Is it possible to connect the Hermes to another recloker isolator, or it does not make sense?
Forgive my ignorance, I am from the analog era.
Forgive my ignorance, I am from the analog era.
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Hi Russ and Brian,
I have now stumbled upon a new challenge in my quest for automatic DSD-PCM switching on a Dual Mono build 🙂
I need to switch IIR Bandwidth form Normal to one of DSD ones.
I see several options and questions here:
1. Use flag pins on Hermes to switch those switches on BIIISE by setting External I/O connector's pins (B6 and B7) to high or low.
The question is - is this going to work? i.e. if I set B6 to high (3.3V), it will mean it is closed, right?
2. Use Miero's script for setting basic DAC registers.
The question is - how to connect isolated i2c to Dual Mono BIII's? Just by paralleling the wires?
3. Set IIR Bandwidth to 70K via switches on BIII board, no matter what is playing 🙂
Please advise.
Thanks,
Fedor
I have now stumbled upon a new challenge in my quest for automatic DSD-PCM switching on a Dual Mono build 🙂
I need to switch IIR Bandwidth form Normal to one of DSD ones.
I see several options and questions here:
1. Use flag pins on Hermes to switch those switches on BIIISE by setting External I/O connector's pins (B6 and B7) to high or low.
The question is - is this going to work? i.e. if I set B6 to high (3.3V), it will mean it is closed, right?
2. Use Miero's script for setting basic DAC registers.
The question is - how to connect isolated i2c to Dual Mono BIII's? Just by paralleling the wires?
3. Set IIR Bandwidth to 70K via switches on BIII board, no matter what is playing 🙂
Please advise.
Thanks,
Fedor
Option 1 is the least practical - because you will break isolation.
Option 2 is excellent - yes you can simply daisy chain the I2C - just remove the stock controller.
Option 3 is also excellent - the DAC actually sounds very good in this configuration.
DSD is just fine with the standard IIR - I am not sure why you have the impression you need to change anything 🙂 The lower BW has a positive effect on PCM - but not really a negative effect on DSD.
Still if you like DSD better with the higher IIR - then I would recommend approach 2 or 3. 🙂
Cheers!
Russ
Option 2 is excellent - yes you can simply daisy chain the I2C - just remove the stock controller.
Option 3 is also excellent - the DAC actually sounds very good in this configuration.
DSD is just fine with the standard IIR - I am not sure why you have the impression you need to change anything 🙂 The lower BW has a positive effect on PCM - but not really a negative effect on DSD.
Still if you like DSD better with the higher IIR - then I would recommend approach 2 or 3. 🙂
Cheers!
Russ
Oh, sorry, one more thing - you say that connecting flag pins to BIII breaks the isolation. But then connecting flag pin to Otto switch pin (which in turn gets connected to BIII's ground) breaks isolation too?
Indeed - but you could insert a simple isolator between if you like - Or use an I2C port expander and the isolated I2C bus.
I wonder how folks handle BBB shutdown function when BBB installed in the enclosure. Can this be controlled by a switch somehow?
There are two headers J_RST(resets the BBB when momentarily closed) and J_P_SW(powers down the BBB when momentarily closed) for that.
Cheers!
Russ
Wow, Thanks, Russ! I thought I had to have a pencil at hand to push that button on BBB forever. 🙂
Russ:
There are 3 jumpers on the Hermes:
J1 - to charging battery
J2 - to use the Cronus 3.3V to power isolator I2C
and what is it:
J3 - ?
There are 3 jumpers on the Hermes:
J1 - to charging battery
J2 - to use the Cronus 3.3V to power isolator I2C
and what is it:
J3 - ?
Russ, if I understood correctly, you suggest to use isolated i2c header (if it is not used to control BIII), to set switch to high or low by controlling it from Botic somehow?
Also, by simple isolator, you mean something like this? ADUM1201 | datasheet and product info Dual-Channel Digital Isolator (1/1 Channel Directionality) | Analog Devices
J3 to connect the I2C isolated GND to clean GND (from cronus) this is not typically necessary if I2C is being used for your DAC - because you DAC is already connected to Cronus GND. So it is there for special cases.
What I mean is an I2C controlled port expander so to output mode. Like the port expander that is already on the B3 (but is used for input)
http://www.cosmo-ic.com/object/products/k1010.pdf
Or something as simple as this - mounted on the prototyping area and supplied with the clean supply on the clean side.
That is what the prototyping area is for. Special cases. 🙂
I have BIII in second case and connect via teleporter to Cronus.
To connect I2C I think I must short J2 and J3 and connect I2C from Hermes to BIII only via (GND,SDA,SCL).
Is it true?
That should work just fine. You need only connect J3 if there is no existing GND connection between the cronus and the BIII - but it should not hurt regardless.
Cheers!
Russ
Thanks, that's definitely better.
So with this approach I can use other flags to switch IIR bandwidth on BIII. I know you've said that it's not necessary, but I'd like to have this option anyway 🙂
Is it ok to set B6 and B7 pins on BIII to high or low to do the switch? I'm just making sure so I won't fry anything 🙂
And yes, prototyping area was a great idea, indeed.
Hi guys, what could I be doing wrong here?
I have my j1 jumpered and my battery plugged into the ext bat header. I had a 5v 1a power supply going to the barrel connector but it seems that the bbb was basically running only on battery power and when this dipped below 3.1v or so, it turned off. So I assumed my supply was not man enough and doubled up my 5v supply to 2a, but I'm still getting the exact same behaviour? It won't run at all with the battery unplugged from the header.
Yet I have been temporarily running it off a 1a phone charger into the USB power port with no issues (other than strangely, the leds on the hermes not being lit ever)
If I remove the hermes, it boots fine using my 5v barrel supply.
Is my 5v supply duff or am I missing something in my hermes setup?
Thanks,
James
I have my j1 jumpered and my battery plugged into the ext bat header. I had a 5v 1a power supply going to the barrel connector but it seems that the bbb was basically running only on battery power and when this dipped below 3.1v or so, it turned off. So I assumed my supply was not man enough and doubled up my 5v supply to 2a, but I'm still getting the exact same behaviour? It won't run at all with the battery unplugged from the header.
Yet I have been temporarily running it off a 1a phone charger into the USB power port with no issues (other than strangely, the leds on the hermes not being lit ever)
If I remove the hermes, it boots fine using my 5v barrel supply.
Is my 5v supply duff or am I missing something in my hermes setup?
Thanks,
James