Serial communications Issues

Hi Jeffdseattle ,

To help check and replicate the issue, can you kindly send a photo or provide the exact setup of the UART connection you've made from CN0359 J2 to your arduino pins.

And can you also send your serial terminal settings in Putty. Thank you.

Regards,
Andy

Hello, for UART I have Arduino TX -> pin 2, RX->pin 4, common-> pin 5. For Putty 115200 Baud, 8 data, 1 stop, Parity None. Implicit CR every LF checked, Local Echo force on, local line ending forced on. 

thanks

Hi Jeffdseattle ,

Thank you for your quick response.

I'll get back to you today once we've setup the board.

Thanks,
Andy

Thank, you for your help!

Hi Jeffdseattle ,

We were able to successfully establish serial communication with the CN0359 Rev B using a USB to UART cable. The Putty settings are as follows:

Then, to enter a command:

1. Type the command. For this example: "poll".
2. Press "Ctrl" + "J".
3. Hit Enter.

Can you check and test this using Putty for now while we check on the Arduino code?

Thanks,
Andy

Hello, well adding the Cntrl-J in there worked! I thought Putty was sending \n from the settings made in the Terminal tab. Oh well, at least it is working now with Putty. Thank you very much for your help and if you have any ideas on the Arduino issue I am having that would be great too, ultimately I would like to run with embedded system. 

I really appreciate the help!

I thought I'd would add my Arduino code that I am trying to use below.

String inputString = ""; // a String to hold incoming data
bool stringComplete = false; // whether the string is complete

void setup() {
// initialize serial:
Serial.begin(115200,SERIAL_8N1);
// reserve 200 bytes for the inputString:
inputString.reserve(8192);

}

void loop() {
// print the string when a newline arrives:
if (stringComplete) {
Serial.println(inputString);
// clear the string:
inputString = "";
stringComplete = false;

}

Serial.write("poll\n");
delay(1000);
}

/*
SerialEvent occurs whenever a new data comes in the hardware serial RX. This
routine is run between each time loop() runs, so using delay inside loop can
delay response. Multiple bytes of data may be available.
*/
void serialEvent() {
while (Serial.available()>0) {
// get the new byte:
char inChar = (char)Serial.read();

inputString += inChar;
//Serial.println(inChar);
// if the incoming character is a newline, set a flag so the main loop can
// do something about it:

if (inChar == '\n') {

stringComplete = true;

}
}
}

REPLY (Only three lines in replay form CN0359):

EXC V: 1.050000V

EXC FREQ: 100.000000Hz

EXC setup time: 10.0000

Sorry for all of the messages but I am also having an issue with the Arduino sketch locking up the CN0359 board. It must be something in my sketch since it will not lock up if I have the RX/TX/GND pins connected when running Blink program for instance. When I run the serial sketch it locks the board up randomly and quits responding to serial. Also, the LCD screen freezes and does not show any updates. Thanks

Hi Jeffdseattle ,

Thanks for sharing your setup. One quick thing to try have you tried reducing or removing the delay() in your loop? A long delay can prevent the Arduino from reading incoming UART data quickly enough, potentially causing the receive buffer to overflow and missing part of the response.

You may also check this closed EZ thread which discusses a similar issue: (+) CN0359 UART issue - Q&A - Precision Microcontrollers - EngineerZone

Please do not hesitate to provide an update here.

Regards,
Andy

Hello, Yes I did try to remove the delay but that did not help. Ultimately the issue was that I was using the only UART that I had available on the UNO so switched to one of my ESP32 boards and had one TX/RX for Serial.print() and the other for the Serial.write() commands to the board. All good now for comms, I just have to figure out how to parse the data to get mainly to the Conductivity measurement which should be pretty simple. Thanks!

Hello, Yes I did try to remove the delay but that did not help. Ultimately the issue was that I was using the only UART that I had available on the UNO so switched to one of my ESP32 boards and had one TX/RX for Serial.print() and the other for the Serial.write() commands to the board. All good now for comms, I just have to figure out how to parse the data to get mainly to the Conductivity measurement which should be pretty simple. Thanks!