Balanced Volume Controller / Line Stage

[alexcp]

Thank you for ordering! Give me a day to check what I can include with it as a controller.

As for a limited menu idea - thank you. I will think about a practical way to make it work.

[alexcp]

Here is a one minute video showing the MUSES board and the controller in action.

The display is a 4-digit alphanumeric LED display from Spark X, based on the HT16K33 controller. The volume level is displayed in percent, 0 to 100. The remote is an old (white) Apple remote; the newer aluminium one also works. Pairing and unpairing of the remote is supported.

[astromo]

Blue display in keeping with First Watt / Pass Labs - I like it.

Does the job. Looks and sounds good to me.

[astromo]

As a follow on, any idea of the product longevity of the SPX-16426?

There's a comment on the linked page Qwiic Alphanumeric Display, Blue, SPX-16426 reads:

We do not plan to regularly produce SparkX products so get them while they’re hot!

Obsolescence is a moving target but is Sparkfun just trying to coax uptake or are they signalling something else? The listing at Mouser 474-SPX-16426 is telling me it's a new product, so hopefully that means it has a while to go before it gets the axe. Probably just mixed messages.

Even so, it looks like a good option. Sparkfun's documentation helps those slow on the uptake like me.


EDIT: Based on what I'm seeing here, my guess is that this piece of kit will hang around for a while.

[alexcp]

Mouser in the US has only one in stock. Although the hardware design files are available from SparkFun, and the board can easily be replicated, the specific LED display they used is nowhere to be found. I guess I will need to switch to a display with longer term availability. Shouldn’t be too difficult.

[alexcp]

The controller board is 1.1x1.1in and carries six 0.1in pitch headers:

• Eight pin in two rows for the volume control board
• Four pin for the display
• Three pin to connect an IR receiver for remote control
• Two pin for an LED (not used by the current firmware)
• Six pin, single row for a serial port
• Six pin, double row In-System-Programming (ISP) port

The last two connectors are mainly intended for development and are not used by the current firmware, so I may remove them from the production version.

All connectors except LED carry power, so any one of them can be used to power the board, and the remaining ones - to provide power to other devices. Normally, the power is provided by the volume controller board, which carries a 5-volt regulator. In turn, the controller provides power to the IR receiver and display. Other arrangements may be possible. The controller board needs between 2.7 to 5.5 volts. The display from SparkX works with both 3.3 and 5 volts.

The attached pictures show the size of the board and connector placement.

[astromo]

Nice work.

What are the units of measure for the dimensions shown?

[alexcp]

Thank you! The dimensions are in 1/1000 in.