Hermes-BBB/Botic cape for BeagleBone Black

[Russ White]

Hi Folks,

The module/PCB is available here:
Cronus Reclocking

As promised here is more info on the Hermes-BBB for the Botic driver - it is part of an idea that Miero and I worked together to bring to fruition. Miero wrote the Linux driver/distro side and I worked on the hardware. Together we worked through the datasheets to decide how Botic should work. I am very thankful for the chance to work with Miero on this. It has been great fun.

Hermes-BBB is an open design. I will be sharing the design info (including gerbers etc) as soon as we figure out the logistics and licenses.

Here are some of the features:

• Designed specifically to work with the Cronus - but can work with any other selectable clock source.
• Exposes an isolated clock select output and master clock input.
• Fully isolated audio signal with 1 -8 channels of PCM - 1 - 4 channels of DSD output. All I/O to the Cronus and/or DAC is fully isolated.
• SPDIF output is possible.
• Header for Switches/Rotary encoder
• Header and drivers for indicator LEDs. These can be re-purposed for GPIO via the "FLAGS" header.
• Auto selection of DSD vs PCM routing for DACs that multiplex the LRCK signal with a DSD channel. This means it works well with the BIII-B3SE etc.
• Fully isolated and non-isolated access to I2C for interacting with DACs and other devices.
• Jumpers for either powering the clean side of the I2C isolator from the Cronus or the DAC.
• USART header
• ADC header for analog control.
• Headers for external power/reset switches.
• Prototyping area (for fun!)
• Provision for backup battery to protect the BBB on shutdown by providing a soft shutdown(self regulating battery not included in the kit - but very easy/cheap to obtain).

This module is one of a few Hermes module we have designed to connect directly to a Cronus module which provides the master clock and relocks the audio data to remove any phase noise.

It has been thoroughly tested and works with any audio signal which the BBB can generate. I have tested up to 384Khz 32-bit PCM. Similar data rates for DSD would be no problem.

The isolators can handle input and output in excess of 100Mhz without any issues.

We will be writing a comprehensive setup guide/manual.

It is designed to mate directly with with BBB and the Cronus for excellent signal integrity and no wiring mess.

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Battery Selection

The Hermes comes with a 10K resistor across the NTC terminals for batteries that are self protected against overcharging/current/discharging - LiPo type "062535" (search ebay) are suggested. 250-500ma is more than adequate. This is the only type of battery we recommend!!!

It is possible to use other battery types - but it is not suggested - because the battery manager on the BBB does not protect from undervoltage nor accidental shorts (over current).

Cheers!
Russ

[kinku]

Will this work with Opus and COD ?

[Russ White]

Originally Posted by kinku

Will this work with Opus and COD ?

In conjunction with Cronus. Yes

[dwjames]

Excellent
Some pictures of the final populated board would be great.

Am I right that the i2c port could allow for an lcd display to be hooked up? Is there any provision planned for this in the Botic build?
I was looking to set up a display for the rPi before I swapped to bbb and got as far as finding this nice guide for adding that functionality for rPi /Squeezelite
http://www.thesterk.com/picoreplayer...te-lcd-screen/
which looked fairly straightforward. Could that be added/included with this bbb/hermes/Botic solution?
Thanks,
James

[kinku]

Originally Posted by Russ White

In conjunction with Cronus. Yes

Will there be any limitations with DSD on opus or COD ? Like switches on PCB etc to be adjusted for different PCM cycle signals?

[Russ White]

Originally Posted by kinku

Will there be any limitations with DSD on opus or COD ? Like switches on PCB etc to be adjusted for different PCM cycle signals?

COD will be limited to PCM.

Opus requires configuration for DSD mode via switches/IO or I2C controller.

[kinku]

Originally Posted by Russ White

COD will be limited to PCM.

Opus requires configuration for DSD mode via switches/IO or I2C controller.

Is there any plans to develop anI2c controller if one not available already.😄

[Russ White]

Originally Posted by kinku

Is there any plans to develop anI2c controller if one not available already.😄

The BBB is an I2C controller. It just needs to be programmed to do the job.

[kinku]

Is there any plans from Miero to include in his software?

[Russ White]

Originally Posted by kinku

Is there any plans from Miero to include in his software?

I can't speak for Miero - but anyone could actually contribute such an enhancement.