Looking at the ALLO docs a bit more I have the impression that the J8 connector on the relay board has a completely different pinout than what's available from the RPI pin header. If I am right (which I am hopefully not), the Allo relay board will not work off the RPI pin header. If so, I'd have to fiddle around with jumper wires... is this really how it works? A bit more documentation about using the relay board off the standard RPI pin header without an Allo DAC would be in order since the first post says that this board can be used "stand alone".
You seem to be right. I'd always assumed that J8 would be compatible with the RPi's GPIO header but that does not appear to be the case.
Ioan, can you confirm that?
In any case, it appears that board only needs +5V, SCK, SDA, GPIOB15 and GND to function. They should not be hard to "steal" from the RPi & DAC+ Pro.
Ioan, can you confirm that?
In any case, it appears that board only needs +5V, SCK, SDA, GPIOB15 and GND to function. They should not be hard to "steal" from the RPi & DAC+ Pro.
Ok, I installed a pinheader to the HifiBerry and hooked up the Relay Attenuator board to +5V, SCK, SDA, GPIOB15 and GND. I installed and activated the Volumio plugin. I also disabled the software volume control in Volumio.
The relays don't respond to the Volumio volume control. I can hear the relays clicking when I connect or disconnect the 5V power, but that's about it.
Any thoughts how to debug this?
Here's a photo of the setup. Would be cool if someone has an idea of what might be wrong.
Attachments
I need a programmable attenuator without a DAC; will Volumio control the Allo attenuator with nothing else connected to the Pi? That is, can I use the Volumio web interface to control the Allo attenuator alone? Or will Volumio not work properly because there is no DAC connected?
And yes, I would like another relay so I could have half-dB steps, but the current Allo attenuator doesn't offer that. Maybe a future version?
And yes, I would like another relay so I could have half-dB steps, but the current Allo attenuator doesn't offer that. Maybe a future version?
Thank you mbrennwa; I have PM'ed you.
Looking at the Volumio documentation, the graphical volume control goes from 0 to 100, but the Allo attenuator goes from 0 to 64. Has anyone tweaked the Volumio source to get a one-to-one mapping from UI to attenuator dB? I will use this for recording, so if my current level peaks at -15.6 dB, then I want to add exactly 15 dB so that my recording peaks at -0.6 dB. That means I need a one-to-one mapping from UI to attenuator level.
Looking at the Volumio documentation, the graphical volume control goes from 0 to 100, but the Allo attenuator goes from 0 to 64. Has anyone tweaked the Volumio source to get a one-to-one mapping from UI to attenuator dB? I will use this for recording, so if my current level peaks at -15.6 dB, then I want to add exactly 15 dB so that my recording peaks at -0.6 dB. That means I need a one-to-one mapping from UI to attenuator level.
using the attenuator with Buster
My apologies for re-opening an old thread. I have one of these attenuators and am very happy with its performance. However I am not using Volumio and so the only way I have of controlling volume is through direct access over the i2c bus. I would like to tie the attenuator to the volume in MPD, but it seems to me that MPD will seek to change the volume on the DAC. Does anybody have experience of using this device through ALSA / MPD??
My apologies for re-opening an old thread. I have one of these attenuators and am very happy with its performance. However I am not using Volumio and so the only way I have of controlling volume is through direct access over the i2c bus. I would like to tie the attenuator to the volume in MPD, but it seems to me that MPD will seek to change the volume on the DAC. Does anybody have experience of using this device through ALSA / MPD??
What software are you using to control the attenuator? I have been completely unable to get Volumio to control it - the GUI acts as though it is controlling it, but the volume never changes. Submitting logs and posting a message to the Volumio forum doesn't seem to do very much - two months with no reply. This is with Volumio 2.587 and version 1.3 of the relay attenuator plugin.
I believe had to install a plugin in Volumio to make the relay attenuator work. Installing plugins can be trouble in Volumio if you changed the password of the default Volumio user.
I have installed the plugin, and I haven't changed the Volumio password, and I have done it multiple, multiple times, with both Volumio 2.587 and 2.632, with two different RPi 3 B+, and with two different memory cards. Every time the Volumio UI comes up in my browser and I can change the displayed volume, and the actual volume changes not at all.
Regardless of the volume setting on the UI, the resistance between input and output is 12K ohms, and the resistance between input and ground is zero ohms. So, regardless of the volume setting and regardless of the status of the Mute button, the relay attenuator is muting the input. As far as I can tell the relay attenuator is a complete waste of money. It doesn't work, and there is no support from the manufacturer.
Regardless of the volume setting on the UI, the resistance between input and output is 12K ohms, and the resistance between input and ground is zero ohms. So, regardless of the volume setting and regardless of the status of the Mute button, the relay attenuator is muting the input. As far as I can tell the relay attenuator is a complete waste of money. It doesn't work, and there is no support from the manufacturer.
I have figured out the problem - despite their sales literature, the relay attenuator won't work in this configuration. Their website says "To use it with any analog source: simply plug the analog output you want to control in the inputs of Allo Relay Attenuator and plug its output to your amplifier. This is extremely useful if your USB DAC does not have hardware volume control and you use it with your Raspberry PI. PLEASE NOTE: TO USE THE ALLO RELAY ATTENUATOR DIRECTLY ON THE RASPBERRY PI you need GPIO spacers, since the Allo Relay Volume Attenuator is not HAT compliant." (Capitals are mine for emphasis)
This strongly implies that you can actually _use_ the Allo RA directly on a Raspberry PI, but in fact you can't - the sodding idiots changed the GPIO pinout! That is, their connector on the Allo RA will physically mount on the PI and plug into a GPIO extender, but it puts things like power and ground in completely different places! You can see this if you look at the J8 pinout on page 4 of the RA Technical Manual.
And their support is anywhere from bad to nonexistent. I have posted 12 times on the Allo support forum and submitted logs three times, all the way from December 2018 until last week, and have received exactly ZERO replies from Allo staff. Another user offered suggestions on GPIO spacers.
So, I have a useless relay attenuator. My recommendation is to not purchase any Allo product.
This strongly implies that you can actually _use_ the Allo RA directly on a Raspberry PI, but in fact you can't - the sodding idiots changed the GPIO pinout! That is, their connector on the Allo RA will physically mount on the PI and plug into a GPIO extender, but it puts things like power and ground in completely different places! You can see this if you look at the J8 pinout on page 4 of the RA Technical Manual.
And their support is anywhere from bad to nonexistent. I have posted 12 times on the Allo support forum and submitted logs three times, all the way from December 2018 until last week, and have received exactly ZERO replies from Allo staff. Another user offered suggestions on GPIO spacers.
So, I have a useless relay attenuator. My recommendation is to not purchase any Allo product.
Ouch! Your experience with Allo was even worse than mine.
You could mess around with jumper wires to connect the RPi to the relay board in order to deal with the different pinouts. See my earlier post here.
However, you'd still have to live with the silly GND arrangement of the Allo relay board. The PCB connects the GNDs that should not be connected (either left / right channel GNDs, or audio / digital GNDs, or both; I don't remember exactly). UPDATE: see here.
You could mess around with jumper wires to connect the RPi to the relay board in order to deal with the different pinouts. See my earlier post here.
However, you'd still have to live with the silly GND arrangement of the Allo relay board. The PCB connects the GNDs that should not be connected (either left / right channel GNDs, or audio / digital GNDs, or both; I don't remember exactly). UPDATE: see here.
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I have already used jumper wires to connect J8 to the RPi GPIO header; the Volumio software now recognizes that the RA is there, but the RA never changes the volume. I know that the software has seen the RA because it now limits the control range to 0-63 rather than 0-100 - but it doesn't work. I am quite through with Allo.