MSP430F5510: USB CDC send data as soon as port has been opened on host

Yannik Muendler

Prodigy 305 points

Part Number: MSP430F5510

Hallo everyone,

i am trying to accomplish the same as in the referred thread.

As soon as the host pc open the port to the MSP i want to send some data.

I can't get the code from Reto Truninger to work. How to proceed?

In USBCdc.c i have this function.

void usbSetControlLineState (void)
{
	USBCDC_handleSetControlLineState((uint8_t)tSetupPacket.wIndex,
            (uint8_t)tSetupPacket.wValue);
    usbSendZeroLengthPacketOnIEP0();                                        //Send ZLP for status stage
}

so i have to set a variable depending of tSetupPacket.wValue & 0x01; in this function?

and call this function in the main usbSetControlLineState()?

after that i can send data in an if with the variable as condition?

Thank you in advance

over 6 years ago

0 Christopher Vendette over 6 years ago

TI__Intellectual 2315 points

An MSP team member has been assigned to review your issue. Please expect a response shortly.

0 Wei.Jetim Zhao over 6 years ago

TI__Genius 13215 points

Hi Yannik,

We have USB developer's package for MSP430 which you could get the programmer's guide for how to create your code.

http://dev.ti.com/tirex/explore/node?node=ALU3cM-tEnLiutYtes7CuA__IOGqZri__LATEST

0 Yannik Muendler over 6 years ago in reply to Wei.Jetim Zhao

TI__Prodigy 305 points

Hi Wei,

thanks for your response,

Yes I read throuth the document, with my code I already can communicate with the msp430.

But I want to react on the event of open port from the host.

DTR signaling is available on the device side, to know the timing when PC application opens / closes the COM port.

Hyperterminal sets DTR to 1 at its startup, and it drops DTR to 0 at exit.

DTR signaling is passed to device over Set_Control_Line_State request.

DTR signaling (0 or 1) is held at the bit 0 of (BYTE)tSetupPacket.wValue, when your custom usbSetControlLineState() is called by the stack.

When trying to set a variable depending of tSetupPacket.wValue & 0x01

the variable has no value and hovering over tSetupPacket gives me following img.

0 Wei.Jetim Zhao over 6 years ago in reply to Yannik Muendler

TI__Genius 13215 points

Hi Yannik,

Sorry for reply late.

Please refer to below thread which could give you suggestion about "Error: cannot load from non-primitive location".

https://e2e.ti.com/support/tools/ccs/f/81/p/3325/141182

0 Yannik Muendler over 6 years ago in reply to Wei.Jetim Zhao

TI__Prodigy 305 points

Thanks for your reply,

i got it solved in some way, it works now with putty (Flow Control set to NONE or XON/XOFF)

static uint8_t detectopenport=0;
uint8_t usbSetControlLineState (void)
{
    detectopenport=tSetupPacket.wValue & 0x01;
	USBCDC_handleSetControlLineState((uint8_t)tSetupPacket.wIndex,
            (uint8_t)tSetupPacket.wValue);
    usbSendZeroLengthPacketOnIEP0();                                       
    return (FALSE);
}


uint8_t USBCDC_getDTRstate(void)
{
    return detectopenport;
}

and in main.c (needed "firstprint", because Putty seems to hold "detectopenport" true as long as the port is open)

switch (USB_getConnectionState()){
                     case ST_ENUM_ACTIVE:{
                         static uint16_t firstprint=0;
                         if(USBCDC_getDTRstate()&&(firstprint==0))
                          {
                              //Data you want to print
                              firstprint = 1;
                          }
                         if (!USBCDC_getDTRstate())
                         {firstprint=0;
                         }

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MSP430F5510: USB CDC send data as soon as port has been opened on host