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MSP-EXP432P401R: ADC Inquiry

Part Number: MSP-EXP432P401R

Hi,

Good day.

Our customer would like to use the MSP-EXP432P401R and they have several inquiries about the ADV of this device. Kindly refer to their questions below.

1. What is the sampling rate of the inbuilt ADC?
2. How may channels does it got?
3. What is the sampling rate, minimum and maximum if we use 3 channels at the same time?
4.  Is it possible to plot these ADC values on Keil u4 or CSS?
5.  Can I plot them on LCD display, which is there on the shield?
6. How can I store these ADC Values?

Looking forward to your inputs. Thank you.


Regards,

Cedrick

  • Hello,

    1. What is the sampling rate of the inbuilt ADC?
    2. How may channels does it got?
    3. What is the sampling rate, minimum and maximum if we use 3 channels at the same time?

    Please refer to the datasheet and technical reference manual (TRM) for these details.

    4.  Is it possible to plot these ADC values on Keil u4 or CSS?

    See Section 7.7. Graph Tools in the CCS user's guide.

    5.  Can I plot them on LCD display, which is there on the shield?

    Yes. You can use the BOOSTXL-EDUMKII or BOOSTXL-K350QVG-S1.

    6. How can I store these ADC Values?

    You can store the ADC values in an array in RAM or write them to Flash memory. There should be some code examples in TI Resource Explorer that demonstrates this.

  • Hi James,

    Thank you for providing an answer to our question. I've got a feedback from our customer and they need further help on this. I hope you could help us. Kindly see their feedback below.

    4. (Contd...)
    (See Section 7.7. Graph Tools in the CCS user's guide. (software-dl.ti.com/.../ccs_debug-graphs.html
    In that link, it is mentioned that 6 types of graph tools are available. Four of them are related to FFT, which I am not looking for.
    I intend to plot the ADC sample value w.r.p. time, would like to know if it is possible in real-time?


    5. Thankyou, I can use this >> BOOSTXL-K350QVG-S1. But kindly let me know if I can plot the ADC values in real-time on that display booster pack.


    6. Yes, I am aware about the presence of ram. What if I am taking reading for a longer time say 4 days? I need a larger storage space right So, my question is can I interface it with any additional storage device like an SD card (16gb)?


    7. Can I interface this Launchpad with Raspberry Pi via any communication Protocol and send these ADC values from Launchpad to R-P and store it there?


    Thank you for your help.


    Regards,

    Cedrick

  • 4. The first two types describe what you're trying to accomplish. The ADC samples are discrete, not continuous. So, time would be represented by the array index. The refresh rate is limited to 100ms. From Section 7.7. Graph Tools in the CCS user's guide:

    Single Time. Single line graph that plots the array values in the “Y” axis and the array index (sample count) in the “X” axis.
    Dual Time. Dual line graph that plots two single time graphs in the same view.

    5. Yes, but you'll need to develop the code to do that. I would start with the MSP Graphics Library (MSP-GRLIB) example code.

    6. Based on your requirements (e.g. bits per sample, sampling frequency, number of samples), this will guide your decision on where to store the data. Onboard RAM and Flash will probably not be an option. Thus, you'd need to send data over SPI, UART or I2C to another device like RPi as you mentioned. Another option could be a SD card. See the fatsd example.

    7. Yes, if the RPi supports the interfaces mentioned in #6.