Search found 308 matches

by ChrisMicro
Mon Nov 13, 2017 9:38 pm
Forum: Code snipplets
Topic: 4 channel polyphonic tone generator (blue pill)
Replies: 14
Views: 171

Re: 4 channel polyphonic tone generator (blue pill)

>But does it have only 1 output?

Yes, the signals are "analog" like waveforms and are added internally.

It is done here ( line 277 ).
by ChrisMicro
Sun Nov 12, 2017 4:56 pm
Forum: Code snipplets
Topic: 4 channel polyphonic tone generator (blue pill)
Replies: 14
Views: 171

Re: 4 channel polyphonic tone generator (blue pill)

Nice :D

Did you try this one.
It's a five channel synth ;-)
by ChrisMicro
Mon Nov 06, 2017 8:11 pm
Forum: STM Core
Topic: [Deprecated: old core]Introducing the new delivery for STM
Replies: 83
Views: 4591

Re: [Deprecated: old core]Introducing the new delivery for STM

I don't know because I used the timer only in the STM32GENERIC framework:

https://github.com/ChrisMicro/STM32GENE ... neWave.ino
by ChrisMicro
Tue Oct 31, 2017 6:55 am
Forum: Code snipplets
Topic: simple sound player: PWM audio output, with DMA, without timer interrupt
Replies: 29
Views: 395

Re: simple sound player: PWM audio output, with DMA, without timer interrupt

The reason to increase PWM frequency is to reduce distortions, see: http://www.openmusiclabs.com/learning/d ... dac.1.html, chapter 4.
This is really the best link I ever saw regarding this topic. Thanx .

Even the BluePill is mentioned. :D
by ChrisMicro
Mon Oct 30, 2017 5:57 pm
Forum: Code snipplets
Topic: simple sound player: PWM audio output, with DMA, without timer interrupt
Replies: 29
Views: 395

Re: simple sound player: PWM audio output, with DMA, without timer interrupt

I think the ear can't hear frequencies above 20 kHz. Therefore PWM frequencies above 20kHz are always enough. It might have other reasons when they use 140kHz in the PWM Audio-DACs. But what really matters: the resolution. The more bits, the better. There are various tricks in the mozzi library to i...
by ChrisMicro
Mon Oct 30, 2017 3:53 pm
Forum: Code snipplets
Topic: simple sound player: PWM audio output, with DMA, without timer interrupt
Replies: 29
Views: 395

Re: simple sound player: PWM audio output, with DMA, without timer interrupt

Anyway, the main point here is that my example does NOT use the timer ISR, just the DMA.
Yes, it is a good idea to use the DMA to avoid processing load.
If it would have been earlier available, I would have used your example ;-)
by ChrisMicro
Mon Oct 30, 2017 3:04 pm
Forum: Code snipplets
Topic: simple sound player: PWM audio output, with DMA, without timer interrupt
Replies: 29
Views: 395

Re: simple sound player: PWM audio output, with DMA, without timer interrupt

Some time ago I also made some sound player. for the STM32F103 in the GENERIC repo.
It has no DMA but the sound quality was OK.
It is only a sine wave but could easily be extended for playing a wav.
by ChrisMicro
Sun Oct 29, 2017 9:01 am
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 321
Views: 4645

Re: F405 & F411 versions of the BluePill

This one ? RobotDyn?
by ChrisMicro
Sun Oct 29, 2017 6:47 am
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 321
Views: 4645

Re: F405 & F411 versions of the BluePill

When is the board in production? I would like to have one ;-)
by ChrisMicro
Tue Oct 24, 2017 4:07 pm
Forum: Custom design boards
Topic: IceStamp FPGA in DIL28 and UPduino in DIL32
Replies: 16
Views: 407

Re: IceStamp FPGA Board in DIL28

Do they really cost only 7.99$ for
5.3K LUTs, 1Mb SPRAM, 120Kb DPRAM, 8 Multipliers ?

That is ways better than the 384 cells of the other board.
5.3K LUTs could even be sufficient for a small MC, I think.