Skip to content

Commit

Permalink
Add support for DFPlayer modules using a MH2024K-16SS chip (#77)
Browse files Browse the repository at this point in the history 
* Autoformat code

* Refactor DfMp3_Packet from enum to struct

* Add option to send a packet without checksum

* Play finished event on MH2024K-16SS is code 0x4c

* Reformat using another formatter (in vscode => vcFormat)

* Replace C-style casts to their C++ equivalent

* On MH2024K-16SS, the end of song USB, is 0x4b instead of 0x3c...

* Use a pointer instead of a ref to make it explicit that the packet is changed

* Refactor calcChecksum to use a for-loop to reduce program size (48 bytes => 36 bytes)

* Use templating to reduce code and memory size

* Do not init buffer to save program size.

* Remove DfMp3_Packet and declare types in Chip classes

* Rename field SendCheckSum

* Renamed i variable with a more meaningful name (packetByte)

* fix warnings

* Move the generation of the packet to the Mp3Chip classes

* Add missing const

Co-authored-by: Maxime Chéramy <maxime@cheramy.org>
  • Loading branch information
@MaximeCheramy
MaximeCheramy and Maxime Chéramy committed Aug 30, 2021
1 parent 81692ad commit d603f8e
Showing 1 changed file with 119 additions and 78 deletions.
197 changes: 119 additions & 78 deletions src/DFMiniMp3.h
View file
Expand Up @@ -43,7 +43,6 @@ enum DfMp3_Error
DfMp3_Error_General = 0xff
};


enum DfMp3_PlaybackMode
{
DfMp3_PlaybackMode_Repeat,
Expand All @@ -52,7 +51,6 @@ enum DfMp3_PlaybackMode
DfMp3_PlaybackMode_Random
};


enum DfMp3_Eq
{
DfMp3_Eq_Normal,
Expand All @@ -76,12 +74,114 @@ enum DfMp3_PlaySources // bitfield - more than one can be set
{
DfMp3_PlaySources_Usb = 0x01,
DfMp3_PlaySources_Sd = 0x02,
DfMp3_PlaySources_Pc = 0x04,
DfMp3_PlaySources_Pc = 0x04,
DfMp3_PlaySources_Flash = 0x08,
};

// 7E FF 06 0F 00 01 01 xx xx EF
// 0 -> 7E is start code
// 1 -> FF is version
// 2 -> 06 is length
// 3 -> 0F is command
// 4 -> 00 is no receive
// 5~6 -> 01 01 is argument
// 7~8 -> checksum = 0 - ( FF+06+0F+00+01+01 )
// 9 -> EF is end code
struct DfMp3_Packet_WithCheckSum
{
uint8_t startCode;
uint8_t version;
uint8_t length;
uint8_t command;
uint8_t requestAck;
uint8_t hiByteArgument;
uint8_t lowByteArgument;
uint8_t hiByteCheckSum;
uint8_t lowByteCheckSum;
uint8_t endCode;
};
struct DfMp3_Packet_WithoutCheckSum
{
uint8_t startCode;
uint8_t version;
uint8_t length;
uint8_t command;
uint8_t requestAck;
uint8_t hiByteArgument;
uint8_t lowByteArgument;
uint8_t endCode;
};


uint16_t calcChecksum(const DfMp3_Packet_WithCheckSum& packet)
{
uint16_t sum = 0xFFFF;
for (const uint8_t* packetByte = &(packet.version); packetByte != &(packet.hiByteCheckSum); packetByte++) {
sum -= *packetByte;
}
return sum + 1;
}

void setChecksum(DfMp3_Packet_WithCheckSum* out)
{
uint16_t sum = calcChecksum(*out);

out->hiByteCheckSum = (sum >> 8);
out->lowByteCheckSum = (sum & 0xff);
}

template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
bool validateChecksum(const DfMp3_Packet_WithCheckSum& in)
{
uint16_t sum = calcChecksum(in);
return (sum == static_cast<uint16_t>((in.hiByteCheckSum << 8) | in.lowByteCheckSum));
}

class Mp3ChipMH2024K16SS {
public:
static const bool SendCheckSum = false;

typedef DfMp3_Packet_WithoutCheckSum SendPacket;
typedef DfMp3_Packet_WithCheckSum ReceptionPacket;

static const SendPacket generatePacket(uint8_t command, uint16_t arg) {
return {
0x7E,
0xFF,
6,
command,
0,
static_cast<uint8_t>(arg >> 8),
static_cast<uint8_t>(arg & 0x00ff),
0xEF };
}
};

class Mp3ChipOriginal {
public:
static const bool SendCheckSum = true;

typedef DfMp3_Packet_WithCheckSum SendPacket;
typedef DfMp3_Packet_WithCheckSum ReceptionPacket;

static const SendPacket generatePacket(uint8_t command, uint16_t arg) {
SendPacket packet = {
0x7E,
0xFF,
6,
command,
0,
static_cast<uint8_t>(arg >> 8),
static_cast<uint8_t>(arg & 0x00ff),
0,
0,
0xEF };
setChecksum(&packet);
return packet;
}
};

template <class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD, class T_CHIP_VARIANT = Mp3ChipOriginal>
class DFMiniMp3
{
public:
explicit DFMiniMp3(T_SERIAL_METHOD& serial) :
Expand All @@ -100,7 +200,7 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3

void loop()
{
while (_serial.available() >= DfMp3_Packet_SIZE)
while (_serial.available() >= static_cast<int>(sizeof(typename T_CHIP_VARIANT::ReceptionPacket)))
{
listenForReply(0x00);
}
Expand Down Expand Up @@ -260,7 +360,6 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
return static_cast<DfMp3_Eq>(listenForReply(0x44));
}


void setPlaybackSource(DfMp3_PlaySource source)
{
sendPacket(0x09, source, 200);
Expand Down Expand Up @@ -368,31 +467,6 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
private:
static const uint16_t c_msSendSpace = 50;

// 7E FF 06 0F 00 01 01 xx xx EF
// 0 -> 7E is start code
// 1 -> FF is version
// 2 -> 06 is length
// 3 -> 0F is command
// 4 -> 00 is no receive
// 5~6 -> 01 01 is argument
// 7~8 -> checksum = 0 - ( FF+06+0F+00+01+01 )
// 9 -> EF is end code
enum DfMp3_Packet
{
DfMp3_Packet_StartCode,
DfMp3_Packet_Version,
DfMp3_Packet_Length,
DfMp3_Packet_Command,
DfMp3_Packet_RequestAck,
DfMp3_Packet_HiByteArgument,
DfMp3_Packet_LowByteArgument,
DfMp3_Packet_HiByteCheckSum,
DfMp3_Packet_LowByteCheckSum,
DfMp3_Packet_EndCode,
DfMp3_Packet_SIZE
};


T_SERIAL_METHOD& _serial;
uint32_t _lastSend; // not initialized as agreed in issue #63
uint16_t _lastSendSpace;
Expand All @@ -408,18 +482,7 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3

void sendPacket(uint8_t command, uint16_t arg = 0, uint16_t sendSpaceNeeded = c_msSendSpace)
{
uint8_t out[DfMp3_Packet_SIZE] = { 0x7E,
0xFF,
06,
command,
00,
static_cast<uint8_t>(arg >> 8),
static_cast<uint8_t>(arg & 0x00ff),
00,
00,
0xEF };

setChecksum(out);
typename T_CHIP_VARIANT::SendPacket packet = T_CHIP_VARIANT::generatePacket(command, arg);

// wait for spacing since last send
while (((millis() - _lastSend) < _lastSendSpace))
Expand All @@ -431,14 +494,14 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
}

_lastSendSpace = sendSpaceNeeded;
_serial.write(out, DfMp3_Packet_SIZE);
_serial.write(reinterpret_cast<uint8_t*>(&packet), sizeof(packet));

_lastSend = millis();
}

bool readPacket(uint8_t* command, uint16_t* argument)
{
uint8_t in[DfMp3_Packet_SIZE] = { 0 };
typename T_CHIP_VARIANT::ReceptionPacket in;
uint8_t read;

// init our out args always
Expand All @@ -449,7 +512,7 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
do
{
// we use readBytes as it gives us the standard timeout
read = _serial.readBytes(&(in[DfMp3_Packet_StartCode]), 1);
read = _serial.readBytes(&in.startCode, 1);

if (read != 1)
{
Expand All @@ -458,19 +521,19 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3

return false;
}
} while (in[DfMp3_Packet_StartCode] != 0x7e);
} while (in.startCode != 0x7e);

read += _serial.readBytes(in + 1, DfMp3_Packet_SIZE - 1);
if (read < DfMp3_Packet_SIZE)
read += _serial.readBytes(&in.version, sizeof(in) - 1);
if (read < sizeof(in))
{
// not enough bytes, corrupted packet
*argument = DfMp3_Error_PacketSize;
return false;
}

if (in[DfMp3_Packet_Version] != 0xFF ||
in[DfMp3_Packet_Length] != 0x06 ||
in[DfMp3_Packet_EndCode] != 0xef)
if (in.version != 0xFF ||
in.length != 0x06 ||
in.endCode != 0xef)
{
// invalid version or corrupted packet
*argument = DfMp3_Error_PacketHeader;
Expand All @@ -484,8 +547,8 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
return false;
}

*command = in[DfMp3_Packet_Command];
*argument = ((in[DfMp3_Packet_HiByteArgument] << 8) | in[DfMp3_Packet_LowByteArgument]);
*command = in.command;
*argument = ((in.hiByteArgument << 8) | in.lowByteArgument);

return true;
}
Expand All @@ -508,10 +571,12 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3
switch (replyCommand)
{
case 0x3c: // usb
case 0x4b: // usb on MH2024K-16SS
T_NOTIFICATION_METHOD::OnPlayFinished(*this, DfMp3_PlaySources_Usb, replyArg);
break;

case 0x3d: // micro sd
case 0x4c: // micro sd on MH2024K-16SS
T_NOTIFICATION_METHOD::OnPlayFinished(*this, DfMp3_PlaySources_Sd, replyArg);
break;

Expand Down Expand Up @@ -560,28 +625,4 @@ template<class T_SERIAL_METHOD, class T_NOTIFICATION_METHOD> class DFMiniMp3

return 0;
}

uint16_t calcChecksum(uint8_t* packet)
{
uint16_t sum = 0;
for (int i = DfMp3_Packet_Version; i < DfMp3_Packet_HiByteCheckSum; i++)
{
sum += packet[i];
}
return -sum;
}

void setChecksum(uint8_t* out)
{
uint16_t sum = calcChecksum(out);

out[DfMp3_Packet_HiByteCheckSum] = (sum >> 8);
out[DfMp3_Packet_LowByteCheckSum] = (sum & 0xff);
}

bool validateChecksum(uint8_t* in)
{
uint16_t sum = calcChecksum(in);
return (sum == static_cast<uint16_t>((in[DfMp3_Packet_HiByteCheckSum] << 8) | in[DfMp3_Packet_LowByteCheckSum]));
}
};

0 comments on commit d603f8e

Please sign in to comment.