MSP-EXP430G2ET: Serial.print() not working. Nothing is being printed on Serial Monitor

Did you set the baud rate on the terminal to match your program?

Hi,

I checked the following,

Kept the jumpers in the same direction as other jumpers. Same result, nothing printed on Serial monitor after reading a pin continuously.

Rotated the jumpers by 90 deg. And tried sending characters from Serial monitor didn't get any echo.

As you said, there are two COM ports MSP Application UART1 and MSP Debug Interface. Tried opening the serial monitor on MSP Debug Interface port (higher number). Still no result.

I downloaded the latest version of Energia. It has the MSP-EXP430G2ET board listed.

MSP Application UART1 and MSP Debug Interface 

Hi Stefan,

Any ideas on this? The problem isn't solved yet

When I

1) Rotated the TXD and RXD jumpers on J101(/J105) so that they were perpendicular to all the others

2) Selected the "Application UART" COM port

3) Ran the sketch below with Energia 1.8.7E21 (October 2018) on an MSP-EXP430G2ET Launchpad

I got a (fast) sequence of "Hi" messages.

I'm not sure what we're doing differently.

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println("Hi");
  delay(1);
}

I'm following the same, but getting no result. I have attached the picture of my board. Am I missing anything?

Hi Avinash,

sorry for the late reply as i was offline for a while.

I assume that this issue is still not solved.

I checked again that schematic of the launchpad and realized that this as a few things a little bit different then most others.

So to do a loop back on the UART on the PC side you need to connect the UART pins in a cross. So

RXD on the USB side with TXD on the MSP 430 side

TXD on the USB side with RXD on the MSP 430 side

This will generate the loopback on both sides.

If you now open a terminal on the PC you should see that any typed character is echoed / displayed in the receive window.

With this short Energia code you can test the same on the MSP430 side. If the loopback is OK the RED LED should be on

#define LED RED_LED

void setup()
{
  // start serial port at 9600 bps:
  Serial.begin(9600);

  // initialize the digital pin as an output.
  pinMode(LED, OUTPUT);     
}

void loop()
{
  // if we get a valid byte, read analog ins:
  if (Serial.available() > 0) {
    if (Serial.read() == 'A')
    {
        digitalWrite(LED, HIGH);   // turn the LED on (HIGH is the voltage level)
    }
  }else{
        digitalWrite(LED, LOW);    // turn the LED off by making the voltage LOW
    }
  Serial.print('A'); // send a capital A
  delay(300);
}

Regards,

 Stefan

Hi Stefan,

Thanks for your reply. I am unable to understand what you imply on the following,

RXD on the USB side with TXD on the MSP 430 side

TXD on the USB side with RXD on the MSP 430 side

How to actually connect the Jumper pins?

I connected the RXD, TXD in cross like an X (not vertical or horizontal) in the following manner using jumper wires. Then tried your program. When I press 'A' or any other key and send. I get a junk value back as a reply on the Serial monitor. Attached the screenshot below

Hi Stefan,

The problem isn't resolved yet. In the last picture that I had sent, the LED was on due to previously tried Blink example program and other sample programs for testing. It didnt get turned on when i sent the characters from serial monitor.

However when I tried in another PC, I received back the characters sent on the serial monitor correctly (not any junk characters). But  the LED didn't glow though. I then switched the jumpers back to horizontal position (HW UART) and tried the AnalogReadSerial sketch. Still no output on serial monitor.

Driver version from device manager: 1.4.0.0

Tried both the COM ports MSP Application UART1 and MSP Debug Interface.

Hi Avinash,

thanks for testing.

So we know that:

The communication part of the Serial on the PC side of the Launchpad is OK.

Your first PC you used for testing seems to have a problem with the driver (you may can try again with the loopback and selecting the other available serial ports if not already done. I see a similar behavior when i select the wrong com port).

The real issues seems to be on the MSP430 side on the Launchpad. The question is why the loopback is not working here. There are mainly two options for that:
- the MSP430 got damaged and one of the IOs do not work. (could be checked with replacing the device)
- there is a connection issue on the PCB. May you have a Multimeter available to check the connection between:
  - Pin 3 on the MSP430 socket to pin 5 on J101 (Header with jumpers)
  - Pin 4 on the MSP430 socket to pin 8 on J101 (Header with jumpers)

Regards,

 Stefan