nuttx/boards/xtensa/esp32/common/include/esp32_board_dac.h
Tomáš Pilný 3e85c1886e esp32/dac-one-shot: lower-half driver for ESP32 internal DAC
Enable with ./tools/configure.sh -l esp32-devkitc:dac
DAC channel 0 = GPIO 25
DAC channel 1 = GPIO 26
default path: /dev/dac0

Resolution 8 bits = values 0~255
Voltage: 0~Vref

The reference voltage 'Vref' here is input from the pin VDD3P3_RTC
which ideally equals to the power supply VDD (3.3V).
2024-02-02 09:23:28 -08:00

85 lines
3.1 KiB
C

/****************************************************************************
* boards/xtensa/esp32/common/include/esp32_board_dac.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
#ifndef __BOARDS_XTENSA_ESP32_COMMON_INCLUDE_ESP32_DAC_H
#define __BOARDS_XTENSA_ESP32_COMMON_INCLUDE_ESP32_DAC_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Type Definitions
****************************************************************************/
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Inline Functions
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: board_dac_initialize
*
* Description:
* Initialize and register the Digital to Analog Convertor (DAC) driver.
*
* Input Parameters:
* path - The device number, used to build the device path as
* /dev/dacN
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int board_dac_initialize(const char *path);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __BOARDS_XTENSA_ESP32_COMMON_INCLUDE_ESP32_DAC_H */