Arduino: SoftwareSerial problem

[skeezoo]

Hi,
I am working with a wemos d1 board that s trying to communicate with a PZEM-004T
my IDE is 1.6.8 and esp8266 library 2.2.3 @9600 baud
I faced problems with Serial communication when receiving bytes . it just looked like rubbish.
tried a wemos d1 with a mega 2560 always the esp8266 receives wrong characters.
Double and trippled check all my configurations , but no difference.
Until I tried to use older version of SoftwareSerial. I replaced the SoftwareSerial library found in version 2.2.3 with the one in 2.0.0
and now everything works
when using any other different than 2.0.0 same issue
I even tried to used the latest IDE 1.6.10 but same issue.
anyone having problem with software serial library? I'm I missing some configuration?

Thanks

[9600]

You called?

[Sandiep]

Hi @skeezoo,

I have tested espsoftwareserial v3.1.0 with esp8266 v2.3.0 using Arduino IDE 1.6.10.
Following code seems to work fine.

#include <SoftwareSerial.h>

SoftwareSerial soft_serial(5,4);
void setup() {
  soft_serial.begin(9600);
}

void loop() {
  soft_serial.println("Hello World");
  delay(1000);
}

Can you share your code to regenerate issue?

Thanks.

[skeezoo]

@9600 sorry wrong number ;-)

@Sandiep thx for your help but found the solution in issue #1426
seems that @juancgalvez was working on a PZEM and solved it by adding half bit time delay just before starting to read bits
followed his recommendation and solved the problem
looks like a PZEM timing issue.
Thanks a lot juancgalvez

[crosofg]

@skeezoo can you share the pzem software serial with esp8266 code?

[skeezoo]

Hi @crosofg
sorry for late answer
here is a sample code

////////////////////very important for serial communication with PZM///////////////////////////////////////////////

include "SoftwareSerial.h" // used espsoftwareserial-master -> change in void ICACHE_RAM_ATTR SoftwareSerial::rxRead()-> m_bitTime/3 to m_bitTime/2

SoftwareSerial PZEMSerial(14, 12, false, 256);
uint8_t PZEM004T_Address[7]= {0xB4,0xC0,0xA8,0x01,0x01,0x00,0x1E};
uint8_t PZEM004T_VoltRequest[7]={0xB0,0xC0,0xA8,0x01,0x01,0x00,0x1A};
uint8_t PZEM004T_AmpRequest[7]={0xB1,0xC0,0xA8,0x01,0x01,0x00,0x1B};// C0 A8 01 01 00 1B
uint8_t PZEM004T_WattRequest[7]={0xB2,0xC0,0xA8,0x01,0x01,0x00,0x1C};//B2 C0 A8 01 01 00 1C
uint8_t PZEM004T_WattHourRequest[7]={0xB3,0xC0,0xA8,0x01,0x01,0x00,0x1D};//B3 C0 A8 01 01 00 1D

byte byPZEM004TResp,byPZEM004TReq;

float rVoltMain,rAmpsMain;
char strVolt[5] = "0";
char strAmp[5] = "0";
char strWatt[5] = "0";
char strWattHour[10] = "0";
byte rx_bytes[7];
bool bPZEMTxBusy,bPZEMRxTimeout,bDataAvailable,bPing;
unsigned long prevmillis,prevmillis1,prevmillis2,prevmillis3,prevmillis4,prevmillis5,prevmillis6;
int i;
uint32_t dnWattHour;
uint16_t nWatt;
char buf[100];

///////////////////////////////////////////////////////////////////////////////////////////////////////////////
//SETUP
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
void setup() {
Serial.begin(115200);
}

void loop() {
///////////////////////////////////////////////////////////////////////////////////
//PZEM Communication Fault
///////////////////////////////////////////////////////////////////////////////////
if ((millis() - prevmillis > 5000) && (bPZEMTxBusy)){
//detect and trigger fault , start req again
bPZEMTxBusy = false;
bPZEMRxTimeout = true;
//Reset Values read
rVoltMain = 0.0;
rAmpsMain = 0.0;
nWatt = 0;
byPZEM004TReq = 0;
Serial.println("PZEM RX timeout");
}

///////////////////////////////////////////////////////////////////////////////////
//Led Fast Flicker On PZEM RX timeout
///////////////////////////////////////////////////////////////////////////////////
if ((millis() - prevmillis1 > 50) && (bPZEMRxTimeout)){
//Toggle BuildIn Led
digitalWrite(BUILTIN_LED, !digitalRead(BUILTIN_LED));
prevmillis1 = millis();
}

///////////////////////////////////////////////////////////////////////////////////
// Send To PZEM Request
///////////////////////////////////////////////////////////////////////////////////
if ((millis() - prevmillis > 100) && (!bPZEMTxBusy)) {
bPZEMTxBusy = true;
switch (byPZEM004TReq) {
case 0:
PZEMSerial.write(PZEM004T_Address,sizeof(PZEM004T_Address));
//Serial.print("Addressreq @ ");
//Serial.println(millis());
break;
case 1:
PZEMSerial.write(PZEM004T_VoltRequest,sizeof(PZEM004T_VoltRequest));
//Serial.print("Vreq @ ");
Serial.println(millis());
break;
case 2:
PZEMSerial.write(PZEM004T_AmpRequest,sizeof(PZEM004T_AmpRequest));
//Serial.print("Areq @ ");Serial.println(millis());
break;
case 3:
PZEMSerial.write(PZEM004T_WattRequest,sizeof(PZEM004T_WattRequest));
//Serial.print("Wreq @ ");Serial.println(millis());
break;
case 4:
PZEMSerial.write(PZEM004T_WattHourRequest,sizeof(PZEM004T_WattHourRequest));
//Serial.print("Whreq @ ");Serial.println(millis());
break;
}
PZEMSerial.flush();
prevmillis = millis();
}

///////////////////////////////////////////////////////////////////////////////////
//Serial Receive from PZEM and Parse
///////////////////////////////////////////////////////////////////////////////////
i=0;
while (PZEMSerial.available() > 0) {
bDataAvailable = true;
rx_bytes[i++] = PZEMSerial.read();
delay(2);
}
//Evaluate Received Data
if (bDataAvailable){
bDataAvailable = false;
bPZEMTxBusy = false;
bPZEMRxTimeout = false;
//Serial.print("Received @ ");Serial.println(millis());
/* Serial.print(rx_bytes[0],HEX);
Serial.print(";");
Serial.print(rx_bytes[1],HEX);
Serial.print(";");
Serial.print(rx_bytes[2],HEX);
Serial.print(";");
Serial.print(rx_bytes[3],HEX);
Serial.print(";");
Serial.print(rx_bytes[4],HEX);
Serial.print(";");
Serial.print(rx_bytes[5],HEX);
Serial.print(";");
Serial.println(rx_bytes[6],HEX);*/
switch (rx_bytes[0]){
case 0xA0:
Serial.print("V = ");
//testFloat = (float)rx_bytes[2];//+(float)rx_bytes[3]/10;
rVoltMain = (float)rx_bytes[2]+(float)rx_bytes[3]/10.0;
memset(strVolt, 0, sizeof(strVolt));
dtostrf(rVoltMain,4,1,strVolt);
Serial.println(strVolt);
byPZEM004TReq = 2;
break;
case 0xA1:
Serial.print("A = ");
rAmpsMain = (float)rx_bytes[2]+(float)rx_bytes[3]/100.0;
memset(strAmp, 0, sizeof(strAmp));
dtostrf(rAmpsMain,4,2,strAmp);
Serial.println(rAmpsMain);
byPZEM004TReq = 3;
break;
case 0xA2:
Serial.print("W = ");
nWatt = ((uint16_t)rx_bytes[1]<<8) + (uint16_t)rx_bytes[2];
memset(strWatt, 0, sizeof(strWatt));
ltoa((uint16_t)nWatt,strWatt,10);
Serial.println(strWatt);
byPZEM004TReq = 4;
break;
case 0xA3:
Serial.print("Wh = ");
dnWattHour = ((uint32_t)rx_bytes[1]<<16) + ((uint32_t)rx_bytes[2]<<8) + (uint32_t)rx_bytes[3];
memset(strWattHour, 0, sizeof(strWattHour));
ltoa(dnWattHour,strWattHour,10);
Serial.println(strWattHour);
Serial.println("");
byPZEM004TReq = 1;
break;
case 0xA4:
if (rx_bytes[6]=0xA4){
Serial.print("Address Ok ");
byPZEM004TReq = 1;
}
else Serial.print("Address not Defined ");
}

}

}//End of Loop

[devyte]

Per previous comments, closing as resolved.