Raspberry Pi 2 and 3 "Steve" Trim

[The Save State Gamer]

The idea of a Raspberry Pi board trim has been thrown around on BitBuilt before, but due to the lack of Raspberry Pi activity on BitBuilt, no example of a successful trim has ever been released. Taking this trimming idea in mind for my upcoming Raspberry Pi 3 portable "Game Brick", I decided to complete a simple "Steve" trim that would remove unused features, while not breaking any necessary traces. Additionally, I removed all connectors except for the HDMI port.

Just so that everyone knows, this trim removes the screw post part of the board, the networking jack vias, the GPIO, and the additional space around the USB ports. As shown below, Raspberry Pi 3 on top and Raspberry PI 2 on bottom.

 

[fibbef]

Anyone know if the Pi is a multi-layer board? Seems the obvious way to trim further would be to hack off the USB pads and rewire somewhere closer to the cpu.

 

[lyberty5]

Wouldn't using a pi3 compute module and building the features you need around it end up smaller? (only USB and HDMI for example) or are they radicaly different?

I've been toying with this idea and when looking at the CMIO board, it seems HDMI and usb ar just a few components and traces away and could be soldered directly to the pi CM 3.

Just a thought...

Also, I can't find where I read that information but I do think the pi3 is a 4 layer board. 50% sure.
I'm sure a side view of the trimmed board above can answer that question.

 

[The Save State Gamer]

@fibbef : The USB data vias and the networking jack vias are actually connected to a controller chip that is then connected to the CPU. This controller chip is on the front side of the board just back from the USB vias, and the traces for the USB and networking data lines are on the top side of the board along with this chip. If I trimmed off the USB vias, I suppose I could scrape the board and solder to the traces or solder directly to the controller chip, but I would like to avoid both of these tasks. And yes, the Raspberry Pi is a multi-layer board, but I am unsure how many layers there actually are. (The Raspberry Pi 1 was a six layer board, but I could not find this information for the 2 and 3 as shown in my original post.)

Using the compute module as @lyberty5 described is not a bad idea, but it is more difficult than trimming the Pi 3 board, and this difficulty is not justified due to the minimal return in saved space that it would give, as the compute module is already a good chunk of the Pi's size. Additionally, the compute module lacks bluetooth and wifi, so I would need to wire up USB adapters for these as well, as my design relies on these features. In the end, the additional cost for the bluetooth and wifi adapters combined with the added difficulty and minimal return in space makes using the standard Pi 3 with a board trim the logical solution.

Edit: I forgot to add that schematics (not board layouts) for the Raspberry Pi boards are available online HERE. Using these schematics, I was able to find test points for all of the voltage outputs from the Pi's initial voltage regulation systems. This data is useful for me particularly because the screen I ordered runs off of 3.3 volts, one of the Pi's voltages. (I will link the screen with more data later if someone asks for it.)

 

[lyberty5]

I've found this :
https://blog.adafruit.com/2016/03/02/pi-3-x-ray-raspberry_pi-raspberrypi-pi3/

Maybe it's obvious or of no help for you but I thought of this thread when reading this.
Between both sides of the scan you can basically see all the layers.

 

[ComradeNull]

I don't want to revive a dead thread by a banned user, but I think that the following information is pertinent.

In my Raspberry Pi 3 adventures, I accidentally broke off of the board one of the components near the transmitter; I think it was a resistor or capacitor. The missing component caused the Pi 3 to fail to boot, so I trimmed off the corner of the board with the transmitter. After sanding the cut edge, and making sure not to cut any CPU lines, the Pi 3 booted right up. So, in conclusion, the transmitter can be trimmed off too, and I just wanted to add that.

 

[GuiBacon]

Hi...rhe Raspberry Pi uses a multi-layer printed circuit board so there may well be important signals running through that portion of it. Layer drawings have not (and will not) been published so you're not going to get an authoritative answer. One perspective is that it might only cost $35 to find out for certain.
Some people have removed unused connectors to lower the board profile.

turnkey pcb

 

[cheese]

Layer drawings have not (and will not) been published

orly
https://bitbuilt.net/forums/index.php?threads/raspberry-pi-zero-v1-3-full-scans.2221/