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mirror of https://github.com/DCC-EX/CommandStation-EX.git synced 2024-12-23 12:51:24 +01:00

Fix to IO_DFPlayer.h - device was ignoring commands

The DFPlayer device does not like successive commands arriving to quickly after one another and may ignore a command.  The driver has been modified to enforce a delay between commands by sending pad characters where necessary.
This commit is contained in:
Neil McKechnie 2022-11-22 17:15:13 +00:00
parent f4aa572df2
commit 70203c3733

View File

@ -1,5 +1,5 @@
/*
* © 2021, Neil McKechnie. All rights reserved.
* © 2022, Neil McKechnie. All rights reserved.
*
* This file is part of DCC++EX API
*
@ -36,24 +36,31 @@
* In mySetup function within mySetup.cpp:
* DFPlayer::create(3500, 5, Serial1);
*
* Writing an analogue value 0-2999 to the first pin will select a numbered file from the SD card;
* Writing an analogue value 0-30 to the second pin will set the volume of the output;
* Writing a digital value to the first pin will play or stop the file;
* Writing an analogue value 1-2999 to the first pin (3500) will play the numbered file from the SD card;
* Writing an analogue value 0 to the first pin (3500) will stop the file playing;
* Writing an analogue value 0-30 to the second pin (3501) will set the volume;
* Writing a digital value of 1 to a pin will play the file corresponding to that pin, e.g.
the first file will be played by setting pin 3500, the second by setting pin 3501 etc.;
* Writing a digital value of 0 to any pin will stop the player;
* Reading a digital value from any pin will return true(1) if the player is playing, false(0) otherwise.
*
* From EX-RAIL, the following commands may be used:
* SET(3500) -- starts playing the first file on the SD card
* SET(3501) -- starts playing the second file on the SD card
* SET(3500) -- starts playing the first file (file 1) on the SD card
* SET(3501) -- starts playing the second file (file 2) on the SD card
* etc.
* RESET(3500) -- stops all playing on the player
* WAITFOR(3500) -- wait for the file currently being played by the player to complete
* SERVO(3500,23,0) -- plays file 23 at current volume
* SERVO(3500,23,30) -- plays file 23 at volume 30 (maximum)
* SERVO(3501,20,0) -- Sets the volume to 20
* SERVO(3500,2,Instant) -- plays file 2 at current volume
* SERVO(3501,20,Instant) -- Sets the volume to 20
*
* NB The DFPlayer's serial lines are not 5V safe, so connecting the Arduino TX directly
* to the DFPlayer's RX terminal will cause lots of noise over the speaker, or worse.
* A 1k resistor in series with the module's RX terminal will alleviate this.
*
* Files on the SD card are numbered according to their order in the directory on the
* card (as listed by the DIR command in Windows). This may not match the order of the files
* as displayed by Windows File Manager, which sorts the file names. It is suggested that
* files be copied into an empty SDcard in the desired order, one at a time.
*/
#ifndef IO_DFPlayer_h
@ -68,6 +75,19 @@ private:
uint8_t _inputIndex = 0;
unsigned long _commandSendTime; // Allows timeout processing
// When two commands are sent in quick succession, the device sometimes
// fails to execute one. A delay is required between successive commands.
// This could be implemented by buffering commands and outputting them
// from the loop() function, but it would somewhat complicate the
// driver. A simpler solution is to output a number of NUL pad characters
// between successive command strings if there isn't sufficient elapsed time
// between them. At 9600 baud, each pad character takes approximately
// 1ms to complete. Experiments indicate that the minimum number of pads
// for reliable operation is 17. This gives 17.7ms between the end of one
// command and the beginning of the next, or 28ms between successive commands
// being completed. I've allowed 20 characters, which is almost 21ms.
const int numPadCharacters = 20; // Number of pad characters between commands
public:
static void create(VPIN firstVpin, int nPins, HardwareSerial &serial) {
@ -83,8 +103,10 @@ protected:
addDevice(this);
}
void _begin() override {
_serial->begin(9600);
void _begin() override {
_serial->begin(9600, SERIAL_8N1); // 9600baud, no parity, 1 stop bit
// Flush any data in input queue
while (_serial->available()) _serial->read();
_deviceState = DEVSTATE_INITIALISING;
// Send a query to the device to see if it responds
@ -94,10 +116,10 @@ protected:
void _loop(unsigned long currentMicros) override {
// Check for incoming data on _serial, and update busy flag accordingly.
// Expected message is in the form "7F FF 06 3D xx xx xx xx xx EF"
// Expected message is in the form "7E FF 06 3D xx xx xx xx xx EF"
while (_serial->available()) {
int c = _serial->read();
if (c == 0x7E)
if (c == 0x7E && _inputIndex == 0)
_inputIndex = 1;
else if ((c==0xFF && _inputIndex==1)
|| (c==0x3D && _inputIndex==3)
@ -124,8 +146,8 @@ protected:
} else
_inputIndex = 0; // Unrecognised character sequence, start again!
}
// Check if the initial prompt to device has timed out. Allow 1 second
if (_deviceState == DEVSTATE_INITIALISING && currentMicros - _commandSendTime > 1000000UL) {
// Check if the initial prompt to device has timed out. Allow 5 seconds
if (_deviceState == DEVSTATE_INITIALISING && currentMicros - _commandSendTime > 5000000UL) {
DIAG(F("DFPlayer device not responding on serial port"));
_deviceState = DEVSTATE_FAILED;
}
@ -218,6 +240,7 @@ private:
void sendPacket(uint8_t command, uint16_t arg = 0)
{
unsigned long currentMillis = millis();
uint8_t out[] = { 0x7E,
0xFF,
06,
@ -231,7 +254,19 @@ private:
setChecksum(out);
// Check how long since the last command was sent.
// Each character takes approx 1ms at 9600 baud
unsigned long minimumGap = numPadCharacters + sizeof(out);
if (currentMillis - _commandSendTime < minimumGap) {
// Output some pad characters to add an
// artificial delay between commands
for (int i=0; i<numPadCharacters; i++)
_serial->write(0);
}
// Now output the command
_serial->write(out, sizeof(out));
_commandSendTime = currentMillis;
}
uint16_t calcChecksum(uint8_t* packet)