DIY Onion-Mini-Dock

Kit Bishop

@Daniel-Andrade I would agree that I don't think the A03401 is really needed.

You might also like to consider the use of a TSR 1-2433 in place of the BL1117-3.3
The TSR 1-2433 will give you a regualated 3.3v from any input supply in the range 4.75 – 36 VDC
But I would highly recommend that you still use suitable capacitors across the input and output. See sample circuits in the datasheet for the TSR-1 series which can be found at https://cdn-shop.adafruit.com/datasheets/tsr1.pdf

Daniel Andrade

Hey, right now the project looks like this:

alt text

Schematics and extra docs here:
http://www.danielandrade.net/onion/onion_dock_v0.1.pdf

For 3v3 regulator, I am using a TLV1117LV33DCYR from Texas.
Don't really need so much power from the Traco.

Any extra tips and ideas?

Thanks!!!

fossette

@Daniel-Andrade It's an excellent idea to have the Omega pins available for customized use, and on standard headers to boot.

Daniel Andrade

@fossette Yes, I want it to be Breadboard friendly!

Kit Bishop

@Daniel-Andrade Cool. So basically a form of Mini dock with all the pins exposed for breadboarding/external connections. Great

Leif Bloomquist

This is great! I thought of doing something like this myself, but yours is much more capable. I want one!

Daniel Andrade

Just sent the first board to production.
Going to CES and taking some holidays. I will be back in mid-january.

If everything works I will post here and I can send them to anyone with production + shipping cost

moridin1138

@Daniel-Andrade Please do. I'd be interested!

Kit Bishop

Also see https://community.onion.io/topic/1338/new-omega2-basic-shield-power-ftdi-i2c-and-spi for something very similar

Costas Costas

@Daniel-Andrade any news on your boards?

Kit Bishop

@Costas-Costas @Daniel-Andrade I too would be most interested in any updates on availability of this. Thanks

Luciano S.

@Daniel-Andrade hope it will be available in Brazil too ...

Victor Tagayun

Ist the micro usb acts as USB host or client? I think you should add USB host connector...

WereCatf

@Victor-Tagayun The schematics show the microUSB-port is simply connected to a CP2102 USB-TTL-adapter. It's not connected to the Omega2 itself.

WereCatf

I've never made a single PCB before, let alone used Kicad, but after tussling with it for a day I managed to do my own take on a mini-dock. I skipped on the USB-TTL, because I am going to be using an external one anyways, if needed, nor do I need those reset-buttons, but I did decide to include ESD-protection on the USB-port's data-lines. I also added a header with a couple of extra power-pins, either for powering the device from, or to power any external modules I may want to connect to it.

Ken Conrad

@WereCatf Nice to have another dock option! So, the Omega mounts over the header socket?

WereCatf

@Ken-Conrad No, I figured it'd just about fit under the Omega2, when I solder the female 2.0mm headers, but then I just simply forgot to actually measure it.

Ken Conrad

@WereCatf Worth a measure... I'll advise using at least 805 or 12xx SMT resistors and caps as the smaller stuff is the pits to solder!!

WereCatf

@Ken-Conrad Aye, they are 0805-size. I have practiced some and I can quite easily solder that size, but smaller than that gets a bit too fiddly for me.

Ken Conrad

@Ken-Conrad I understand P1 is power only. If P1 is a micro USB socket then consider instead a mini USB socket as those are easier to hand solder. Since your board is wired to power external stuff, perhaps a higher current (1.1A) regulator like the AZ1117CR-3.3 is a better choice than the ubiquitous 500ma chips.