Search found 43 matches

by Davidelvig
Wed 2022-03-30 21:45
Forum: DSP and Audio Software
Topic: Low pass filter on top of MIDI synth
Replies: 7
Views: 428

Re: Low pass filter on top of MIDI synth

Thanks, Pasi! This looks good, though I'm going to try the Bass Enhancer and Treble Control feature first. I have it mostly fleshed out. I have one question about Treble Control in the documentation section 9.6.3 SCI_BASS (RW) Name/Bits/Description ST_AMPLITUDE/15:12/Treble Control in 1.5 dB steps (...
by Davidelvig
Tue 2022-03-29 22:04
Forum: DSP and Audio Software
Topic: Low pass filter on top of MIDI synth
Replies: 7
Views: 428

Re: Low pass filter on top of MIDI synth

Thanks!
This sounds promising.
I would welcome the recipe to implement this.
by Davidelvig
Tue 2022-03-29 3:31
Forum: DSP and Audio Software
Topic: Low pass filter on top of MIDI synth
Replies: 7
Views: 428

Re: Low pass filter on top of MIDI synth

Interesting. I had thought about using base boost and treble control as kind of a rough sweeping filter. I really, I could get something that would make a sweep of a low-pass cutoff filter frequency in 128 steps (from 20Hz to 20kHz). It's a cool effect. Which approach would get me closer to the abov...
by Davidelvig
Wed 2022-03-23 20:53
Forum: DSP and Audio Software
Topic: Low pass filter on top of MIDI synth
Replies: 7
Views: 428

Low pass filter on top of MIDI synth

I’m using the VS1053 for an internal synth in a MIDI Wind Controller. I’m sending MIDI messages through SPI, and have a headphone jack connected to the VS1053 for output. I’d like to continue using the MIDI synth, but add a low-pass filter to the signal path (after the synth) where the low pass cuto...
by Davidelvig
Thu 2021-03-04 23:48
Forum: Stand-Alone Applications
Topic: Distortion with some VS1053 instruments playing high notes
Replies: 1
Views: 1012

Distortion with some VS1053 instruments playing high notes

I have a VS1053 chip on my board, playing well in all respect except: - on certain instruments (trumpet, MIDI Program 56) and others to some degree, I get distortion on higher notes. I'm sending MIDI through SPI to the chip. No other audio or data inputs. Output is through a headphone, or in this ca...
by Davidelvig
Wed 2020-07-29 18:44
Forum: Slave Decoder Applications
Topic: Minimal MIDI decoder
Replies: 37
Views: 20668

Re: Minimal MIDI decoder

Brilliant! Implemented in 10 minutes. Thanks @pasi! For those interested, here's a snippet. I added the if (MIDIThroughSPI) clauses to two MIDI message sending methods. void dbMIDISynth::writeTwo(unsigned char a, unsigned char b) { if (MIDIThroughSPI) { uint8_t bytes[4] = {0, a, 0, b}; if (!WriteSDI...
by Davidelvig
Wed 2020-07-29 0:29
Forum: Slave Decoder Applications
Topic: Minimal MIDI decoder
Replies: 37
Views: 20668

Re: Minimal MIDI decoder

Regarding MIDI through SDI while in RT MIDI mode: I have the VS1053b on my own board, running well with RT MIDI initialized at startup. Serial MIDI streams through the Rx pin work well. SCI commands work perfectly (tested for SCI_VOL, SCI_BASS and SCI_MODE for EarSpeaker). I'd like to try sending th...
by Davidelvig
Mon 2020-06-08 18:54
Forum: Microcontroller Software
Topic: VS1053 over voltage risk
Replies: 6
Views: 2727

Re: VS1053 over voltage risk

All appears when when the crystal is oscillating, and the SPI query you suggested returns the correct result. I had a bad connection at the 1Mohm resistor. Now the crystal starts oscillating on power up. I'm still tracking down a failure to oscillate when I perform a reset on my main processor chip,...
by Davidelvig
Mon 2020-06-08 15:19
Forum: Microcontroller Software
Topic: VS1053 over voltage risk
Replies: 6
Views: 2727

Re: VS1053 over voltage risk

I've just found that the 12.288 crystal is not oscillating when the above symptoms exist. When the crystal oscillates, I get proper pin values.
I'll let you know what I find out.
by Davidelvig
Mon 2020-06-08 0:09
Forum: Microcontroller Software
Topic: VS1053 over voltage risk
Replies: 6
Views: 2727

Re: VS1053 over voltage risk

OK, I did have a wiring problem with XRESET, which is now addressed. After that fix (and resetting with XRESET LO for 100ms then left at HI), I get: - RCAP, LEFT, RIGHT and GBUF all are at 1.2v ... but DREQ stays low I have the following set up with resistors at startup. - GPIO0 pulled LO to 0v; and...