Mar 16

PCB advice and fabrication

This post is about PCB (printed circuit board) services and full-fledged PCB manufacturing. You can etch your own one sided board (double sided boards are possible. There's a tutorial by BlondiHacks showing you how), or you can purchase them from a PCB service. Here's a list of PCB services and some advice on making your own PCB's. I will use a 2"x3", 2-layer pcb for my pricing comparisons.

Fusion PCB Service from seeedstudio: They have a minimum quantity of 10 boards, and use cm instead of inches. A 5cm x 10cm (50 cm^2 opposed to 38.71 cm^2 for a 2"x3" board) PCB costs $2.39 per board.

OSH Park: Formerly DorkBot, this Open Source Hardware company offers 2-layer PCB's for $5 per square inch for a quantity of 3. That means it's $10 per board for a 2"x3" board (you have to order in batches of 3, so you get three 2"x3" boards for $30). If you order over 150 square inches, it's $1 per square inch, or $6 per board. They use Eagle as their CAD software. Their boards look good (I think silk screening is included, but I'm not sure).

Futurlec PCB Service: Futurlec has a PCB service. There is a $25 setup cost per run, but for a 2"x3" board, it's $3.1 in quantities of 100 and $3.8 for 1. They can also do solder masks and silk screening. With silk screening and a solder mask, it's $3.71 for 100 boards.

Fritzing Fab: They charge by cm^2, which means that I have about 38 cm^2 for a 2"x3" board. Even in quantities of over 200 cm^2 (about 5 boards), it's $20 per board. They are a lot more expensive than the other suppliers. They use Fritzing though. (for over 10, it's around $17).

PCB advice: Here's a blog about making PCB's for pick and place machines to pick and place onto. It also has other PCB information that you could use.

Outsourcing PCB manufacturing:

Ch00ftech has an article about outsourcing the manufacturing process for PCBs entirely. It covers using Myro, a Chinese manufacturing company, to make the PCBs and assemble them. It covers a lot of good information if you don't want to hand solder a whole bunch of boards.

Seedstudio also has a service where they manufacture the PCB's and put all of the components on them. They have you purchase the materials for them (and have them sent there), but it's another option instead of just looking at Myro.

Mar 16

Pick and Place Machines

If I want to manufacture boards on a small scale (say I build a laser tag or gps puzzle box board and want to make a few. Like 100), and I don't want to solder them all by hand, then I'll need a business partner or a pick and place machine. Since doing it myself will be cheaper and potentially more fun to learn, I've looked a bit into pick and place machines. Since I'm trying to keep costs down to as low as possible, I'm looking into DIY or other low cost alternatives. I found a few pick and place machines on the internet, and here they are (this is not exhaustive. It's just some cool things I found).

Open Source Pick and Place:  This is an open source pick and place project. They use a raspberry pi as the processor and they are trying to get the machine to cost around $2000. They're trying to do a kickstarter come summer 2013.

Dangerous Prototypes blog: TM220A: This is a chinese pick and place machine that does not do any vision processing (aka, doesn't auto correct by looking at the parts and the board to see if it is placing things correctly). It is around $3600.

Hoektronics meet a Shenzhen Maker: This is a cool article about a person who wanted to learn about pick and place machines and went to see someone who has his own fabrication lab in his house. It's a neat article. The guy who runs the blog, Hoektronics, also has some other cool projects, like the blinkyboard, an Atmega 32u4, which is the same processor that is in the arduino Leonardo (the blinkyboard is made to control LED strips).

Build a Pick and Place Machine: The guys from build your own CNC machine have made a pick and place machine for DIY enthusiasts to build. It's around $3700 and requires a good amount of knowledge to assemble it. Which means more time I'm spending putting a machine together instead of making parts.

Pick and Place Assistent: This one isn't an automated pick and place machine, but it does look like a handy tool to help with picking and placing components by hand. It's about $100.

However, in order for a purchase such as this to be a good idea, I need to make a case that the time saved using the machine outweighs the time I would have spent making the darn things by hand. Therefore, before I dive in, I need to clearly estimate the number of boards I will be making (aka actually building the product and testing it out) and do a cost benefit analysis before I get the machine. In the meantime, this is notes for me for the future, because knowledge is power. And power is Voltage times Amperage.


Mar 15

RFM12B Wireless Modules

Over the months, I've ran across a number of wireless modules, each telling me different things about their capabilities. There's the XBee, a great module that has books written to teach people how to use it. They come in many flavors and have a lot of breakout boards. They are also $17 for the low power version or $28 for the Xbee Pro, according to Then there's the Nordic nRF24L01, which is a low cost module with an arduino library. They cost $4.75 (on sale now at for $2.75. Nice) Lower cost, but more difficult to set up for the beginner (there are code samples, people have used these before).

I recently came across the RFM12B. It's $6.95 at Sparkfun, but I doubt that's as cheap as one can find them, since Sparkfun usually is a bit more expensive than other suppliers (I have nothing against them. They were one of the first suppliers to carry arduinos, and I appreciate that. I also look for bargains). It also has a library (created by Low Power Lab based on the JeeLabs RFM12B library), which is completely open source (MIT license, so the code that uses it must also be open source, but since my project is open source too, that doesn't matter). Not sure whether or not it will be easier to use than the nRF24L01, but it's worth looking into if I make all the laser tag modules use RF to communicate hits to a central hub. That'll happen later in the process, after the core functionality is ironed out. Potentially, IR communication could be all I use for my open source laser tag project (note, OpenTag is a  DASH7 protocol stack, which is an open source wireless network standard. Damn. Can't use that name), so I won't need to have a wireless module on the units.

Note: the guy over at Low Power Lab is manufacturing an arduino clone with a RFM12B wireless module called the Moteino. He has some videos about soldering the Moteinos  (along with the stencil he uses to apply the solder paste) along with the iTeadStudio PCB's that he's using. Check out his blog at

You can also build a DIY laser cutter that can cut stencils. The tutorial is here.