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More sample rates on NRF52
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- PDM microphone on NRF52 now supports 16khz, 20khz, 31.25khz and 41.672khz sample rates
- Remove duplicate functions
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@TMRh20
TMRh20 committed Apr 4, 2024
1 parent a2a9a3d commit e9b344d
Showing 1 changed file with 60 additions and 52 deletions.
112 changes: 60 additions & 52 deletions src/NRF52840/AutoAnalogAudio.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -22,9 +22,11 @@

#include "../AutoAnalogAudio.h"
#include <hal/nrf_pdm.h>
#include <hal/nrf_i2s.h>

//#define USE_I2s
#if defined USE_I2s
#include <hal/nrf_i2s.h>
#endif

#if !defined __MBED__
#define myPDM NRF_PDM0
Expand All @@ -42,18 +44,30 @@
#ifndef NRF_PDM_FREQ_1280K
#define NRF_PDM_FREQ_1280K (nrf_pdm_freq_t)(0x0A000000UL) ///< PDM_CLK= 1.280 MHz (32 MHz / 25) => Fs= 20000 Hz
#endif
#define DEFAULT_PDM_GAIN 40
#ifndef NRF_PDM_FREQ_2667K
#define NRF_PDM_FREQ_2667K (nrf_pdm_freq_t)(0x15000000UL)
#endif
#ifndef NRF_PDM_FREQ_2000K
#define NRF_PDM_FREQ_2000K (nrf_pdm_freq_t)(0x10000000UL)
#endif

/******************* USER DEFINES - Configure pins etc here *****************/
#define DEFAULT_PDM_GAIN 40

/* I2s config */
#define PIN_MCK 15//(13)
#define PIN_SCK 13//(14)
#define PIN_LRCK 14//(15)
#define PIN_SDOUT (5)
#define DEFAULT_PWM_PIN 5
#define PIN_SDOUT (5) // GPIO Pin numbers

#ifndef PIN_PDM_DIN
#define PIN_PDM_DIN 1
#define PIN_PDM_CLK 2
#define PIN_PDM_PWR 3
/* PWM Config */
#define DEFAULT_PWM_PIN 5 //GPIO Pin number
//#define DEFAULT_PWM_PIN2 4

#ifndef PIN_PDM_DIN // Arduino pin numbers
#define PIN_PDM_DIN 35
#define PIN_PDM_CLK 36
#define PIN_PDM_PWR -1
#endif

/****************************************************************************/
Expand Down Expand Up @@ -94,6 +108,7 @@ void AutoAnalog::begin(bool enADC, bool enDAC){
if(enADC){

set_callback(adcCallback);

dinPin = PIN_PDM_DIN;
clkPin = PIN_PDM_CLK;
pwrPin = PIN_PDM_PWR;
Expand Down Expand Up @@ -177,11 +192,6 @@ void AutoAnalog::begin(bool enADC, bool enDAC){
//Set default 16khz sample rate
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio80 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
nrf_pdm_clock_set(myPDM,NRF_PDM_FREQ_1280K);
//nrf_pdm_clock_set(NRF_PDM_FREQ_1032K);
//nrf_pdm_clock_set(NRF_PDM_FREQ_1067K);
// NRF_PDM_FREQ_1000K = PDM_PDMCLKCTRL_FREQ_1000K, ///< PDM_CLK = 1.000 MHz.
// NRF_PDM_FREQ_1032K = PDM_PDMCLKCTRL_FREQ_Default, ///< PDM_CLK = 1.032 MHz.
// NRF_PDM_FREQ_1067K = PDM_PDMCLKCTRL_FREQ_1067K ///< PDM_CLK = 1.067 MHz.

//Set default channel mono
nrf_pdm_mode_set(myPDM,NRF_PDM_MODE_MONO, NRF_PDM_EDGE_LEFTFALLING);
Expand Down Expand Up @@ -280,14 +290,15 @@ void AutoAnalog::begin(bool enADC, bool enDAC){
// Start transmitting I2S data
NRF_I2S->TASKS_START = 1;
#else
pinMode(DEFAULT_PWM_PIN,OUTPUT);
digitalWrite(DEFAULT_PWM_PIN,LOW);


NRF_PWM0->PSEL.OUT[0] = (DEFAULT_PWM_PIN << PWM_PSEL_OUT_PIN_Pos) | (PWM_PSEL_OUT_CONNECT_Connected << PWM_PSEL_OUT_CONNECT_Pos);
#if defined DEFAULT_PWM_PIN2
NRF_PWM0->PSEL.OUT[1] = (DEFAULT_PWM_PIN2 << PWM_PSEL_OUT_PIN_Pos) | (PWM_PSEL_OUT_CONNECT_Connected << PWM_PSEL_OUT_CONNECT_Pos);
#endif
NRF_PWM0->ENABLE = (PWM_ENABLE_ENABLE_Enabled << PWM_ENABLE_ENABLE_Pos);
NRF_PWM0->MODE = (PWM_MODE_UPDOWN_Up << PWM_MODE_UPDOWN_Pos);
NRF_PWM0->PRESCALER = (PWM_PRESCALER_PRESCALER_DIV_1 << PWM_PRESCALER_PRESCALER_Pos);
NRF_PWM0->COUNTERTOP = (((uint16_t)((16000000/DEFAULT_FREQUENCY) + 5)) << PWM_COUNTERTOP_COUNTERTOP_Pos); //1 msec
NRF_PWM0->COUNTERTOP = (((uint16_t)((16000000/DEFAULT_FREQUENCY))) << PWM_COUNTERTOP_COUNTERTOP_Pos); //1 msec
NRF_PWM0->LOOP = (0 << PWM_LOOP_CNT_Pos);
NRF_PWM0->DECODER = (PWM_DECODER_LOAD_Common << PWM_DECODER_LOAD_Pos) | (PWM_DECODER_MODE_RefreshCount << PWM_DECODER_MODE_Pos);
NRF_PWM0->SEQ[0].PTR = ((uint32_t)(&dacBuf0[0]) << PWM_SEQ_PTR_PTR_Pos);
Expand All @@ -313,14 +324,27 @@ void AutoAnalog::setSampleRate(uint32_t sampRate, bool stereo){
uint32_t timer = millis();
while(NRF_PWM0->EVENTS_STOPPED == 0){ if(millis() - timer > 1000){break;} }

NRF_PWM0->COUNTERTOP = (((uint16_t)((16000000/sampRate) + 5)) << PWM_COUNTERTOP_COUNTERTOP_Pos);
NRF_PWM0->COUNTERTOP = (((uint16_t)((16000000/sampRate))) << PWM_COUNTERTOP_COUNTERTOP_Pos);
NRF_PWM0->TASKS_SEQSTART[0] = 1;

if(sampRate == 20000){
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio64 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
}else{
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio80 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
}


if(sampRate <= 16000){
//Set default 16khz sample rate
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio80 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
nrf_pdm_clock_set(myPDM,NRF_PDM_FREQ_1280K);
}else
if(sampRate <= 20000){
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio64 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
nrf_pdm_clock_set(myPDM,NRF_PDM_FREQ_1280K);
}else
if(sampRate <= 31250){
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio64 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
nrf_pdm_clock_set(myPDM, NRF_PDM_FREQ_2000K); //2667 / 64 = 33.337khz, /80 = 41.667
}else
if(sampRate <= 41672){
NRF_PDM->RATIO = ((PDM_RATIO_RATIO_Ratio64 << PDM_RATIO_RATIO_Pos) & PDM_RATIO_RATIO_Msk);
nrf_pdm_clock_set(myPDM, NRF_PDM_FREQ_2667K); //2667 / 64 = 33.337khz, /80 = 41.667
}

}

Expand Down Expand Up @@ -355,11 +379,9 @@ void AutoAnalog::disableAdcChannel(uint8_t pinAx){
/****************************************************************************/

void AutoAnalog::getADC(uint32_t samples){
// #if defined __MBED__
while(!adcReady){__WFE();};
aSize = samples;
adcReady = false;
// #endif
}

/****************************************************************************/
Expand Down Expand Up @@ -534,19 +556,8 @@ if (nrf_pdm_event_check(NRF_PDM_EVENT_STARTED)) {
}
}

void AutoAnalog::set_callback(void(*function)(uint16_t *buf, uint32_t buf_len)){
_onReceive = function;
}

void AutoAnalog::adcCallback(uint16_t *buf, uint32_t buf_len){

for(uint32_t i=0; i < buf_len; i++){
adcBuffer16[i] = buf[i];
}

adcReady = true;
}
#elif !defined MBED

extern "C" {
__attribute__((__used__)) void PDM_IRQHandler(void)
{
Expand Down Expand Up @@ -583,11 +594,21 @@ if (nrf_pdm_event_check(myPDM,NRF_PDM_EVENT_STARTED)) {
}
}

extern "C" {
__attribute__((__used__)) void PWM0_IRQHandler(void){

//AutoAnalog::sampleCounter++;

}


}
#endif // defined __MBED__

void AutoAnalog::set_callback(void(*function)(uint16_t *buf, uint32_t buf_len)){
_onReceive = function;
}


void AutoAnalog::adcCallback(uint16_t *buf, uint32_t buf_len){

for(uint32_t i=0; i < buf_len; i++){
Expand All @@ -596,18 +617,5 @@ void AutoAnalog::adcCallback(uint16_t *buf, uint32_t buf_len){
adcReady = true;
}

extern "C" {
__attribute__((__used__)) void PWM0_IRQHandler(void){

//AutoAnalog::sampleCounter++;

}


}




#endif
#endif //#if defined (ARDUINO_ARCH_SAM)

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