BeagleBone LaunchPad Cape

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Initial concept, trying to perfect the silkscreen documentation before sending it out...

 

 

 

Breaks out a 40-pin LaunchPad XL pinout to a select variety of GPIO pins on the BeagleBone's Cape connector so you can play with TI and 43oh community BoosterPacks from the BeagleBone's Node.JS/Bonescript language, or any other language you like to use for that matter.

 

Supports:

UART4 for UART

SPI0 pins for SPI

I2C1 for I2C (I2C2 is the cape EEPROM FYI)

-No EEPROM is included on this since the user is expected to mess with it using Bonescript or load their own custom cape devicetrees for whatever boosterpacks they're playing with.

 

Pinout avoids using any of the eMMC, HDMI or I2S pins.  User LEDs are left untouched too so they do not interfere with boosterpack I/O.

 

Analog 1.8V Vadc is supplied as the bottom pad on the left-side inner header (under the AIN ports).  The GND pin below 5V is connected to AGND to support the AIN functionality.

 

One of the I2C pins happens to also share one of SPI0's pins so it is not jumpered, but the other needs to be switched by a jumper.  From what I gather, SPI0 defaults to D0 = MISO, D1 = MOSI but that can be reconfigured, probably needing a kernel parameter or whatnot.  This is sweet since it allows you to support USI-pinout boosterpacks with only software changes required (to flip the SPI functions around).

bluehash likes this

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Posted · Report post

Touched up & added some images:

 

( '> )

 

( '> )

 

I am going to print this out at home and see how well the footprint lines up with the BeagleBone, I used some specs from the SRM I think to produce that in DipTrace but the proof's in the pudding as they say.  If it lines up, I'll order 10 from Elecrow soon.  Would like to use black soldermask and I think I might for this trial run... would look nice.  Also an opportunity to see if they're still messing up the black soldermask.

 

The 43oh logo is in the top soldermask layer, so it'll appear shiny silver (HASL) against the black background.  I bet it would look gorgeous with OSHpark too but it's $36.70 for a set of 3 boards... lol

bluehash and oPossum like this

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Posted · Report post

I'd say that footprint did me right, lines up perfectly including the gap for the Ethernet jack.  The top left corner stops abruptly to allow viewing of the user LEDs as it turns out.

Submitting an order of 10 shortly.

 

edit: done, $33.04 for a set of 10.

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Posted · Report post

Would be nice if it is in the top post after you finalize it.

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Posted · Report post

@spirilis what exactly would this be for ? I am having trouble visualizing a use case for this. This doesnt mean its useless, just means that so far I am clueless lol.

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@spirilis what exactly would this be for ? I am having trouble visualizing a use case for this. This doesnt mean its useless, just means that so far I am clueless lol.

Quickly prototype hardware with boosterpacks you already have.  I personally see the boosterpack ecosystem as a nice "prototype" platform .... Heck if one were so inclined, they could run the solder reflow system from their beaglebone.

 

Need to try a sensor or 2?  Could breadboard it, but if you already have a boosterpack for it... hell why not use that!  And when you decide the application is probably best done with an MCU instead, just move it over to your MSP430 LaunchPad.

 

Also: Lower-cost replacement for capes -- Capes are big, requiring at least 10cm x 10cm PCB service as I've found.  BoosterPacks can fit into the cheaper 5cm x 5cm footprint.  (And fit other LaunchPads too...)

yyrkoon likes this

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Posted · Report post

Ah ok, that does sound very useful

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Posted · Report post

They look sweet! I can vouch for Elecrow. Cool guys.

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Posted · Report post

Rough fitment looks good, will see how it is once I solder the headers on (lol need to make another big Mouser order too; running low on pin headers and I also received my F5172 LP boards today, another reason to buy more stuffz)

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Posted · Report post

Heh how do you get away with out the verbal bashing from your significant other ? lol yeah very nice man, I'd like to see one / many in action too !

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Posted · Report post

I'd be interested in one of these BTW if they're not already spoken for - great way for someone like me with a bunch of BP's to get started on the BB.

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Heh how do you get away with out the verbal bashing from your significant other ? lol yeah very nice man, I'd like to see one / many in action too !

I control the budget and just give her a fixed agreed amount every month so she doesn't care ;-)

No-shared bank account FTW!  It also helps that I have been getting paid back for some of these things (via 43oh store sales/tindie/etc) anyhow...

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Got one soldered up yesterday, haven't tested it with any boosterpack hardware yet but I'll see about that this week.

 

Also showcasing another project which I'll start another thread about soon.  Don't have any more of them left but have a big OSHpark order on the way for that one...

 

 

First, BBB LaunchPad cape:

( '> )

 

( '> )

 

 

 

 

( '> )

 

 

 

 

 

Second, my solution to the FTDI problem.  A tiny FT230X board that friction-fits the connector and has its USB port angled slightly to allow the USB mini-B cable to slide right between the DC jack & RJ45:

 

 

You'll see one of the BBB LP pics above has this FTDI board installed with the cape overtop, thus allowing you access to the FTDI ttyO0 debug serial port even with a cape installed, thus allowing you to actually investigate issues with your kernel when you install some random cape that screws everything up :-)

 

This FTDI board does not supply power to the BBB btw, so you still need a power source or another USB cable to give it power.  I have an order of USB mini-B cables coming from an aliexpress vendor and I intend to sell the boards with a USB cable for convenience.

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Hmm, another thought I had: For future cape designs I should look into putting a drill hole in the cape right over the S2 button so the user can easily go into uSD card boot mode.  You can usually reach in with a small screwdriver to hit the button from the side, but a hole overtop might be nicer (or maybe you could fit a narrow standoff in there for a better pushbutton...)

 

Also, this cape *should* be backwards compatible with the BBW.  It avoids using any of the reserved/already-used pins of the BBB which should make it compatible with the BBW too.

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Posted · Report post

 

You can usually reach in with a small screwdriver to hit the button from the side, but a hole overtop might be nicer (or maybe you could fit a narrow standoff in there for a better pushbutton...

 

 

Good thinking spirilis. Fat fingers would find it hard to reach that button.

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Been a lazy bum getting these over to bluehash since I'd prefer to send him my F5172 launchpads too in one package... should be soon.  The latter are all built out, just need to test/upload demo firmware & cut some female headers & 32.768KHz XTALs and tape/package them up.

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Well, I'm in for the BBB once you get them out :)  No rush though - doubt I'll have time right away.

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Is that the Elecrow black mask BTW?  Noticed the slight messiness that RobG had around the OSHW logo

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Is that the Elecrow black mask BTW? Noticed the slight messiness that RobG had around the OSHW logo

Yeah I think the problem there is the logo goes over some traces and isn't entirely on the GND plane, so frankly I think it's good they covered up that part cause in retrospect it's not a good idea to expose signal traces unnecessarily like that. Next revision the OSHW logo will be shrunk to fit on that local GND plane area.

Sent from my Galaxy Note II with Tapatalk

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Also want to add something important about the ADC on these things.

 

It's pretty much guaranteed that any boosterpacks relying on analogInput() or ADC functions won't work with this b/c the BeagleBone's ADC doesn't work at the same 3.3V level as the rest of its I/O, unlike the MSP430/Tiva.  It uses 1.8V levels.

 

Its ADC input pins are also dedicated, not shared with other I/O.  This cape exposes them using the inner left header (canonically defined as "analog input" pins per TI's BYOB wiki page) but it should be pointed out that if there are any Stellaris/Tiva/C2000 launchpad boosterpacks that utilize these inner-left pins for ADC functions they might not be compatible with this cape, because they're probably using 3.3V levels for their ADC circuits.  Using those on this cape will burn out the AIN pins on the BeagleBone permanently.  So be very very careful and double-check the schematic of a boosterpack before plugging it in.

 

The 1.8V analog reference voltage is exposed as the bottom-most pin on that inner-left header so boosterpacks specifically targeting this cape can be designed to use that 1.8V reference for voltage dividers et al.

 

All other digital I/O functions especially when using the outer headers (standard MSP430 LaunchPad compatible boosterpacks) should be compatible.

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Had a guy on IRC ask about access to these pics & design files without signing up.  I know @bluehash likes to keep the pics et al restricted to members only, but for "open source hardware" stuff I think this guy has a point... If you have to provide personal information to a website just to d/l the files, is it really "open"?  I think it is, but I can respect the desire not to go through that.

 

So the point here is, I went ahead and reposted the design files & some pics on my webhost and provided hyperlinks in the posts in this thread.

yyrkoon likes this

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Had a guy on IRC ask about access to these pics & design files without signing up.  I know @bluehash likes to keep the pics et al restricted to members only, but for "open source hardware" stuff I think this guy has a point... If you have to provide personal information to a website just to d/l the files, is it really "open"?  I think it is, but I can respect the desire not to go through that.

 

So the point here is, I went ahead and reposted the design files & some pics on my webhost and provided hyperlinks in the posts in this thread.

When the community is small it helps to register to download. If not, then the community would not grow at a required rate. It stays stagnant. Also.. you really don't need to give any personal info. A secondary email id is all that is needed if you don't want to give your personal info.  Info on the forum is free, provided by members. Requires 20 seconds to get registered.

 

In any case, I don't mind if you register or not. He needs to think that there are people contributing and managing the community. One registration helps.

 

Good to know that your board has got some interest.  :D

yyrkoon likes this

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