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VCC like the voltage?

 

There's no way to control this in Energia (or any other way of programming). If you are looking for a way to connect peripherals at other voltages than what the MSP430 runs on (approx. 3V), you'll need to use level convertors:

 

Theory:

http://www.ti.com/lit/an/slaa148/slaa148.pdf

 

Or buy/build something like these:

https://www.sparkfun.com/products/8745

http://www.adafruit.com/products/757

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Are you serious? Of course the voltage is settable on the Launchpad. The range is 1.8V - 3.6V. It's a flag for mspdebug. The question is just how to do it from Energia.

$ mspdebug --help
Usage: mspdebug [options] <driver> [command ...]


...

 

   -v voltage
        Set the supply voltage, in millivolts.
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Ok, I was afraid that might be the case that it could not be changed from software.

 

But IDEs like CCS or IAR can set the VCC of a Launchpad. How is this happening then, and can it be done from Energia?

TI's professional JTAG programmer for the MSP430, called the FET430UIF, has the ability to supply a Vcc rail to its target chip that is changeable in software, using mspdebug or CCS or IAR. This programmer costs ~$110 I think.

 

The MSP430 LaunchPad includes a "lite" version of that FET that TI produced years ago for their eZ430 series. This "FET lite" does not include the ability to produce a software-settable Vcc rail. TI chose instead to ship the LaunchPad with a TPS77336 voltage regulator which has a fixed output voltage of 3.6V.

 

So the vcc setting in mspdebug et al is indeed there, just not supported (doesn't actually do anything) on the LaunchPad. And as a result the Energia developers saw no reason to support the feature inside the IDE.

 

Sent from my Galaxy Note II with Tapatalk

 

 

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Could you let us know what you want to do? Is it a DAC like application?

 

 

Sure.

 

No, nothing to do with DAC.

 

I just play with external ICs requiring different voltages, which I would prefer to power from the Launchpad's VCC pin. Also, lowering the VCC as much as possible preserves energy for running on batteries, solar power, etc.

 

 

TI's professional JTAG programmer for the MSP430, called the FET430UIF, has the ability to supply a Vcc rail to its target chip that is changeable in software, using mspdebug or CCS or IAR. This programmer costs ~$110 I think.

 

The MSP430 LaunchPad includes a "lite" version of that FET that TI produced years ago for their eZ430 series. This "FET lite" does not include the ability to produce a software-settable Vcc rail. TI chose instead to ship the LaunchPad with a TPS77336 voltage regulator which has a fixed output voltage of 3.6V.

 

So the vcc setting in mspdebug et al is indeed there, just not supported (doesn't actually do anything) on the LaunchPad. And as a result the Energia developers saw no reason to support the feature inside the IDE.

 

Sent from my Galaxy Note II with Tapatalk

 

I see. Thank you very much for that detailed explanation. For some reason I was sure I had found it to be settable previously. But I do also have a FET430UIF and target board, so I must have gotten the memories mixed together.

 

By the way, I use your excellent nRF24L01+ driver library, so thank you very much for that also! :)

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Sure.

No, nothing to do with DAC.

I just play with external ICs requiring different voltages, which I would prefer to power from the Launchpad's VCC pin. Also, lowering the VCC as much as possible preserves energy for running on batteries, solar power, etc.

 

 

 

I see. Thank you very much for that detailed explanation. For some reason I was sure I had found it to be settable previously. But I do also have a FET430UIF and target board, so I must have gotten the memories mixed together.

 

By the way, I use your excellent nRF24L01+ driver library, so thank you very much for that also! :)

Ah k well, you can turn verbose on in Energia's preferences.txt file and see where Energia ends up storing its compiled binary (in the build messages in the bottom pane), then use mspdebug and the FET430UIF to program your MSP430 instead (disconnect onboard FET jumpers and run jumper wires from the FET430 incl. VCC TOOL) using the 'tilib' driver. Lots of manual work but it will give you the ability to run Energia sketches at voltages of your choosing :)

 

Sent from my Galaxy Note II with Tapatalk

 

 

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