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I needed to be able to watch signals from hundreds of Hz  to 10Khz . While reading the msp430 family manual found the Data Transfer Controller (DTC) that can be put to work with the ADC . 

 

So the original launchscope by NJC streams data one sample at a time , and that is why it is so slow . So using the DTC we can actually get near the 200Ksps . 

 

So I use an array of 200 integers (400 Bytes . I didn't want to leave the launchpad without ram, just 512B for the msp430g2553

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  • 1 month later...

Hey @@simpleavr, the datasheet of the msp430g2553 says the ADC is capable of "up to 200ksps", that means, a 10Khz signal will have only 20 samples of resolution (at max sampling speed) for a complete wave (so it is not gonna look smooth at all) . So a 200KHz signal should seem like a square wave . But that wouldn't be helpful nor reliable for signal viewing.  

 

I don't know why the limit is at 200ksps and I don't know what would happen if you try to sample at , say, 1Msps, using the 16Mhz config. Since I am using the burst mode (with the DTC) I don't know either if the msp430g2553 will let you use more than this limit (as I said I only achieved 180ksps, and I didn't see if it was the clock's fault) . But it can use any clock source within the micro . so theoretically it is possible :) . Let me know if you achieve higher samples per second 

 

The stellaris, though, seems like a much better option for this.

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thanks for your reply.

 

actually the slau144 says "greater than" 200ksps. so that's why i wonder "how much greater".

 

at about 200ksps u would fill up 200 samples in 1/1000 sec.

 

uart at 9600bps u xfer 200 x 5 bytes (4 hex char + line feed) = 1kbytes = 8k bits or about 1 second to xfer result. i.e. 1 sec refresh.

 

did u try to make in continuous and does it look good (or useful to u)?

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