage level translation. Link here

This applications note discusses a low-cost circuit for I2C level translation. This circuit was developed for the Si701x, Si702x, and Si703x humidity sensors but will work in many applications. This circuit provides I2C level translation from a higher voltage supply, such as 5 V, to a lower voltage, supply such as 1.8 or 3.3 V. In addition, the optional emitter follower circuit provides a low-voltage power supply rail from the higher 5 V supply. Note that some devices allow for higher voltage tolerance on I2C inputs. For example, the Si7034 has a 3.3 V tolerant I2C interface, so the level translation is only required for 5 V I2C designs.

App note: Isolator vs. optocoupler technology

in app notes by DP | 1 comment

an_siliconlabs_isolators_comparison

Great read from Silicon Labs on comparison of isolation technologies namely optocouplers and digital isolators. Link is here

Optocouplers have been the unchallenged signal isolation solution for more than four decades, but digital isolators fabricated in complementary metallic oxide semiconductor (CMOS) process technology are gaining favor in the design community because of their superior performance, reliability and integration.

App note: Implementing a TMDS video interface in the Spartan-6 FPGA

in app notes by DP | 0 comments

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Implementing a TMDS video interface in the Spartan-6 FPGA, an app note here (PDF!) from Xilinx:

The DVI and HDMI protocols use TMDS at the physical layer. The TMDS throughput is a function of the serial data rate of the video screen mode being transmitted. This in turn determines the FPGA speed grade that must be used to support this throughput. After the Spartan-3A family, Xilinx has offered embedded electrically-compliant TMDS I/O allowing implementation of DVI and HDMI interfaces inside the FPGA. The operation theory for this is detailed in Video Connectivity Using TMDS I/O in Spartan-3A FPGAs. The data throughput in that application note was maximized at 666 Mb/s in the fastest speed grade. The Spartan-6 FPGA on the other hand has made significant speed improvements. Table 1 shows the maximum throughput for each speed grade of the Spartan-6 FPGA.

tinyK20: New board with micro-SD card

in ARM by DP | 0 comments

tinyk20-thumb-drive-bottom-side

Erich of MCU on Eclipse has posted an update on his open source tinyK20 project. We wrote about it previously:

Changes from the earlier version (see “tinyK20 Open Source ARM Debug/Universal Board – First Prototypes“):
1.Replaced the K20 crystal with one having a smaller footprint.
2.Added Micro SD card socket on the back (same socket as on the FRDM-K64F or FRDM-K22F).
3.Because SD cards can draw more than the 120 mA the K20 internal 3.3V provided, there is a footprint on the backside of the board to add an extra DC-DC converter.
4.Moved reset button and headers.
5.First version with transparent enclosure.

USB Infrared Toy free PCB build

in builds by DP | 0 comments

USBIRToy3-02

Iñigo of Elektroquark built a free USB IR Toy PCB. With the USB IR Toy you can use a remote control with your computer, view infrared signals on a logic analyzer, capture and replay remote control buttons.

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.

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

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#FreePCB via Twitter to 2 random RTs

in Free PCBs by DP | 0 comments

buspiratev383

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.

Video: Wireless Intrusion Detection System with Raspberry Pi


Chris Jenks presented at this weekend’s Circle City Con in Indianapolis, IN. Chris is a graduate from Eastern Michigan University with a Bachelor of Science in Information Assurance. He works full time doing security audits, firewall design, network consulting, and troubleshooting. His Raspberry Pi WIDs was published in the Linux Journal in December 2014, and the talk is related to the article.

The hardware used in this project includes a Raspberry Pi model B+ or Pi 2 with Kali Linux installed on a 16gig SD; a TP-Link WN722N Wireless adapter; a portable switch; network cable, a laptop; and a Raspberry Pi power supply.

App note: Electromagnetic Compatibility (EMC / EMI) for Vibe Motors

in app notes by DP | 0 comments

an_precision_microdrives_AB-005

Here’s an App note from Precision Microdrives on EMI from vibration motors and their Electromagnetic compatibility. Link is here

Electromagnetic interference (EMI) is the radiation or induction of electromagnetic noise on a system. DC motors are a common source of EMI, as are most electromagnetic circuit components. They are potential sources of noise and can generate common-mode currents. EMI can result in degraded performance, data corruption, or if strong enough can cause the system to fail completely. EMI can be radiated or conducted comes from magnetic and electrical sources, respectively. In the case of DC motors, both radiated and conducted emissions are present.

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 50 comments

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 →

Posted in Free PCBs | Tagged | 50 Comments

App note: Measuring RPM from back EMF

in app notes by DP | 1 comment

an_precision_microdrives_RPM_through_Bemf

Interesting App note from Precision Microdrives on finding RPM using back EMF. Link is here

Measuring the speed of a motor can be an important requirement for some applications. For example DC and gearmotors that are moving loads may require close monitoring or adjustment of the output speed.

External sensors are typically used for speed measurements, such as Hall sensors with a magnet mounted on the shaft, or transoptors with a slotted plate (also mounted on the motor shaft).

These sensors that can give accurate information about motor speed require space and increase cost of parts. Sometimes it’s impossible to add an external sensor to a motor due to space or pricing restrictions.

We can properties of the motor itself for a low-cost RPM measurement, which is based on the back EMF. In fact the back EMF is a very important measurement for haptic feedback chips when driving vibration motors and LRAs.

We’ll explain a sensorless method, where we use an Analogue to Digital Converter which is onboard our microcontroller that generates the PWM drive signal. We haven’t included any additional measurement chips or components.

TI Design Contest: Envision the ultimate NFC wearable

LaunchYourDesignTI
TI has announced a contest for NFC based wearable designs.

Do you dream of creating a solution to make monitoring health and fitness activities easier? Using near field communication (NFC) in your designs can help! We want to hear your ideas for the next wearable design based on our RF430FRL15xH NFC sensor transponder in our ultimate NFC wearable design contest. There’s no need to actually create your design just yet — all you need to do is share your concept with us. If your design concept wins, you’ll receive the tools you need to get started and potentially be eligible to win a Sony SW3 SmartWatch 3 SWR50. Additionally, finalists will have the opportunity to be featured in a blog post on the Launch Your Design blog.

The deadline for submissions to TI is July 17, 2015. For more information and contest rules, visit TI’s contest page.

Sniffing GSM traffic with HackRF and GNU Radio

Ziggy and company have been experimenting with the HackRF and exploring GSM signals.

While my friend and colleague Simone was visiting our ZIMPERIUM – Enterprise Mobile Security TLV office, we got our hands on HackRF and hacked together the unguarded boarders of Radio Frequencies. Simone had the great patience to try and explain me the boring world of complex numbers and friends (more on that here), but my dyslexia won over again and left me to fill the gap by following Simone’s steps (and some mistakes, eh Simone? :-) ) and use my ‘trial & error’ approach until success. This tutorial is the result of our collaborate GSM hacking session, presented with the hope it will be useful for others.

You can view Ziggy’s tutorial in this link straight from the Zigperium.

Lantern: A New 925 MHz to 2175 MHz RTL2832U Based SDR for Satellite Reception

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Our friends at RTL-SDR.com are reporting on a new SDR based on the RTL2832u. “It is called the “Lantern” and is being developed for the Outernet project. The Outernet project aims to be a “library in the sky” satellite based service that will provide free access to daily downloads of data such as books, news, videos and other information. It’s goal is to provide people who may not have easy physical or uncensored access to the internet an easy way to access daily information.”

For more information and links, you can find the post on the RTL-SDR.com blog.