115 lines
2.7 KiB
C
115 lines
2.7 KiB
C
/* Implementation of Delta-Sigma modulator support.
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*
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* Part of esp-open-rtos
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* Copyright (C) 2018 ourairquality (https://github.com/ourairquality)
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* Copyright (C) 2018 Zaltora (https://github.com/Zaltora)
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* BSD Licensed as described in the file LICENSE
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*/
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#include "dsm.h"
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#include <espressif/esp_common.h>
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#include <esp8266.h>
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#ifdef DSM_DEBUG
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#define debug(fmt, ...) printf("%s: " fmt "\n", "DSM", ## __VA_ARGS__)
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#else
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#define debug(fmt, ...)
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#endif
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typedef struct dsmInfoDefinition
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{
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uint8_t running;
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uint8_t preScale;
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uint8_t dutyCycle;
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bool output;
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/* private */
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uint8_t usedPins;
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uint8_t pins[8];
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} DSMInfo;
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static DSMInfo dsmInfo;
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void dsm_init(uint8_t npins, const uint8_t* pins)
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{
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/* Assert number of pins is correct */
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if (npins > MAX_DSM_PINS)
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{
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debug("Incorrect number of PWM pins (%d)\n", npins);
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return;
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}
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/* Save pins information */
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dsmInfo.usedPins = npins;
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for (uint8_t i = 0 ; i < npins; ++i)
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{
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dsmInfo.pins[i] = pins[i];
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/* configure GPIOs */
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gpio_enable(pins[i], GPIO_OUTPUT);
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}
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/* Set output to LOW */
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dsm_stop();
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/* Flag not running */
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dsmInfo.running = 0;
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}
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// Freq = (80,000,000/prescale) * (target / 256) HZ (0 < target < 128)
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// Freq = (80,000,000/prescale) * ((256 - target) / 256) HZ (128 < target < 256)
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void dsm_set_prescale(uint8_t prescale)
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{
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//TODO: Add a freq/prescale converter
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dsmInfo.preScale = prescale;
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debug("Set Prescale: %u",dsmInfo.preScale);
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}
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// Freq = (80,000,000/prescale) * (target / 256) HZ (0 < target < 128)
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// Freq = (80,000,000/prescale) * ((256 - target) / 256) HZ (128 < target < 256)
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void dsm_set_target(uint8_t target)
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{
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dsmInfo.dutyCycle = target;
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if (target == 0 || target == UINT8_MAX)
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{
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dsmInfo.output = (target == UINT8_MAX);
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}
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debug("Duty set at %u",dsmInfo.dutyCycle);
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if (dsmInfo.running)
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{
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dsm_start();
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}
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}
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void dsm_start()
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{
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if (dsmInfo.dutyCycle > 0 && dsmInfo.dutyCycle < UINT8_MAX)
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{
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for (uint8_t i = 0; i < dsmInfo.usedPins; ++i)
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{
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SET_MASK_BITS(GPIO.CONF[dsmInfo.pins[i]], GPIO_CONF_SOURCE_PWM);
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}
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GPIO.PWM = GPIO_PWM_ENABLE | (dsmInfo.preScale << 8) | dsmInfo.dutyCycle;
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}
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else
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{
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for (uint8_t i = 0; i < dsmInfo.usedPins; ++i)
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{
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gpio_write(dsmInfo.pins[i], dsmInfo.output );
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}
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}
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debug("start");
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dsmInfo.running = 1;
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}
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void dsm_stop()
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{
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for (uint8_t i = 0; i < dsmInfo.usedPins; ++i)
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{
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CLEAR_MASK_BITS(GPIO.CONF[dsmInfo.pins[i]], GPIO_CONF_SOURCE_PWM);
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gpio_write(dsmInfo.pins[i], false);
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}
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debug("stop");
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dsmInfo.running = 0;
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}
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