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[issue letscontrolit#914] _P053_PMSx003 Dust Sensor looses sync
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- Use peek instead of read, to make sure a complete packet is in the buffer.
- Flush buffer after processing a packet.
- Increased software serial buffer to the size of 3 packets.
- Peek (+ read garbage) 10 times per second to get the buffer in sync to start with start byte of packet.
- Decent delete + clean up of software serial allocation when changing settings (prevent memory leak)
- Move log String allocation to inside scope of function, not permanent allocated.
- Split into separate functions to make it better readable.
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@TD-er
TD-er committed Feb 28, 2018
1 parent a938bc7 commit 1a44ed6
Showing 1 changed file with 101 additions and 81 deletions.
182 changes: 101 additions & 81 deletions src/_P053_PMSx003.ino
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Original file line number Diff line number Diff line change
Expand Up @@ -66,42 +66,103 @@ void SerialRead16(uint16_t* value, uint16_t* checksum)
#endif
}

void SerialFlush() {
if (swSerial != NULL) {
swSerial->flush();
} else {
Serial.flush();
}
}

boolean PacketAvailable(void)
{
boolean success = false;

if (swSerial != NULL) // Software serial
{
// When there is enough data in the buffer, search through the buffer to
// find header (buffer may be out of sync)
while (swSerial->available() >= PMSx003_SIZE)
{
if (swSerial->read() == PMSx003_SIG1 && swSerial->read() == PMSx003_SIG2)
{
success = true;
break;
}
if (!swSerial->available()) return false;
while ((swSerial->peek() != PMSx003_SIG1) && swSerial->available()) {
swSerial->read(); // Read until the buffer starts with the first byte of a message, or buffer empty.
}
if (swSerial->available() < PMSx003_SIZE) return false; // Not enough yet for a complete packet
}
else // Hardware serial
{
// When there is enough data in the buffer, search through the buffer to
// find header (buffer may be out of sync)
while (Serial.available() >= PMSx003_SIZE)
{
if (Serial.read() == PMSx003_SIG1 && Serial.read() == PMSx003_SIG2)
{
success = true;
break;
}
if (!Serial.available()) return false;
while ((Serial.peek() != PMSx003_SIG1) && Serial.available()) {
Serial.read(); // Read until the buffer starts with the first byte of a message, or buffer empty.
}
if (Serial.available() < PMSx003_SIZE) return false; // Not enough yet for a complete packet
}
return success;
return true;
}

boolean Plugin_053_process_data(struct EventStruct *event) {
String log;
uint16_t checksum = 0, checksum2 = 0;
uint16_t framelength = 0;
uint16 dummy;
SerialRead16(&dummy, &checksum); // read PMSx003_SIG1 + PMSx003_SIG2
SerialRead16(&framelength, &checksum);
if (framelength != (PMSx003_SIZE - 4))
{
log = F("PMSx003 : invalid framelength - ");
log += framelength;
addLog(LOG_LEVEL_ERROR, log);
return false;
}

uint16_t data[13]; // byte data_low, data_high;
for (int i = 0; i < 13; i++)
SerialRead16(&data[i], &checksum);

log = F("PMSx003 : pm1.0=");
log += data[0];
log += F(", pm2.5=");
log += data[1];
log += F(", pm10=");
log += data[2];
log += F(", pm1.0a=");
log += data[3];
log += F(", pm2.5a=");
log += data[4];
log += F(", pm10a=");
log += data[5];
addLog(LOG_LEVEL_DEBUG, log);

log = F("PMSx003 : count/0.1L : 0.3um=");
log += data[6];
log += F(", 0.5um=");
log += data[7];
log += F(", 1.0um=");
log += data[8];
log += F(", 2.5um=");
log += data[9];
log += F(", 5.0um=");
log += data[10];
log += F(", 10um=");
log += data[11];
addLog(LOG_LEVEL_DEBUG_MORE, log);

// Compare checksums
SerialRead16(&checksum2, NULL);
SerialFlush(); // Make sure no data is lost due to full buffer.
if (checksum == checksum2)
{
// Data is checked and good, fill in output
UserVar[event->BaseVarIndex] = data[3];
UserVar[event->BaseVarIndex + 1] = data[4];
UserVar[event->BaseVarIndex + 2] = data[5];
values_received = true;
return true;
}
return false;
}

boolean Plugin_053(byte function, struct EventStruct *event, String& string)
{
String log;
boolean success = false;

switch (function)
Expand Down Expand Up @@ -153,12 +214,18 @@ boolean Plugin_053(byte function, struct EventStruct *event, String& string)
int txPin = Settings.TaskDevicePin2[event->TaskIndex];
int resetPin = Settings.TaskDevicePin3[event->TaskIndex];

log = F("PMSx003 : config ");
String log = F("PMSx003 : config ");
log += rxPin;
log += txPin;
log += resetPin;
addLog(LOG_LEVEL_DEBUG, log);

if (swSerial != NULL) {
// Regardless the set pins, the software serial must be deleted.
delete swSerial;
swSerial = NULL;
}

// Hardware serial is RX on 3 and TX on 1
if (rxPin == 3 && txPin == 1)
{
Expand All @@ -171,7 +238,7 @@ boolean Plugin_053(byte function, struct EventStruct *event, String& string)
{
log = F("PMSx003: using software serial");
addLog(LOG_LEVEL_INFO, log);
swSerial = new ESPeasySoftwareSerial(rxPin, txPin);
swSerial = new ESPeasySoftwareSerial(rxPin, txPin, false, 96); // 96 Bytes buffer, enough for up to 3 packets.
swSerial->begin(9600);
swSerial->flush();
}
Expand All @@ -192,76 +259,29 @@ boolean Plugin_053(byte function, struct EventStruct *event, String& string)
success = true;
break;
}

case PLUGIN_EXIT:
{
if (swSerial)
{
delete swSerial;
swSerial=NULL;
}
break;
}

// The update rate from the module is 200ms .. multiple seconds. Practise
// shows that we need to read the buffer many times per seconds to stay in
// sync.
case PLUGIN_TEN_PER_SECOND:
{
if (Plugin_053_init)
{
uint16_t checksum = 0, checksum2 = 0;
uint16_t framelength = 0;
uint16_t data[13];
// byte data_low, data_high;
int i = 0;

// Check if a packet is available in the UART FIFO.
// Check if a complete packet is available in the UART FIFO.
if (PacketAvailable())
{
log = F("PMSx003 : Packet available");
addLog(LOG_LEVEL_DEBUG_MORE, log);
checksum += PMSx003_SIG1 + PMSx003_SIG2;
SerialRead16(&framelength, &checksum);
if (framelength != (PMSx003_SIZE - 4))
{
log = F("PMSx003 : invalid framelength - ");
log += framelength;
addLog(LOG_LEVEL_ERROR, log);
break;
}

for (i = 0; i < 13; i++)
SerialRead16(&data[i], &checksum);

log = F("PMSx003 : pm1.0=");
log += data[0];
log += F(", pm2.5=");
log += data[1];
log += F(", pm10=");
log += data[2];
log += F(", pm1.0a=");
log += data[3];
log += F(", pm2.5a=");
log += data[4];
log += F(", pm10a=");
log += data[5];
addLog(LOG_LEVEL_DEBUG, log);

log = F("PMSx003 : count/0.1L : 0.3um=");
log += data[6];
log += F(", 0.5um=");
log += data[7];
log += F(", 1.0um=");
log += data[8];
log += F(", 2.5um=");
log += data[9];
log += F(", 5.0um=");
log += data[10];
log += F(", 10um=");
log += data[11];
addLog(LOG_LEVEL_DEBUG_MORE, log);

// Compare checksums
SerialRead16(&checksum2, NULL);
if (checksum == checksum2)
{
// Data is checked and good, fill in output
UserVar[event->BaseVarIndex] = data[3];
UserVar[event->BaseVarIndex + 1] = data[4];
UserVar[event->BaseVarIndex + 2] = data[5];
values_received = true;
success = true;
}
addLog(LOG_LEVEL_DEBUG_MORE, F("PMSx003 : Packet available"));
success = Plugin_053_process_data(event);
}
}
break;
Expand Down

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