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Unread 05-05-2015, 18:23
philso philso is offline
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Re: Using the TI LaunchPad from your KoP

Quote:
Originally Posted by ILAMtitan View Post
Philso,
The Launchpad would be a perfect platform for what you're trying to do. The only issue you might run into using the booster packs you've found that I see is that they will both probably use the same SPI port. You would have to double check the pin-outs to ensure that the chip select lines are on different pins so you can mux them properly. I've worked with RobG and BlueHash from 43oh before though, and they are both great resources.

It looks like RobG made a booster pack that integrates the SD and LCD into a single design: https://www.tindie.com/products/RobG...d-card-socket/
You might want to take a look at that one to see if it will meet your requirements.

Another consideration to make is how accurate you need your current measurements. The Launchpad that we put in the KoP is the MSP430F5529, which has 12 bit SAR converters. We just recently launched the MSP432P401 LP which has 14bit converters that might give you some additional dynamic range/accuracy if needed. In addition, that board has the new MSP432 processor, which is a 48MHz 32bit Cortex M4F. The additional clock speed should also give you higher resolution PWMs (but I haven't looked into this specific feature).

Both of the Launchpads listed will also include an internal RTC capable of making accurate time stamps for your data logger. You can either set it to the current data/time, or just use it in free run mode as you described. I'm not personally familiar with designing and operating a DC current source via PWM, but I can ask around the 430 team to see if anyone has information I can share if that would help.
Thanks for your quick reply, Bart.

The MSP432P401 LP, with the 14-Bit ADC and PWM and internal RTC looks very attractive at just a few dollars more.

I had chosen the LCD with the touch screen to avoid needing to add a keyboard or keypad. I will check the chip select lines used by the two booster packs. I am guessing that if they conflict, I should be able to modify one of them to use a different GPIO pin.

I have done a bit of reading about the SD card booster pack and am a bit confused. It appears that the software currently can only read from the SC card and cannot write a file or it cannot create a file from scratch on the SD card. Is this true?
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