This week was designated to achieve a smooth movement of the hand and arm. We found that it is best to use a 20 ms delay between steps of the servos to make the movement look more smooth. We found that the shoulder servos will not support the desired movement. It doesn’t have enough torque to support the weight of the arm and also doesn’t rotate a full 180 degrees. This limits the use of the prosthetic arm and doesn’t fully mimic a human arm. Therefore, we decided to replace the shoulder servos with DC motors. Research was done this week too to find what servos are attached to the arm and the voltage range they are allowed. The last page in the scanned notebook found below is the week update presented to the class and instructor. 

Scanned Notebook: Week-12

This week was used to research frequencies related to EMG/EEG signals. We found from the brain stem study results that the signals send at 1 kHz and the values range from +- 1.3 mV. Also, we found that we need an analog to digital converter and the Raspberry Pi does not have one so a shield that offered this function was ordered. 

Scanned Notebook: Week-11