You will design a data-acquisition system to measure force. The range of force is -10 to 10 N. The force signal exists in the 0 to 99 Hz frequency band. You will measure the ADC at a fixed rate, convert each sample to signed decimal fixed point, and write each fixed-point measurement into global variable called Force (which is the integer part of the fixed-point number). The ADC sampling must occur in real-time using an output compare periodic interrupt Channel 5.
a) Choose the sampling rate. Explain why you chose that value.
b) The sensitivity of the bridge output is 0.025 V/N, meaning the differential voltage (V2-V1) varies from -0.25 to +0.25 V. However, both V1 and V2 are around 2.5 V (more specifically V2 varies from 2.375 to 2.625 V, while V1 varies from 2.625 to 2.375
V). A good CMRR is required. Design the analog circuit mapping the bridge output into the ADC input Channel 3. (You do not have to add an antialiasing analog low-pass filter.) Show chip numbers, resistor values, but not pin numbers.
c) Assuming the only error occurs in the 10-bit ADC, what is the expected force measurement resolution in Newtons (N)?
d) Write the entire program that implements this real-time data-acquisition system. You are allowed to call the following functions (without showing the implementations of these functions).
![542_e6ea557f-6a03-41ec-9c44-1de73cef952b.png](https://secure.tutorsglobe.com/CMSImages/542_e6ea557f-6a03-41ec-9c44-1de73cef952b.png)
If you need other functions, you will have to show their implementations. Be sure to include the software that maps unsigned ADC (0 to 1023) into a signed fixed point (resolution you choose in part c). Include the output-compare 5 initialization and ISR.