Secure usb time stamp

Simon Inns created a secure USB time stamp device.

This project implements a USB device which provides a real-time clock for the purpose of time-stamping events in an non-networked embedded computer environment. For embedded applications where a periodic time-stamp is required (such as entry-system logs, configuration audit logs, etc.) it is necessary to have a fairly accurate real-time clock (better than that typically provided by a PC’s motherboard) to generate time-stamps in logging and audit trails. Furthermore, it is preferable to have a method of confirming that the log/audit files have not been tampered with in anyway. The secure USB time-stamp device solves many of these issues in a very small form factor using minimal components

PROTOTYPE: Ethernet JTAG debugger for OpenOCD

We’re releasing a stalled or abandoned prototype every few days while Seeed Studio is on break. We put a lot of work into these projects, but they’re still missing major components and testing. If an abandoned project sparks your interest, we may have PCBs to get you started.

The goal of this project was to make a high-speed Ethernet and USB connected JTAG debugger for OpenOCD. It uses a PIC24FJ256GB106 with USB, and an ENC424J600 100MBPS Ethernet chip.

This project is currently stalled. We grew tired of messing with Microchips gratis-but-not-libre TCPIP stack, and lost interest in developing a new project with it.

Schematic and PCB are on the Ethernet JTAG debugger wiki.


Teflon insulated wire trivia

AkosL writes in with a prototyping tip:

Try teflon insulated wires. (Or other heat/wear resistant insulation materials).  Why?

The insulation is very resistant compared to “common” insulator materials. Both mechanically, and heat resistant (the one right in front of me is rated to temperatures between -60°C to +200°C). You could solder just few millimeters from it for a short time.

Pretty thin too. Not suitable for high currents, but you can push one wire through one hole in a proto-board.

Available in several colors, i have about six colors.

Of course they are not exactly cheap, but not crazily expensive: iirc bought @0.5$/meter.

Read more about Teflon coated wire.

Thanks AkosL! Via the contact form.

Arduino and GSM cellular tutorial – Part 2

Tronixstuff has released Part 2 their tutorial series on using a GSM cellular modem with the Arduino. In this part they cover how to use the telephone network to control an Arduino board via a SM5100B Cellular Shield.

This segment is the latest is a series of Arduino tutorials posted by Tronixstuff.

Microstick dev board for dsPIC33F and PIC24H

The Microchip Microstick for dsPIC33F and PIC24H is a DIP socketed development environment for the dsPIC33FJ64MC802 and PIC24HJ64GP502 16-bit digital signal controller and microcontroller. The board is USB powered with an integrated programmer/debugger, an onboard debug LED, utility LED and reset switch. Pin header spacing is 0.025″. List price is $24.99 from Microchip Direct.

Check out the review at RusticEngineering.

Packet radio and the Arduino Radio Shield

Packet radio is a means of sending data wirelessly over radio channels, and is often used by Amateur Radio Operators. (One form is APRS, described in our earlier post.) In the video following the break you get some idea of how packet radio communications are conducted. The video uses a piece of hardware known as a Terminal Node Controller (TNC) connected between an amateur 2-meter FM transceiver and a computer running a simple terminal program. The over the air protocol used is known as AX.25.

The Radio Shield by Argent Data Systems is an add-on kit for the Arduino development board that provides AX.25 packet radio send and receive capability, a prototyping area, and an HD44780-compatible LCD interface.Packets are sent and received in AX.25 UI frames. This allows operation on the APRS network. Unfortunately, it is not clear that this device is open source. While a schematic is provided, the ID of the U3 chip is omitted. Also, no source code has been released.

UPDATE: Argent has confirmed that U3 is a Freescale MC908JL16CSPE, states they haven’t had a chance to publish the source code yet.

AVRphrase: DIY Catch Phrase game

Zach built his own version of the game Catch Phrase :

When I started playing around with embedded systems, I wanted to do something more interesting than just flashing an LED, and I spent a lot of time trying to come up with project ideas that would be useful (or at least fun) when they were done. One of the first ideas I had was to make my own version of catchphrase. Most of my extended family enjoys the game, but one problem with it is that some of the younger nephews can’t understand most of the words. I thought it would be fun to create a version that they could play, and then the project grew from there.

Thanks Zach! Via the comments.

PROTOTYPE: XT IDE disk controller with CPLD

We’re releasing a stalled or abandoned prototype every few days while Seeed Studio is on break. We put a lot of work into these projects, but they’re still missing major components and testing. If an abandoned project sparks your interest, we may have PCBs to get you started.

The XT-IDE project is a Vintage Computer forum driven project to develop and manufacturer an 8-bit ISA IDE controller. It allows any PC/XT class machine to use modern IDE hard drives or Compact Flash devices for long term storage. (From the XTIDE project wiki)

Our version of the XTIDE controller replaces the 7400-series logic chips with a CPLD, a chip that can be programmed to replace dozens of individual logic chips. The logic is designed in software by drawing a schematic, and then uploaded to the CPLD. New logic circuits can be designed and tested without making new hardware each time.

Schematic and PCB are on the XT IDE disk controller wiki.

Serial port only Bus Pirate v3b

schazamp made a serial port only version of the Bus Pirate v3b:

I have long admired the Bus Pirate, and wanted to build my own. Since I already have an FTDI USB-to-TTY cable, I thought I might replace the FTDI FT232RL subsystem on the Bus Pirate (v3b) with a header for my cable, to save on component cost and board space.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors Adafruit, Open Source Control Systems, and eHaJo.

Via the forum.

Free PCB Sunday: MCP2200 breakout board

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 we’re giving away two PCBs for our new MCP2200 breakout board. The MCP2200 is a new USB to serial converter chip from Microchip. This breakout board brings all the pins to bread-board friendly headers. If you’d like a PCB just ask for one in the comments.

Get the MCP2200 breakout board for $15 at Seeed Studio, read about the design on the wiki.

Continue reading “Free PCB Sunday: MCP2200 breakout board”

APRS homebrew digital radio interface

Automatic Packet Reporting System (APRS) is a digital data communications system often used by amateur radio operators in the 2-Meter FM band. You may hear such data transmissions on 144.390 MHz FM and other frequencies.

DK7IN has published an interesting project which promises to let you transmit APRS data when connected to a licensed amateur FM transceiver and a GPS device. The project uses the PIC 16F84 and a handful of resistors, capacitors, diode and switching transistor. A zip file with source code in Basic and a hex file can be downloaded.

While this project was designed for use with an amateur radio transceiver, there is no technical reason why it couldn’t be used for data transmission on FRS, MURS or other licensee-free frequencies where data transmission is permitted.

Week in (p)review: January 30, 2011

Don’t forget to share your current project in the comments or the forum. This week our favorite project gets a free SOIC protoboard.

Here’s a summary of major developments over the last week:

This week will be full of new stuff:

  • While Seeed Studio is on Spring holiday we won’t have new projects in the shop. Instead, we’re going to release an abandoned or stalled project from our workshop every few days. There will be some clocks, Daft Punk table gear, Arduino shields, and more!
  • We’re waiting by the mail box for two boxes of PCBs. They have the final USB IR Toy v2, a Bus Blaster v2 update, and a couple surprise projects
  • Forum stickies and wiki pages will get a general refresh, and should to point to the latest everything
  • More and more developers are contributing to the Honken USB stack. We expect to do some heavy testing and debugging this week
  • This the first week of the Chinese Spring holiday. Everything shuts down for two weeks. You can still place orders at Seeed Studio, but they won’t ship until February 15th. Need it in a hurry? Try one of our distributors

App note: MAX13450E, MAX13451E RS-485 transceivers

rsdio tipped us to some interesting parts and application notes: MAX13450E, MAX13451E RS-485 Transceivers with integrated termination Resistors

It’s my goal to some day finish a DMX512 dimmer board that I started, based on the PIC16F87 and as many LEDs as can be attached to its I/O pins – next task would be a DMX512 controller with lots of RS-485 outputs…

  • Software/Pin-Selectable Termination Eliminates the Need for External Resistors and DIP Switches
  • Supports Cat-5/Cat-6 and 24-AWG cables
  • Integrated low-voltage logic interface (down to 1.62V) supports small-geometry ASICs and FPGAs
  • Driver fault-indication output (MAX13451E)
  • High ±30kV (HBM) ESD protection and automotive temperature range (-40°C to +125°C) ensures robustness

Thanks for the tip!

Wireless sniffing and jamming

Recently Travis Goodspeed posted an article about using goodfet.cc to sniff radio traffic from the Chronos watch by TI and the iClicker handheld classroom remote.

In addition to the sniffing capabilities, the project can also be used to jam RF signals as well using the IM-ME device illustrated above.

Via Hack a Day.

Arduino-Processing-RFID sandwich game

Here’s a description by joshuajnoble of thefactoryfactory of his efforts in developing a simple “sandwich” game using Arduino, Processing and a Parallax RFID reader. Interesting for newcomers to the hobby as it illustrates the considerations which go into developing even a simple game using Arduino and Processing.

App note: Interface SDRAM and DDR SRAM with a CPLD

irrenhaus tipped us to demo projects that interface SDRAM and DDR SRAM with CoolRunner-II CPLDs:

There is a reference implementation from xilinx how to interface a SDRAM memory from a CoolRunner-II CPLD  XAPP394: “Interfacing to Mobile SDRAM with CoolRunner-II CPLDs” and XAPP384: “Interfacing to DDR SDRAM with CoolRunner-II CPLDs”).

So my idea was: Why not create a small board which interfaces a single SDRAM chip from a CPLD and gives the MCU the possibility to interface it like any SRAM. First parallel but maybe also via SPI or so.

The CPLD they used for the interface to the mobile SDRAM was a XC2C128 with 128 mcells and 144 pins (VFQ144 package) (102 macrocells and 86 pins used). This chip costs about 8Euro @ 1.

For the DDR SDRAM interface they even only used 60 macrocells and 78 pins…

Via the forum.

Vote in the BeagleBoard open source design challenge

Texas Instruments is conducting a design challenge for students at the University of Texas at Austin to determine the most innovative idea implemented on a BeagleBoard ARM Cortex-A8 processor-based system in the form of a practical application.

Ti.com has posted the entries and wants you to vote for your favorite! Voting is open through February 10, 2011.