Vumeter in bela

qhr33k

Hi everyone, I would like to build a matrix mixer with a bela mini with 8 inputs and outputs. Do you think it is possible to have a decent vumetering performance thru a screen compatible with bela? I will need at least 8 bars of vumeter. I am proficient in puredata that has a builtin vumeter object, is that a good way to go? How would you do that? The mixer should include very simple reverb and delay as internal send, and extensive routing options. Thanks in advance for your help.

giuliomoro

If all you need is a avumeter you could use some neopixels to do just that using this project

https://github.com/giuliomoro/O2L/tree/pixelbone

qhr33k

Ave Giulio, thanks for your answer. I need a little more than vumeter , and the led way is really tempting, but I prefer a screen at the moment. I never used OSC, but it can be what I need. Do you have any experience of vumeter in OSC? Is OSC fast enough to show 8 vumeters on a device connected thru WiFi to bela mini or a screen on the beaglebone itself? My actual setup is a raspberry pi with a multichannel usb sound card running a PD patch and that is my mixer. I will test OSC in that context. Thanks again for your help.

giuliomoro

You could use an OLED display then. Monochrome ones can be accessed via OSC with O2O.

If you send three floats to the /parameter path these get displayed as bars of variable width which can work as vumeters. It can be modified and extended to display more.

OSC is compact enough that it won't become your bottleneck. Just make sure you send data slow enough (e.g.: 20 or 30 times per second) that the display can keep up.

qhr33k

Hi Giulio, I will go with mono led screen way. Any advice on screen model, size or any electronic limitation you can tell me? Thanks a lot for your help.

giuliomoro

In principle all the I2C displays listed here should work.

A handful that have successfully been tested in the past are listed here https://github.com/giuliomoro/O2O/blob/main/u8g2/U8g2LinuxI2C.h: SH1106, SSD1306, SSD1309

qhr33k

Ave Giulio, my mixer is progressing at lightspeed for my standard, the documentation is very useful and clear, I love it, congrats to the bela team. I am actually trying to hookup a blokas midipi to bela to add i2c midi capabilites. I am confused about the pins to use. I should have
3.3 v
Ground
SDA
SCL
but looks like the midipi is requesting two more pins
RESET and a sort of index control.
Any idea where should I connect those pins to my multichannel mini bela board?
Here is a link to the pins scheme of the midipi.
https://blokas.io/pimidi/docs/specs/
Thanks in advance for your help.

giuliomoro

Without reading much: I think you don't need the reset pin. You should monitor the data ready pin and when it toggles you should read three bytes over i2c.