[How to do instruction] 128x64 OLED with Song Status and Spectrum Display on Raspberry Pi

[jit-010101]

Given that there's a hint in Moode 9 in regards to ALSA Loopback not being supported with CamillaDSP has anyone gotten it to work via configuration changes like mentioned in the CamillaDSP repositories? Say getting CamillaDSP to work with Alsa Loopback for mpd_oled ...

[Tim Curtis]

I haven't tested but give this a try

Code:

/var/www/snd-config.php
//$_alsa_loopback_disable = $_SESSION['camilladsp'] != 'off' ? 'disabled' : '';
$_alsa_loopback_disable = '';

/etc/alsa/conf.d/_sndaloop.conf
slaves {
//a { channels 2 pcm "hw:3,0" }
a { channels 2 pcm "camilladsp" }
b { channels 2 pcm "hw:Loopback,0" }

[bagelwoof]

Is SPI that much faster? Or otherwise better?

[adrii]

Hi bagelwoof

I don't know about newer Pi's but I think the maximum supported speed for I2C is 400 kb/s, which is not quite enough for a smooth display. However, the value can be set to 800 kb/s, and this works for me. SPI speeds can achieve higher transfer rates.

You may have other I2C or SPI devices connected, and prefer a protocol based on compatibility with these devices.

You may have certain pins in use, or unavailable due to a HAT, and so make a choice based on that.

I2C is convenient in only needing 4 wires.

Adrian.

[bagelwoof]

Hi bagelwoof

I don't know about newer Pi's but I think the maximum supported speed for I2C is 400 kb/s, which is not quite enough for a smooth display. However, the value can be set to 800 kb/s, and this works for me. SPI speeds can achieve higher transfer rates.

Thanks for the info. I had no idea that we could modify the I2C bus speed.

There's some discussion that the Pi5 might be supported up to 1Mhz? 
How to configure I2C on Pi5 to run with 1MHz - Fast Mode Plus

Apparently, the default is still 100khz. ...ouch...

It looks like we can still use mpd_oled with I2C on a Pi5. Is that correct?

It seems like this problem should also be present on the Pi4 if we use a Moode 9 image, but that's not what I'm picking up from reading this thread. Can we drive an SPI display with Moode 9 on a Pi4?

[adrii]

Hi bagelwoof

SPI screens cannot be used with mpd_oled on a Pi5. I'm not sure if I have received confirmation that I2C screens work, but it is possible that they will.

For Moode 9 on a Pi4 you have to build mpd_oled fron source. I have tested an I2C and an SPI screen and both were working.

Adrian.

[bagelwoof]

Hi bagelwoof

SPI screens cannot be used with mpd_oled on a Pi5. I'm not sure if I have received confirmation that I2C screens work, but it is possible that they will.

Thanks, Adrian 



I have a Moode setup on a Pi 5 with one of these on top: https://52pi.com/collections/hat-addons/...2pi-nvdigi, and have an I2S display on order. I'll give it a go sometime in the next week or so; and I'll post back here when I find out the hard way.

I'm refreshing a bunch of older Pi4 things with Pi5s and will be setting up a couple more players, so if the display doesn't work on the 5, there are a few 4s it can go to...