PeppyMeter: can I run it stand-alone as VU-meter display only, synched with my wireless speakers?

[KolfMAKER]

So on the software side:

1. Use the disk image (based on Raspberry Pi OS (32-bit) Lite 05/07/2021 [Buster])which has only PeppyMeter + peppyalsa plugin installed.
2. Adjust the resolution to the used display.

And connection wise between Up2Stream board and Raspberry Pi it should look like this, correct?

 

[phofman]

@KolfMAKER : your connection traces confuse pin ids with GPIO ids. E.g. note that your IIS_DATA would be connected to GND on the RPi.

The correct traces are e.g. https://github.com/makerportal/rpi_i2s or https://www.pschatzmann.ch/home/2020/03/25/music-from-a-raspberry-pi-over-i2s/ You need to connect data to DIN (GPIO 20 = pin 38).

Also you need GND and VCC_3V3.

 

[KolfMAKER]

Ah, get what you mean @phofman

So from Up2Stream to Pi, connections should be as follows:

• BCLK > Pin 12 / GPIO18 PCM_CLK
• LRCLK > Pin 35 / GPIO19 PCM_FS
• IIS_DATA > Pin 38 / GPIO 20 PCM_DIN
• GND > any of the eight GND pins on the Pi? (6, 9, 14, 20, 25, 30, 34, 39)
• VCC_3V3 > any of the two 3V3 pins (1, 17)

Checks:

• Is this what you meant?
• And correct to connect with 3 pins between Up2Stream and Pi?

 

[phofman]

Seems correct. 5 pins in total (including GND and power).

 

[KolfMAKER]

Thnx @phofman

I guess the GND and 3V3 connections, are they to power the Up2Stream board via the Pi?
(Then I should check if that power is enough for the Up2Stream)

 

[phofman]

The GND is return path for the signals. Every signal needs two paths - signal and return, the signal current must have a way to return to its source, otherwise it cannot flow.

+3V3 is needed if your board has no other power supply.

 

[KolfMAKER]

Ah right, that makes sense of course.

My board needs 5V and between 800mA <>1A.
My VU-meter LCD screen needs 5V and 3A.

Would it be possible to power my board and the touchscreen through the Pi, if I use a proper power supply to the Pi?

 

[phofman]

If the board requires 5V, then those 3.3V pins are outputs from some internal 3.3V PSU and should not be connected to RPi.

You can e.g. power RPi and the board from the same PSU, feeding 5V to the RPi GPIO pins and not through the USB-C.

 

[KolfMAKER]

Thnx @phofman.

Do you mean to use one PSU to the Raspberry Pi, and take 5v from the GPIO pins to my board?

 

[phofman]

One PSU, powering both RPi through the GPIO pins and your board.