Slashdot Mirror

Did you try https://oshpark.com/ ?
20x40mm = 800 square mm
800 sq mm = 1.240002 sq in
USD$5 per square inch = USD$6.20$

But that's for three PCBs, so that's only USD$2.07 per PCB. Yes it's more expensive than the 80 cents PCBs from China, but it's not 262 times more expensive. And OSHpark ships for free, all over the world.

I could also give you quotes from other USA-based PCB manufacturers which are all well below USD$210 per PCB. You probably went to one which isn't "maker-friendly".

Generally, on a mass-produced board, it is real gold. But only on permanently exposed connectors, like the fingers for the PCI-e socket, and in an extremely thin layer. Literally nanograms of gold per board. If the board is going immediately to population and soldering, they won't bother doing that to the device pads.

Some small-run boards are done with ENIG too. OSH Park, for example, does Electroless Nickel Immersion Gold with purple solder masks. Looks fantastic and has a long shelf life.

Gold is still very important in places where people need a visible display of wealth. India's upper middle class, I'm told is one example. Lower middle class who aspire to move up tend to buy, but don't display it as much. Again, so I hear.

I second OSH Park.

https://oshpark.com/

We bring you high quality, lead free boards (ENIG finish), manufactured in the USA, and shipped for free to anywhere in the world.

Can't beat that!

Wish I'd come across this earlier. I've been developing a Raspberry PI hat circuit over the last six weeks and it's been a steep learning curve since I'm not a circuit nerd. Doubtless all the circuit nerds here will find that article overly simplistic but I'm a code monkey and had to piece this together from a number of other tutorials over the last six weeks. The things I have to add is really only the observation that Eagle Cad is the most counterintuitive piece of software I have ever tried to use. I decided to do a schematic and convert it into a PCB using Eagle which worked well enough. However, I have used any number of circuit simulators (eventually selected a href="http://icircuitapp.com">iCircuit, nice simple and available for: OS X, iOS, Android and Windows) and the UI in all of them much worked pretty much the same way but it's like Eagle Cad's developers went out of their way to make the UI of their schematics editor different. That said, Eagle Cad works like a charm one you figure out how the UI works. The component libraries can also be pretty overwhelming. After a lot of searching I came across this PCB prototyping service. No generating Greber files, just hit the "Get Started Now." button, upload the Eagle CAD file and pay the man, $18 for three boards and free shipping, turnaround time is c.a. 3 weeks. I'm still waiting on the boards so I can't judge their quality but I loved the simplicity of their site and I really hope their work is as good as people say it is because the pain of figuring out how to generate Gerber files in Eagle is bound to be as counter intuitive and painful to learn as everything else with Eagle.

Thankfully the Internet Archive crawled the page before HAD redacted it.

Here's the original:

Tektronix’s MSO2000 line of oscilloscopes are great tools, and with the addition of a few ‘application modules’, can do some pretty interesting tasks: decoding serial protocols, embedded protocols like I2C and SPI, and automotive protocols like CAN and LIN. While testing out hisMSO2012B, [jm] really like the (limited time) demo of the I2C decoder, but figured it wasn’t worth the $500 price the application module sells for. No matter, because it’s just some data on a cheap24c08EEPROM, and with a little bit of PCB design it’s possible to build this module for under $5.

The application module Tektronix are selling is simply just a small EEPROM loaded up with an SKU. By writing this value to a $0.25 EEPROM, [jm] can enable two applications. The only problem was getting his scope to read the EEPROM, a problem easily solved with a custom board.

The board [jm] designed is available at OSH Park, with the only additional components needed being an EEPROM, a set of contacts for reading a SIM card, and a little bit of plastic glued onto the back of the board for proper spacing.

And Jm's post:

I purchased a new Tektronix MSO2012B Oscilloscope and quickly found utility in the demo I2C decoder for when I need to diagnose the failed controller in my hot tub. Before the demo period expired, I decided that the capability was rather compelling but didn't have money to purchase the actual application modules. This scope is used purely for hobbies and will never make a buck. After scraping the internet (and Google Translate) for information about this scope, I was able to produce my own Application Modules. It was a whole lot easier than I expected it to be.

After some investigation and trial/error I found that each application module can be enabled with up to two applications by writing the SKU of the application module (SKU can be found on the Tektronix website) onto a 24c08 eeprom.

Once this was proven, boards were created at OSHPark, a few parts purchased from Digikey and I now have a rather capable device.

For reference, dumps of the 24c08 are provided along with a part list to recreate this and my open source board published on OSHPark

1x Haktek Module ($3.00) - https://oshpark.com/profiles/m...
1x 24c08 ($0.25) - Digikey - 24LC08BT-I/OTCT-ND
1x Sim holder ($1.50) Digikey - 609-1401-1-ND
1x Spacer - Free

The 24c08 goes on the back of the board while the SIM holder will need to be trimmed to fit onto the board. Program the 24c08 by any means you have. I used a spare RaspberryPi. The I2C header to write to the module is labeled on the PCB.

To make it fit in the Tektronix, use a spacer to fill the gap between the PCB and the module bay. I initially used a piece of paper folded up but eventually found a scrap piece of plastic and glued it on.

What amazed me about this was Tektronix used no encryption, hashing or any other forms of authentication. It's just an EEPROM and for under $5 I was able to enable functionality that was not initially exposed. This shouldn't even be considered hacking. It's synonymous to flipping a bit in a configuration file.

Please comment below if this same methodology works with other Tektronix scopes.

Thanks!

- Jm

And the board design

The Google cache was taken down. The original author seems to have agreed to take down the information on his site as well, even without having been contacted him-self:
https://sites.google.com/site/...

However, they were too late. The web archive has already archived their pages. Here are the relevant links:

http://web.archive.org/web/201...

http://web.archive.org/web/201...

(not modified)
https://oshpark.com/profiles/m...
http://web.archive.org/web/201...

That covers monitoring. Throw in a couple of servos and drivers to control the ventilation and you have a complete system. Drop the Pi/Arduino combo and use a Beaglebone Black and you keep roughly the same expenditure.

I think I have a project lined up for the holidays...

[ By the way, it had been a little while since I last used BatchPCB, but they've since sold their operation to OSH Park, who now does all of the fab work in the US and the turnaround is much quicker. If you're looking for reasonably priced small batch PCBs, check them out. ]

Some services start even cheaper than $28. For example, OSH Park.