Multiple Strain Gauges

Jonthornham

Other Parts Discussed in Thread: MSP430F47176

I am working on a project where I am using multiple strain gauges (4 or 5). I am new to MCU's so I have a couple basic questions. After reading MSP430 Microcontroller Basics I am convinced I should be using a 16 Bit Sigma-Delta Converter. My questions has to do with how many SD16_A's I need. My first thought is to use one SD16_A for each strain gauge. I will be taking an average of the measurements and sending them to a wireless radio for transmission at 4 Hz. I like the looks of the MSP430F47176 which has 6 SD16_A's.

Is my thinking to have on SD16_A per strain gauge correct and do you like the look of the MSP430 above? Is there a more intelligent way to average the readings from the multiple stain gauges with fewer SD16_A's that I am missing?

Take care,

Jon

over 14 years ago

0 Jason Kriek over 14 years ago

TI__Expert 5180 points

Jon,

This comes down to a matter of preference. If you use a SD16 for each channel, you will get faster results since you wont have to switch through the gauges through an analog mux.

You have to look at other things when picking the micro such as how much RAM you might need or how much Flash you might need. If you are going to be doing things with wireless, you need to make sure that you will have enough memory resources to run the stack.

I noticed from you other post that you were lookign at ant. If you take a look at the ez430-rf2500 eval kit, it gives you the ability to sample all the strain gauges and also do the RF connection back to a PC. It also has the debugger in this kit that you can attach to the radio and use as an access point to bring data into the pc. The difference with this kit is that it has 10 bit SAR ADC's instead of 16 bit.

You can find info on the kit here:

http://focus.ti.com/docs/toolsw/folders/print/ez430-rf2500.html

Feel free to ask any more questions!

-Jason

0 Jonthornham over 14 years ago in reply to Jason Kriek

Expert 1490 points

Jason,

Thanks. So the MSP-FET430U100A does not have a debugger? I am coming from the software world so I thought it was in CCS4. Apparently I am wrong. Can I add a debugger to the MSP-FET430U100A?

Take care,

Jon

0 Jonthornham over 14 years ago in reply to Jonthornham

Expert 1490 points

Sorry, I just realized the MSP-FET430UIF does the debugging.

Take care,

Jon

0 Jason Kriek over 14 years ago in reply to Jonthornham

TI__Expert 5180 points

No Problem, the kit you are looking at comes with the debugger and the target board. So you would be good to go if you should choose that route!

-Jason

0 Jonthornham over 14 years ago in reply to Jason Kriek

Expert 1490 points

Thanks Jason.

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Multiple Strain Gauges