esp32-hal-dac.c

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "esp32-hal-dac.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "rom/ets_sys.h"
#include "esp_attr.h"
#include "esp_intr.h"
#include "soc/rtc_io_reg.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/sens_reg.h"

void IRAM_ATTR __dacWrite(uint8_t pin, uint8_t value)
{
    if(pin < 25 || pin > 26){
        return;//not dac pin
    }
    pinMode(pin, ANALOG);
    uint8_t channel = pin - 25;


    //Disable Tone
    CLEAR_PERI_REG_MASK(SENS_SAR_DAC_CTRL1_REG, SENS_SW_TONE_EN);

    if (channel) {
        //Disable Channel Tone
        CLEAR_PERI_REG_MASK(SENS_SAR_DAC_CTRL2_REG, SENS_DAC_CW_EN2_M);
        //Set the Dac value
        SET_PERI_REG_BITS(RTC_IO_PAD_DAC2_REG, RTC_IO_PDAC2_DAC, value, RTC_IO_PDAC2_DAC_S);   //dac_output
        //Channel output enable
        SET_PERI_REG_MASK(RTC_IO_PAD_DAC2_REG, RTC_IO_PDAC2_XPD_DAC | RTC_IO_PDAC2_DAC_XPD_FORCE);
    } else {
        //Disable Channel Tone
        CLEAR_PERI_REG_MASK(SENS_SAR_DAC_CTRL2_REG, SENS_DAC_CW_EN1_M);
        //Set the Dac value
        SET_PERI_REG_BITS(RTC_IO_PAD_DAC1_REG, RTC_IO_PDAC1_DAC, value, RTC_IO_PDAC1_DAC_S);   //dac_output
        //Channel output enable
        SET_PERI_REG_MASK(RTC_IO_PAD_DAC1_REG, RTC_IO_PDAC1_XPD_DAC | RTC_IO_PDAC1_DAC_XPD_FORCE);
    }
}

extern void dacWrite(uint8_t pin, uint8_t value) __attribute__ ((weak, alias("__dacWrite")));