Launchpad Serial Comms Baud Rate Issue Energia

[RenierSF1 0]

I have a launchpad V1.4 and V1.5. I am sending serial data from the launchpad at 9600 baud and using a FT232 and Putty to decode the serial data. However, the serial communication does not work at a baud rate of 9600. I have to set the baud rate in Putty to 4800 in order to get it to work. Somehow the launchpad reverts the baud rate back to 4800.

 

If I set the bad rate on the Launchpad and Putty to 2400 or 4800, all works fine. Only 9600 and higher that does not work. 

Having the same problem when using TimerSerial.h. The jumper settings on both Launchpads are correct.

 

Being fairly new to the Energia and Launchpad, are there any other registers that I need  to set? Probelms in my code?

Will appreciate any help. Thanks

 

Code:

 

 

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


void loop() 
{
  Serial.print("Hello World");      
  delay(500);
  Serial.println("...??");
  delay(500);
}

Edited April 23, 2013 by bluehash
Please use code tags next time.

[Rickta59 589]

If you are using a g2231 it will automatically limit the speed to 4800 max.  Which chip are you using?

[RenierSF1 0]

I am using the MSP430G2553 that came with the launchpad v1.5.

[roadrunner84 466]

@@Rickta59 why could the g2231 only do 4800 baud? The chip is fast enough, and so is the peripheral afaik.

[Rickta59 589]

@@roadrunner84 I err on the side of caution.  The msp430g2231 chips only have the 1MHz pre-calibrated DCO value from the factory.  Energia uses a Timer based serial UART implementation for those chips.  We don't know what activities the user is going to do.  104usec isn't that many instructions to handle incoming serial data, send outgoing UART serial data, handle the watchdog, and handle any port attached interrupts written by the user.

 

https://github.com/energia/Energia/blob/master/hardware/msp430/cores/msp430/TimerSerial.cpp

line 106 is where I limit the speed if you are running at 1MHz. A person using the msp430g2231 could remove the restriction by changing that code.

 

@@RenierSF1 my guess is that you have the wrong chip selected in Energia. You might check and make sure you have the g2553 selected

[RenierSF1 0]

@@RenierSF1 my guess is that you have the wrong chip selected in Energia. You might check and make sure you have the g2553 selected

 

Yes, indeed, G2231 selected and not g2253...Rookie mistake...Serial is running at 9600 baud now. Thanks!! :thumbup:

[energia 485]

Thanks for reporting back @@RenierSF1 and letting us know that you got it to work. This makes me wonder if the selected board indication needs a more prominent place in the IDE.