A new open source hardware project every month
S3C used the Bus Pirate SPI sniffer mode to decode output from a serial magnetic card swipe reader. More at S3C’s site, and in the forum.
Regular Demo: articles will return next week. Demo: is a weekly series that demonstrates devices with the Bus Pirate. Come back next Monday for another new demo. Continue reading the demo below.
Tags: mag stripe, magnetic card
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 professionally-made PCBs from one of our past or future projects, or a related prototype.
This is a USB controlled RGB color changing light. Someone made some minor modifications to the design and had a bunch of boards produced, we ended up with a pile of the extras. This PCB is as-of-yet untested, you can discuss it in the forum.
We’re giving away two PCBs this week, just ask for one in the comments.
Tags: giveaway, rgb color changer
The web platform EEPROM and SD card server firmwares have stability problems at full speed, we encountered this bug with the @tweet_tree. Markus Gritsch posted test firmwares that have now been running for over 72hours without interruption. They even work when the PIC and SPI interface are overclocked beyond the datasheet specifications.
A single edit to the Microchip TCPIP stack seems to have fixed stability issues, but it’s not quite clear why as the SPI settings should now be incorrect. We’ll post an update after we run the current and updated firmware under debug.
There is also a partial port of the open source uIP TCPIP stack in the SVN. It’s still a work in progress.
Tags: enc28j60, Microchip TCPIP stack, PIC, spi, uIP
Bert tipped us to the Sigrok open source logic analyzer client. Sigrok is a multi-platform client that aims to support most common logic analyzer hardware. It currently only supports the Saleae Logic, but Open Logic Sniffer support is in progress.
Preorder an Open Logic Sniffer for $45, including worldwide shipping. The OLS should start shipping in April.
Tags: Open Logic Sniffer, open source, Saleae Logic, Sigrok
scj made a wiki about using the Bus Pirate with Arch Linux. It covers creating a udev rule to name the Bus Pirate /dev/buspirate, and communication with minicom, screen, and picocom.
Thanks for the tip!
In the summer of 2009 Ian Lesnet setup a Bus Pirate v2go preorder as a fundraiser for Hack a Day. It was a lot of fun, so he started Dangerous Prototypes. We’ve done one preorder project per month since September 2009. There might be readers who didn’t follow the Hack a Day preorder, so we wrote this post to explain the process. If you’ve participated in a preorder, there might still be some interesting behind-the-scenes info about how your hardware was made.
We’re open source hardware and software enthusiasts who like to make stuff. We don’t have our own pick and place machine, and we don’t assemble kits, but you can get a copy of our projects at Seeed Studio. When you buy a copy of our project at Seeed, they kick a few bucks back to us so we can make more open source stuff.
We’re proud to work with Seeed to make our open source projects available to everyone. When there are cheap rapid prototyping machines you’ll be able to print our projects at home, until then, there’s Seeed Studio. Seeed has inexpensive worldwide shipping starting from $2.85, most of our projects include shipping in the cost.
Lots more about the preorder process below.
Tags: process, Seeed Studio
Double sided home-etched PCBs require a lot of patience and luck. Both sides need to be aligned properly, and via wires have to be soldered between the layers so top and bottom are connected.
The usual process for connecting the layers is to insert a small wire in each via hole and solder it. This is a tedious, time consuming process. YourITronics documents another way: thread a long wire through all the holes, solder it in place, and cut away the excess. The result, as seen above, is a very small, very clean via connection. There’s even a few under the TQFP chip! We’ll definitely use this tip the next time we make a double sided board at home.
Tags: etching, fabrication, vias
nada demonstrates how to initialize, read, and write an SD card with the Bus Pirate SPI library. Don’t miss the GPS logger project that the SD card went into.
Get your own assembled Bus Pirate v3 for $30, including worldwide shipping.
Via Hack a Day
There is an unconfirmed report that the first USB IR Toys will ship today. We’ll update when we hear more.
The USB IR Toy is currently listed as sold-out at Seeed, we’re working on continuous stock.
Tags: unconfirmed
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 professionally-made PCBs from one of our past or future projects, or a related prototype.
This is a USB controlled RGB color changing light. Someone made some minor modifications to the design and had a bunch of boards produced, we ended up with a pile of the extras. This PCB is as-of-yet untested, you can discuss it in the forum.
We’re giving away two PCBs this week, just ask for one in the comments.
Tags: giveaway
The OpenOCD project accepted Michal Demin’s patch that adds Bus Pirate support to the popular open source JTAG debugging client. Read the tutorial here. Congratulations Michal!
The Bus Pirate is a topic on Adafruit Industries’ “Ask an Engineer” chat tonight at 10pm ET. If you missed it, they keep previous chat videos in the Adafruit forums.
Tags: Adafruit, ask an engineer
USB IR Toy
The USB IR Toy is back from manufacturing and is being prepared to ship now. Parts were ready before the Chinese Spring holiday, but then things stalled, Seeed moved, and they’re about two weeks behind. The good news is that our packages from Seeed are now arriving in less than a week again. There should be a continuous stock of IR Toys available after the preorders ship.
Open Logic Sniffer
Parts for the Open Logic Sniffer have been ordered. The PIC 18F24J50 ICs will arrive from Microchip Direct on March 18th. Approximate lead time (assume delays) will be three weeks from then.
Bus Pirate
The latest Bus Pirate preorders should all be shipped. The Bus Pirate should be in continuous stock from now on. You can also pick one up at Adafruit Industries.
Our commitment
You’ve been so patient with our constant delays, availability problems, hardware defects, and all the other foibles of small-run open source hardware manufacturing. We’re trying several ways to improve the process from our end.
We’re learning to design for the situation. We’re checking and doubling checking part availability before a chip goes in a project. Our priority used to be ’sampled or recycled’ (see the awful RS232 transceiver on the first Bus Pirate), but now it’s ‘10K+ available’.
Some part and PCB orders are now placed before a project is published. This helps reduce lead time and lets us spot show-stopper problems before we go public. The flip side of this is possible shortages for some projects because we’re nervous about committing to a lot of stock.
Project tracking
Each preorder has a status update thread in the forum. We’ll post every update we get, so you can see exactly where the preorder is at. If you’re registered at the forum click ‘notify’ to receive the latest updates by email.
After a few months we’ll study the status updates and design a report page to give statistics on each preorder.
Tags: manufacturing, Seeed Studio
Adafruit Industries now has the Bus Pirate and probe cables in stock and ready to ship. This is the same gear you get at Seeed, but it ships from the US today. Every Bus Pirate sold at Adafruit contributes to further development of the project.
This is our first distribution deal, and it’s really exciting. A special thanks to Adafruit for putting up with our noobness and funky supply chain. We’ll have a “how-to” writeup about the distribution experience soon.
Thank you for supporting this project and making it a success.
Tags: Adafruit, distribution
There’s no update from Seeed about a custom Open Logic Sniffer cable, but Sjaak recommended a few other options from Seeed:
You can pick up an assembled Open Logic Sniffer at Seeed Studio for $45, including worldwide shipping.
Tags: cables, probe cable
Markus Gritsch added a USB power supply jumper to his web platform:
I found it convenient to be able to power the Web Platform using my iPhone USB charger and a normal USB cable. It is also convenient when presenting the board to friends and powering it using their computer. Therefore I soldered a pluggable (via two DIL socket pins) connection from the USB power to the 3.3 volts regulator (picture attached). I measured the consumed current which is about 200 mA, so when powering no additional hardware with the Web Platform it should be ok for most USB ports.
In a future revision of the board maybe a switch could be added to choose the power source, similar to the solution on the Seeeduino.
You can buy an assembled web platform for $40, including worldwide shipping.
The forum migration is complete. You can now access the forum at http://dangerousprototypes.com/forum. All links to the old forum at whereisian.com should forward correctly to the new address with a 301 redirect.
Accounts are all the same, and all the attachments were transferred. There is a bug with attachment thumbnails, but we’ll try to get that worked out soon.
Please let us know if you notice any bugs or issues. Thanks for bearing with us during the changeover.
Tags: forum
Update: migration is complete. You can now access the forum at http://dangerousprototypes.com/forum.
The forum will be migrated to http://dangerousprototypes.com/forum starting in a few minutes. Both forums will be locked while we migrate the latest posts. Links to the old URL should be automagically forwarded to the new address.
Tags: forum
If you see this message, you’ve landed at our new digs at Laughing Squid. More free PCBs for the first couple commenters, help us test the new install by leaving a comment.
Tags: giveaway, laughing squid
Choosing a substitute electronic part
March 13, 2010 in components, skills | No comments
Choosing substitute electronic components is a common snag for beginners. What do you do if you can’t get the exact part used in a project? Part finder posed this question about the USB IR Toy:
This component is hard to find from my local store: D1, Small signal diode (DO323, BAS16HT1G, Rectifier 85V/0.2A Small Signal Diode).
Can I replace it for example with [this]?
What are the important values?
We didn’t give a particularly helpful reply, but Brian Willoughby picked up the slack with this fantastic description of how to pick a substitute part:
The most important value is the DO323, a.k.a. SOD-323. As Ian says, you can’t easily squeeze a different shape onto the PCB.
What I always do is hit Mouser. Start with a search for BAS16HT1G, and when you click on the Mouser part #, you’ll be given the opportunity to search for similar replacements. In this case, Mouser uses SOD-323 as the package / case. You can basically turn off the checkbox for everything else, because you don’t care about brand or other overly specific values. In the results that appear after clicking “Show Similar,” I tend to sort by price and then start narrowing down the options. Mouser finds about 425 options that would fit the PCB.
The actual selection process can be a little tricky. I recommend keeping a browser window open on the original part, and then use it as a guide to narrow things down in the search results. For example, after selecting general purpose diodes in the search results, I see recovery times of 4 ns, 6 ns, and 50 ns. Since the original part is 6 ns, I just select 4 ns and 6 ns to weed out the slower 50 ns diodes, just in case speed is important. Meanwhile, the lowest voltage is 70V and the smallest current is 150mA, so probably anything will do. If you’re concerned, then start specifying more values to narrow the results.
You’ll note that there is a 1N4148 in SOD-323 as part of the results.
If you want to speed up the process, the Mouser part # page for the original part will update the number of similar parts Found as you check or uncheck different specifications, so you can quickly experiment with how precise you want the match.
Great description of a tricky process, thanks Brian!
CC-BY-SA image by sparr0.
Tags: comments, parts, substitutions