Seeedstudio Fusion PCB Review

Fusion PCB is a PCB service from Seeedstudio. They have been offering PCB prototyping service since I made my first board in 2011. It has recently been revamped a little, tweaking prices and options, as well as integrating an online Gerber viewer from EasyEDA. I was invited to give Seeedstudio’s revamped Fusion PCB service a try, and since I had some boards in the pipeline for manufacture, I thought why not?

You can configure various options for the PCB, such as board thickness, copper pour and surface finish. You can also make flex PCBs or aluminium for better heat sinking, as opposed to regular FR4. These options will of course come at a price. However, you can select various colours for your PCB at no additional cost.

The Boards

I ordered 2 sets of boards in total. I’ve decided to opt for an ENIG finish for the TIL311 display boards, just because it looks nicer in gold. The boards are manufactured with black solder mask, making the gold pads stand out better.

I’ll describe the display board in a separate post after I’ve assembled it. For now, here’s what 4 of the boards look like, component side up:

TIL311 display PCBs

Like most PCB prototyping services, they track your order by printing some kind of order identifier onto each PCB. Usually they try to put this identifier underneath a component like an IC so it gets hidden when the board is fully populated, but sometimes they put it somewhere prominent, like under your product name. On this board, the identifier sits under IC4 but for the other board, it was under the product name.

The PCBs arrived in a shrink-wrapped bubbly packaging to protect the boards. There was also a desiccant thrown in for one set of the boards to keep it dry.

PCBs arrived in bubbly shrink-wrap

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Designing the X-CTF 2016 Badge

X-CTF 2016 badge with Lithium-ion battery attached

I had the opportunity to collaborate with some NUS students to design the electronic badge for their X-CTF event this year.

The purpose of the badge was to inspire more people to take an interest in hardware hacking, or to get them started on electronics. With so much hype on the Internet-of-Things (IoT) these days, what better idea than to let participants take home their very own IoT device. The super low cost WiFi chip, Expressif’s ESP8266, made this possible. We also wanted it to be shaped like a gaming device, with a D-pad and an LCD.

You can see the final badge design above: a ESP8266-based board with a backlit monochrome Nokia LCD, D-pad and a SELECT button. Powered by a lithium-ion battery, charged via the USB port, which also provides a serial connection to the ESP8266.

I was inspired by the SyScan 2015 badge. It was so simple and spartan: a monochrome LCD, an LED, a 5-way joystick switch and a 32-bit ARM processor (on the back). As the regulator was built-in and it runs all the way down to 2.4V, there was no need for an external regulator.

SyScan 2015 electronic badge

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Circular Layout ULP for Eagle

Some time last year, Mats Engstrom shared his PHP script for generating commands to move components in CadSoft Eagle to form a perfect circle. If you look at the screenshot, it’s mainly made up of MOVE and ROTATE commands – relatively easy.

Eagle has what it calls user language programs (ULPs) for doing some simple scripting with the ability to display a dialog for user input. I decided to try my hand at creating a ULP that creates these circular layouts. The main advantage of using a ULP is that it has access to your board layout, saving you from some typing. You can also easily iterate through different parameters quickly and without hassle.

I shall illustrate briefly how this circular layout ULP can be used for doing various kinds of layout, with help from some open-source projects with Eagle CAD files.

Ringo3 Clock

The most common use for a circular layout is in clocks. Conveniently, Mats has a project called Ringo3. For photos of the PCB and assembled clock, see this Dangerous Prototypes forum topic.

Delete the existing board (.brd) file to start with an empty PCB created from the schematic. We shall take (2.00, 1.60) to be the centre of the circle, as shown. Eagle 6 introduced a dimensioning tool, used here to show the radius of the circle (1.5″) – handy but not a must.

Ringo3 empty PCB layout

The circular layout ULP has 3 main sections: (i) parts selection, (ii) layout options, and (iii) circle centre point & radius. For parts, enter D for prefix and 1 to 60 and click the Filter button to select components D1 – D60 for layout. The handy table shows you the currently selected list of components. Enter 2 and 1.6 for the circle centre X, Y values that have been identified. The radius has been marked by the dimensioning tool as 1.5. The layout direction is “Clockwise” and we want to place D1 at the top “12 o’clock” position. Click the Do Layout button, and OK to start the layout.

Circular Layout Settings

You should see the components move into place as shown in the next figure.

Ringo3 PCB with laid out LEDs D1 - D60

If you make a mistake, you can always just hit Undo or hold down Ctrl+Z until all the components were back at their original positions.

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Coloured iteadstudio PCBs

Good news everyone! iteadstudio is offering coloured PCBs at a lower cost.

After I had my very first set of PCBs manufactured, I was thinking of making my next set of PCBs in a different colour. However I found the price difference to be quite big and might just stick with plain old boring green instead.

Now that they’ve announced their new offering, I’d definitely go for a different colour for my next batch. They’ll be offering 8 boards instead of 10 (which is not a problem at all for me), and fixed thickness of 1.6mm and HASL finish – all for an extra US$5 more than their base PCB service. Their available colours are blue, white, yellow, red and black.

[via Dangerous Prototypes]

iteadstudio PCBs

This is my first try designing and fabricating a PCB, so I decided to use iteadstudio.com since they are the cheapest available – US$12 for 10 pieces of the same 5 x 5cm board.

I tried my best to make the design error-free because I didn’t prototype the circuit first (not really a good idea). I’m still waiting for the components to come in, so I can’t tell if there are any problems yet.

I sent the gerbers, and they shipped the order in about 7 days. It arrived after 2 weeks (not sure if they were clearing the backlog from Chinese New Year).

A couple of things to note:

  • the silkscreen is white (on green) despite the site claiming it is black
  • the board will be routed to your outline

It was said that seeedstudio uses the same board house, so I used the DRC file and the CAM job file available in their web store where they offer the Fusion PCB service. The DRC helps you ensure that the board meets the fab house requirements. iteadstudio does not provide any such files. As the CAM file description states, the drill holes will not line up with the other layers, but the board house seems to have no problems with it.

Boards that are E-tested will have a marking. This marking can be seen here on the top edge. Oddly only 4 boards are marked, even though the site states that 5 boards will be tested.

Here are the front and back of the PCB. The silkscreen is slightly skewed, as you can see from the IC3 rectangle. I designed the PCB shape to fit into a case I bought locally, which unfortunately did not have any technical drawings. The good news is the board fits in perfectly.

The vias are all 0.4mm and were tented. I thought this was an error, but I re-checked the design and found that the seeedstudio DRC will not generate a soldermask stop for holes smaller than 100mils.

I love the QR code – it looks really nice against a green board, though I think it would look even better on red (like SparkFun boards) or blue (like Arduinos).

I will talk more about what this board does, as soon as I assemble and test it.

Update 12-Mar-2011: Apparently Dave Jones has also used their services and they mucked up his board by reducing copper pour around holes.  He talks about the problem in episode #155 (skip to 9:20 mark).