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MSP430F5172: OOK modulation scheme: How best to implement this in MSP430F51** family?

Part Number: MSP430F5172


Is there a way to implement an On-Off Keying modulation scheme using a module already existing within  this family of MCUs?  Alternately, are there any existing libraries that implement OOK already out there provided with Code Composer Studio which would work with this family of MCUs?

Specifically:   I have an external CMOS level reference clock @ 16MHz going into XT1 in High-Frequency, Bypass mode.   The 'sender' will be the MSP430 #1 driving an IR diode @ 56kHz, 50% duty cycle.   The 'receiver' will be a typical IR remote receiver such as any of Vishay's TSOP line; the receiver output goes into the input of another MSP430 (B)    These IR receivers use the modulated OOK signal @ 56kHz to reconstruct a data stream of some low bitrate -- a logic '1' when there is present the 56kHz carrier ... and a logic '0' in the absence of the same carrier.

I can think of ways to do this modulation using CCR's and timers, but it seems messy trying to roll a unique solution.  This topic is to discuss ways to implement OOK as described above by utilizing an existing module, or utilizing an ( unknown to me at this time ) existing library that implements the functionality.

  • Hi Adam,

    Unfortunately in F5172 there is no library that already implements the OOK modulation. The most convenient way to achieve OOK is just as you said -- use timer's CCR registers.

    However, if you are open to other MSP430 devices, you can find that in MSP430 FR2xx/4xx family devices there are "IR modulation" module, aiming at achieving ASK(OOK)/FSK modulation, by interconnecting on-chip timers. Also, there are code examples to help you do this for the FR2xx/4xx family devices.

    Put a snapshot here for your quick reference. For detailed information, you can refer to FR2xx/4xx devices User's Guide or specific datasheet.

    Regards,

    Harry

  • Thanks Harry!  I will take a look, and if I come across any stumbling blocks, will respond back to this thread.  
    Thank you for taking time to answer. 

  • Sure, please go ahead.

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