Skip to content

Commit

Permalink
Fix analogWrite (esp8266#2299)
Browse files Browse the repository at this point in the history 
* Fix analogWrite

Move to NMI interrupt
Rework the whole ISR to take less and more constant cycles
Current defaults run 10bits/1KHz@160MHz and 9bit/1KHz@80MHz (soft
mapped)

* astyle and remove STORE_ATTR
  • Loading branch information
@me-no-dev @igrr
me-no-dev authored and igrr committed Jul 19, 2016
1 parent 9c36ff9 commit 6feecc5
Showing 1 changed file with 163 additions and 106 deletions.
269 changes: 163 additions & 106 deletions cores/esp8266/core_esp8266_wiring_pwm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,132 +24,189 @@
#include "eagle_soc.h"
#include "ets_sys.h"

#ifndef F_CPU
#define F_CPU 800000000L
#endif

struct pwm_isr_table {
uint8_t len;
uint16_t steps[17];
uint32_t masks[17];
};

struct pwm_isr_data {
struct pwm_isr_table tables[2];
uint8_t active;//0 or 1, which table is active in ISR
};

static struct pwm_isr_data _pwm_isr_data;

uint32_t pwm_mask = 0;
uint16_t pwm_values[17] = {0,};
uint32_t pwm_freq = 1000;
uint32_t pwm_range = PWMRANGE;

uint8_t pwm_steps_changed = 0;
uint32_t pwm_multiplier = 0;
uint16_t pwm_steps[17];
uint8_t pwm_steps_len = 0;
uint32_t pwm_steps_mask[17];

int pwm_sort_array(uint16_t a[], uint16_t al){
uint16_t i, j;
for (i = 1; i < al; i++) {
uint16_t tmp = a[i];
for (j = i; j >= 1 && tmp < a[j-1]; j--)
a[j] = a[j-1];
a[j] = tmp;
}
int bl = 1;
for(i = 1; i < al; i++){
if(a[i] != a[i-1]) a[bl++] = a[i];
}
return bl;

int pwm_sort_array(uint16_t a[], uint16_t al)
{
uint16_t i, j;
for (i = 1; i < al; i++) {
uint16_t tmp = a[i];
for (j = i; j >= 1 && tmp < a[j-1]; j--) {
a[j] = a[j-1];
}
a[j] = tmp;
}
int bl = 1;
for(i = 1; i < al; i++) {
if(a[i] != a[i-1]) {
a[bl++] = a[i];
}
}
return bl;
}

uint32_t pwm_get_mask(uint16_t value){
uint32_t mask = 0;
int i;
for(i=0; i<17; i++){
if((pwm_mask & (1 << i)) != 0 && pwm_values[i] == value) mask |= (1 << i);
}
return mask;
uint32_t pwm_get_mask(uint16_t value)
{
uint32_t mask = 0;
int i;
for(i=0; i<17; i++) {
if((pwm_mask & (1 << i)) != 0 && pwm_values[i] == value) {
mask |= (1 << i);
}
}
return mask;
}

void prep_pwm_steps(){
if(pwm_mask == 0){
pwm_steps_len = 0;
return;
}

int pwm_temp_steps_len = 0;
uint16_t pwm_temp_steps[17];
uint32_t pwm_temp_masks[17];

int i;
for(i=0; i<17; i++){
if((pwm_mask & (1 << i)) != 0 && pwm_values[i] != 0) pwm_temp_steps[pwm_temp_steps_len++] = pwm_values[i];
}
pwm_temp_steps[pwm_temp_steps_len++] = pwm_range;
pwm_temp_steps_len = pwm_sort_array(pwm_temp_steps, pwm_temp_steps_len) - 1;
for(i=0; i<pwm_temp_steps_len; i++){
pwm_temp_masks[i] = pwm_get_mask(pwm_temp_steps[i]);
}
for(i=pwm_temp_steps_len; i>0; i--){
pwm_temp_steps[i] = pwm_temp_steps[i] - pwm_temp_steps[i-1];
}
ETS_FRC1_INTR_DISABLE();
pwm_steps_len = pwm_temp_steps_len;
ets_memcpy(pwm_steps, pwm_temp_steps, (pwm_temp_steps_len + 1) * 2);
ets_memcpy(pwm_steps_mask, pwm_temp_masks, pwm_temp_steps_len * 4);
pwm_multiplier = ESP8266_CLOCK/(pwm_range * pwm_freq);
ETS_FRC1_INTR_ENABLE();
void prep_pwm_steps()
{
if(pwm_mask == 0) {
return;
}

int pwm_temp_steps_len = 0;
uint16_t pwm_temp_steps[17];
uint32_t pwm_temp_masks[17];
uint32_t range = pwm_range;

if((F_CPU / ESP8266_CLOCK) == 1) {
range /= 2;
}

int i;
for(i=0; i<17; i++) {
if((pwm_mask & (1 << i)) != 0 && pwm_values[i] != 0) {
pwm_temp_steps[pwm_temp_steps_len++] = pwm_values[i];
}
}
pwm_temp_steps[pwm_temp_steps_len++] = range;
pwm_temp_steps_len = pwm_sort_array(pwm_temp_steps, pwm_temp_steps_len) - 1;
for(i=0; i<pwm_temp_steps_len; i++) {
pwm_temp_masks[i] = pwm_get_mask(pwm_temp_steps[i]);
}
for(i=pwm_temp_steps_len; i>0; i--) {
pwm_temp_steps[i] = pwm_temp_steps[i] - pwm_temp_steps[i-1];
}

pwm_steps_changed = 0;
struct pwm_isr_table *table = &(_pwm_isr_data.tables[!_pwm_isr_data.active]);
table->len = pwm_temp_steps_len;
ets_memcpy(table->steps, pwm_temp_steps, (pwm_temp_steps_len + 1) * 2);
ets_memcpy(table->masks, pwm_temp_masks, pwm_temp_steps_len * 4);
pwm_multiplier = ESP8266_CLOCK/(range * pwm_freq);
pwm_steps_changed = 1;
}

void ICACHE_RAM_ATTR pwm_timer_isr(){
static uint8_t current_step = 0;
static uint8_t stepcount = 0;
static uint16_t steps[17];
static uint32_t masks[17];
if(current_step < stepcount){
T1L = (pwm_steps[current_step+1] * pwm_multiplier);
TEIE |= TEIE1;
if(masks[current_step] & 0xFFFF) GPOC = masks[current_step] & 0xFFFF;
if(masks[current_step] & 0x10000) GP16O = 0;
current_step++;
} else {
current_step = 0;
stepcount = 0;
if(pwm_mask == 0) return;
T1L = (pwm_steps[current_step] * pwm_multiplier);
TEIE |= TEIE1;
if(pwm_mask & 0xFFFF) GPOS = pwm_mask & 0xFFFF;
if(pwm_mask & 0x10000) GP16O = 1;
stepcount = pwm_steps_len;
memcpy(steps, pwm_steps, (stepcount + 1) * 2);
memcpy(masks, pwm_steps_mask, stepcount * 4);
}
void ICACHE_RAM_ATTR pwm_timer_isr() //103-138
{
struct pwm_isr_table *table = &(_pwm_isr_data.tables[_pwm_isr_data.active]);
static uint8_t current_step = 0;
TEIE &= ~TEIE1;//14
T1I = 0;//9
if(current_step < table->len) { //20/21
if(table->masks[current_step] & 0xFFFF) {
GPOC = table->masks[current_step] & 0xFFFF; //15/21
}
if(table->masks[current_step] & 0x10000) {
GP16O = 0; //6/13
}
current_step++;//1
} else {
current_step = 0;//1
if(pwm_mask == 0) { //12
table->len = 0;
return;
}
if(pwm_mask & 0xFFFF) {
GPOS = pwm_mask & 0xFFFF; //11
}
if(pwm_mask & 0x10000) {
GP16O = 1; //5/13
}
if(pwm_steps_changed) { //12/21
_pwm_isr_data.active = !_pwm_isr_data.active;
table = &(_pwm_isr_data.tables[_pwm_isr_data.active]);
pwm_steps_changed = 0;
}
}
T1L = (table->steps[current_step] * pwm_multiplier);//23
TEIE |= TEIE1;//13
}

void pwm_start_timer(){
timer1_disable();
timer1_attachInterrupt(pwm_timer_isr);
timer1_enable(TIM_DIV1, TIM_EDGE, TIM_SINGLE);
timer1_write(1);
void pwm_start_timer()
{
timer1_disable();
ETS_FRC_TIMER1_INTR_ATTACH(NULL, NULL);
ETS_FRC_TIMER1_NMI_INTR_ATTACH(pwm_timer_isr);
timer1_enable(TIM_DIV1, TIM_EDGE, TIM_SINGLE);
timer1_write(1);
}

extern void __analogWrite(uint8_t pin, int value) {
bool start_timer = false;
if(value == 0){
pwm_mask &= ~(1 << pin);
prep_pwm_steps();
digitalWrite(pin, LOW);
if(pwm_mask == 0) timer1_disable();
return;
}
if((pwm_mask & (1 << pin)) == 0){
if(pwm_mask == 0) start_timer = true;
pwm_mask |= (1 << pin);
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
}
pwm_values[pin] = value % (pwm_range + 1);
prep_pwm_steps();
if(start_timer){
pwm_start_timer();
}
extern void __analogWrite(uint8_t pin, int value)
{
bool start_timer = false;
if(value == 0) {
pwm_mask &= ~(1 << pin);
prep_pwm_steps();
digitalWrite(pin, LOW);
if(pwm_mask == 0) {
ETS_FRC_TIMER1_NMI_INTR_ATTACH(NULL);
timer1_disable();
timer1_isr_init();
}
return;
}
if((pwm_mask & (1 << pin)) == 0) {
if(pwm_mask == 0) {
memset(&_pwm_isr_data, 0, sizeof(struct pwm_isr_data*));
start_timer = true;
}
pwm_mask |= (1 << pin);
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
}
if((F_CPU / ESP8266_CLOCK) == 1) {
value = (value+1) / 2;
}
pwm_values[pin] = value % (pwm_range + 1);
prep_pwm_steps();
if(start_timer) {
pwm_start_timer();
}
}

extern void __analogWriteFreq(uint32_t freq){
pwm_freq = freq;
prep_pwm_steps();
extern void __analogWriteFreq(uint32_t freq)
{
pwm_freq = freq;
prep_pwm_steps();
}

extern void __analogWriteRange(uint32_t range){
pwm_range = range;
prep_pwm_steps();
extern void __analogWriteRange(uint32_t range)
{
pwm_range = range;
prep_pwm_steps();
}

extern void analogWrite(uint8_t pin, int val) __attribute__ ((weak, alias("__analogWrite")));
Expand Down

0 comments on commit 6feecc5

Please sign in to comment.