Sent off a CircutMaker PocketBeagle Cape, Would appreciate any feedback

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1

Hi Folks,

I tossed together a pocketbeagle cape using Circuitmaker last week… After I get my protos back I was planning on fixing any mechanical issues I have and creating a pocketCape template project like the BeagleBoard cape template that I’ve used several times.

If anyone wants to take the time to look and provide some constructive criticism I’d be happy to hear it as I’m sure I’ll be rolling the board anyway, this one was tossed together fast.

https://workspace.circuitmaker.com/Projects/Details/David-Lowe-2/PocketBeagle-Automotive-Cape

And I have a couple of questions:

  1. I added the I2C eeprom that we use to support the device tree overlay support for the BeagleBoard. Is this facility going to work on the PocketBeagle? It seems the BBB support has been hit and miss over distro updates.

  2. I had a hard time finding current requirements of the PocketBeagle, Can someone point me to the consumption data?

  3. Can someone that has Eagle installed send me a real mechanical drawing? I made mine from empirical measurements and have noticed that it’s lopsided but may still mate ok with the pocketbeagle

Thanks in advance!

Miller

2

Hi Folks,

I tossed together a pocketbeagle cape using Circuitmaker last week… After I get my protos back I was planning on fixing any mechanical issues I have and creating a pocketCape template project like the BeagleBoard cape template that I’ve used several times.

If anyone wants to take the time to look and provide some constructive criticism I’d be happy to hear it as I’m sure I’ll be rolling the board anyway, this one was tossed together fast.

https://workspace.circuitmaker.com/Projects/Details/David-Lowe-2/PocketBeagle-Automotive-Cape

Based on what you want to accomplish, have you looked at https://docs.macchina.cc/pb_adapter/ ?

And I have a couple of questions:

  1. I added the I2C eeprom that we use to support the device tree overlay support for the BeagleBoard. Is this facility going to work on the PocketBeagle? It seems the BBB support has been hit and miss over distro updates.

The overlay support in the BeagleBoard.org Debian images has been migrated to u-boot for BeagleBone (Black, Green, etc.). As of now, PocketBeagle does not do the EEPROM reads for overlays, but we’ve got a couple of PocketBeagle capes in the works that will indeed include EEPROMs (always at offset 0x57, but potentially on either I2C port) and I’m looking to add the same EEPROM scanning logic for PocketBeagle (but only for offset 0x57, yet for each of I2C-1 and I2C-2). There’s a chance I could have some objections, but that is my current thinking.

  1. I had a hard time finding current requirements of the PocketBeagle, Can someone point me to the consumption data?

You are primarily just looking at the consumption of the AM3358, DDR3 and microSD card, with some efficiency loss in the PMIC. There is a very small efficiency gain through use of the SIP (less capacitance on the DDR I/O lines), but you can ignore it. You can look at something like http://processors.wiki.ti.com/index.php/AM335x_Power_Consumption_Summary#Mpeg4_.2B_AAC_Decode to give you an estimate. I feel pretty safe estimating under 1.25W (or 250mA @ 5V), but that’s probably still a bit too conservative if you don’t have any I/Os hooked up.

  1. Can someone that has Eagle installed send me a real mechanical drawing? I made mine from empirical measurements and have noticed that it’s lopsided but may still mate ok with the pocketbeagle

There is a .STEP model at pocketbeagle/models at master · beagleboard/pocketbeagle · GitHub.

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Thanks For the answers!

I knew about the uboot overlay but have not played with it yet, I added the EEPROM from older BBB capes in a copy-paste mode…

Is there any documentation on how to setup the uboot overlays? Just as a starting place for when I get back around to it.

I got my boards back, I’m slightly off on the overall dimensions but the stacking connectors line up nicely.

Like everyone else I had some challenges getting cheap stacking connectors but I’m low volume, 40 pin stacking connectors and a few seconds on the belt sander was cheaper to make them fit than finding skinny replacements.

Miller