MSP430F5172: Reading specific A2D inputs (in sequence sampling)

Itay Kalfa

Part Number: MSP430F5172

Hi,

I'm using MSP430F5172 for my project. I'm using the DMA to read the A2D signals and its work fine, my issue is with all the analog inputs that I'm reading for nothing...

I need to read Analog input at A1 ,A5, A8.... As I understand it the DMA work on a range of A2D inputs (means that I need to read all inputs from A0 to A8 for those 3 inputs) and I can't specific write the inputs that I want...

Is that correct? or maybe I just misunderstanding and missing something here...

Thank you very much for your help.

over 9 years ago

0 Ryan Brown1 over 9 years ago

TI__Guru**** 223077 points

Hi Itay,

As explained in Section 27.2.7.2 of the User's Guide, a sequence begins with the channel selected by the ADC10INCHx bits and decrements to channel A0. It is therefore not possible to only sample/convert specific channels, every channel in between must be included in the sequence as well.

Regards,
Ryan

0 Itay Kalfa over 9 years ago in reply to Ryan Brown1

Prodigy 240 points

Hi Ryan,

Thank you for the comment.

If I want to use the sequence mode and my higher channel is A8, but I use A1 for SPI communication (SIMO), dose the A2D scan can ruin my SPI BUS?

0 Ryan Brown1 over 9 years ago in reply to Itay Kalfa

TI__Guru**** 223077 points

Hi Itay,

SIMO and an analog input cannot share the same pin, but ports 1 through 3 are port mappable so you can move the SPI communication functionality to different pins. Please refer to Section 6.9.2 of the Datasheet, Section 13 of the User's Guide, and the C code examples software package.

Regards,
Ryan

0 Itay Kalfa over 9 years ago in reply to Ryan Brown1

Prodigy 240 points

Thank you very much Ryan, it's help a lot !

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MSP430F5172: Reading specific A2D inputs (in sequence sampling)