Internal functions of DFPlayer Mini Device driver. More...

Detailed Description

Internal functions of DFPlayer Mini Device driver.

Author: Marian Buschsieweke maria.nosp@m.n.bu.nosp@m.schsi.nosp@m.ewek.nosp@m.e@ovg.nosp@m.u.de

Definition in file dfplayer_internal.h.

#include <stdint.h>
#include "dfplayer_types.h"

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int	dfplayer_transceive (dfplayer_t dev, uint16_t resp, uint8_t cmd, uint8_t p1, uint8_t p2)
	Exchange a frame with the DFPlayer Mini. More...

int	dfplayer_file_cmd (dfplayer_t *dev, uint8_t cmd, uint8_t p1, uint8_t p2)
	Send a command selecting a playback file. More...

int	dfplayer_reset (dfplayer_t *dev)
	Reset the DFPlayer Mini MP3 player. More...

void	dfplayer_uart_rx_cb (void *dev, uint8_t data)
	UART-ISR handler of the DFPLayer driver. More...

static int	dfplayer_cmd_2param (dfplayer_t *dev, uint8_t cmd, uint8_t p1, uint8_t p2)
	Send a command with two parameters to the DFPlayer Mini. More...

static int	dfplayer_cmd_1param (dfplayer_t *dev, uint8_t cmd, uint8_t param)
	Send a command with one parameter to the DFPlayer Mini. More...

static int	dfplayer_cmd (dfplayer_t *dev, uint8_t cmd)
	Send a command without parameters to the DFPlayer Mini. More...

static int	dfplayer_query (dfplayer_t dev, uint16_t resp, uint8_t cmd)
	Send a query and receive the response. More...

Function Documentation

◆ dfplayer_cmd()

static int dfplayer_cmd	(	dfplayer_t *	dev,
		uint8_t	cmd
	)

inlinestatic

Send a command without parameters to the DFPlayer Mini.

Parameters

dev	Device descriptor of the DFPlayer to control
cmd	Command to send

Return values

0	Success
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out

Definition at line 187 of file dfplayer_internal.h.

◆ dfplayer_cmd_1param()

static int dfplayer_cmd_1param	(	dfplayer_t *	dev,
		uint8_t	cmd,
		uint8_t	param
	)

inlinestatic

Send a command with one parameter to the DFPlayer Mini.

Parameters

dev	Device descriptor of the DFPlayer to control
cmd	Command to send
param	The parameter to send

Return values

0	Success
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out

Definition at line 171 of file dfplayer_internal.h.

◆ dfplayer_cmd_2param()

static int dfplayer_cmd_2param	(	dfplayer_t *	dev,
		uint8_t	cmd,
		uint8_t	p1,
		uint8_t	p2
	)

inlinestatic

Send a command with two parameters to the DFPlayer Mini.

Parameters

dev	Device descriptor of the DFPlayer to control
cmd	Command to send
p1	First parameter to send
p2	Second parameter to send

Return values

0	Success
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out

Definition at line 153 of file dfplayer_internal.h.

◆ dfplayer_file_cmd()

int dfplayer_file_cmd	(	dfplayer_t *	dev,
		uint8_t	cmd,
		uint8_t	p1,
		uint8_t	p2
	)

Send a command selecting a playback file.

Parameters

dev	Device descriptor of the DFPlayer to control
cmd	Command starting playback of a file
p1	First parameter to send
p2	Second parameter to send

Return values

0	Success
-EINVAL	Called with invalid argument
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out
-ENOENT	No such file found

Warning: In contrast to all other functions in this header, this command does not lock and unlock the mutex in dev->mutex internally, but leaves this to the caller. This is required to do the booking of the currently played file consistent with the device state, even if multiple threads control the same DFPlayer.

◆ dfplayer_query()

static int dfplayer_query	(	dfplayer_t *	dev,
		uint16_t *	resp,
		uint8_t	cmd
	)

inlinestatic

Send a query and receive the response.

Parameters

dev	Device descriptor of the DFPlayer to control
resp	The response code will be stored here
cmd	Query-command to send

Return values

0	Success
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out

Definition at line 204 of file dfplayer_internal.h.

◆ dfplayer_reset()

int dfplayer_reset ( dfplayer_t * dev )

Reset the DFPlayer Mini MP3 player.

Parameters

dev	Device to reset

Return values

0	Success
-EINVAL	Called with invalid argument
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out

◆ dfplayer_transceive()

int dfplayer_transceive	(	dfplayer_t *	dev,
		uint16_t *	resp,
		uint8_t	cmd,
		uint8_t	p1,
		uint8_t	p2
	)

Exchange a frame with the DFPlayer Mini.

Parameters

dev	Device descriptor of the DFPlayer to control
resp	On success the response info is stored if `resp != NULL`
cmd	Command to send
p1	First parameter to send
p2	Second parameter to send

Return values

0	Success
-EINVAL	Called with invalid argument
-EAGAIN	Device responded with error busy
-EIO	Communication error
-ETIMEDOUT	Reply from the DFPlayer timed out

The frame format of the DFPlayer Mini is this:

 0                   1
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Start     |    Version    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Length    | Command/Code  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|    Feedback   |  Parameter 1  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Parameter 2  |   FCS (MSB)   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   FCS (LSB)   |    Stop       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

These are the values of the fields when sending a frame to the DFPlayer

Field	Value
Start	`0x7e`
Version	`0xff`
Length	Length of the data (always 6)
Command/Code	Command to send
Feedback	`0x01` if device should acknowledge command, `0x00` otherwise
Parameter 1	First parameter of the command, or `0x00`
Parameter 2	Second parameter of the command, or `0x00`
FCS	Frame check sequence, `0 - sum(data)`
Stop	`0xef`

These are the values of the fields when receiving a frame from the DFPlayer

Field	Value
Start	`0x7e`
Version	`0xff`
Length	Length of the data (always 6)
Command/Code	Response code (0x41 = success, 0x40 = error, 0x3* = event)
Feedback	`0x00`
Parameter 1	Additional info (most significant byte)
Parameter 2	Additional info (least significant byte)
FCS	Frame check sequence, `0 - sum(data)`
Stop	`0xef`

◆ dfplayer_uart_rx_cb()

void dfplayer_uart_rx_cb	(	void *	dev,
		uint8_t	data
	)

UART-ISR handler of the DFPLayer driver.

Parameters

dev	DFPlayer device descriptor for which a byte was received
data	The byte received over UART