Performance

Overview

It is critical that you can generate all the needed samples within the indicated sample rate! The speed is also driving the polyphonic performance of the instrument. If it takes longer to generate all samples then to play them, the instrument can not be used for life playing!

Measurements

I was measuring the speed of the different instruments on an different microcontrollers.

Time for 10 sec music at 44100 samples per second

Instrument	ESP32	RP2040	STM32 Backpill	Unit
BeeThree	3.563	25.805	7.343	sec
BlowHole	2.117	23.245	4.706	sec
Bowed	17.748	32.134	47.184	sec
Clarinet	1.588	12.922	3.296	sec
Drummer	0.114	0.507	na	sec
Flute	1.969	16.884	4.462	sec
Rhodey	4.178	32.288	8.76	sec
TubeBell	4.348	32.798	8.902	sec
Mandolin	1.102	13.205	2.489	sec
ModalBar	0.677	17.875	1.895	sec
Moog	1.17	14.71	3.035	sec
Plucked	0.235	3.783	0.608	sec
Saxofony	1.73	21.633	3.732	sec
Shakers	0.111	0.424	0.347	sec
Sitar	1.206	7.615	2.833	sec
StifKarp	0.683	18.049	1.983	sec
TubeBell	4.349	32.798	8.902	sec
Wurley	4.154	32.01	8.683	sec
BlowBotl	2.782	17.962	5.915	sec
Brass	1.637	15.38	3.617	sec
FMVoices	9.865	45.061	18.113	sec
PercFlut	11.777	47.937	21.327	sec
HevyMetl	11.351	46.699	20.48	sec
Recorder	53.974	119.6	84.332	sec
Resonate	0.972	5.681	1.885	sec
Simple	2	12.641	4.573	sec
Whistle	37.664	85.35	82.983	sec

Conclusions

Many instruments can be used on the ESP32, put we are limited in the number of polyphonic voices. The RP2040 is too slow for the selected sample rate!

I was disappointed from the performance of the STM32 Blackpill which boasts of having a floating point unit!

Arduino Sketch

The Instrument Performance Sketch can be found on github.