first, we design to check the first part of our circuit. it cost to much times in it. Finally, the circuit link and the voltage is normal, but RE200b did not work weather we touch or pass through it. in this case, we have to build the circuit again and change it little. the whole circuit divide into 3 parts from the difference amplifier and build it in difference breadboard. In this way, we can check the parts of the circuit and find the detail problem in this project. However, the first part of the circuit use the amplifier to the signal. the result is like the following picture.
this is the two picture about the oscilloscope screen. As we can see, when we pass through the re200B,it has a little change in the process. when we touch the re200b, the oscilloscope screen like following.
The difference is more obvious. our project has succeed in first part. Maybe next week we can finish it and go to test.