Sarah’s Status Update 11/11

This week, we had our interim demonstrations, so I worked on getting ready for that. I set up a breadboard with 4 touch sensors and 3 flex sensors and connected them all to the ESP32. However, the flex sensors’ resistance was too large to be recognized by the ESP. I then added 10K Ohm resistors in parallel for each flex sensor to lower the effective resistance of each flex sensor circuit. Additionally, when combining all the sensors on the same power line, there seemed to be the same problem with too much resistance on each line. I then added 10K Ohm resistors in parallel for each sensor, which seemed to solve our problem. We also received our IMU earlier this week. Since the communication between the ESP and IMU is I2C, I created an I2C scanner to find the peripheral address of the IMU. I then read through the IMU manuals to figure out how to enable and display the readings from each sensor on the IMU. Since the IMU is the only peripheral on the I2C bus, I treated it as a sensor and constantly polled for data. This eliminated the need for interrupts, so the only wires connecting the ESP and the IMU are power, mode selection for the communication protocol, and the data and clock lines. We ended up implementing a library especially designed for the FSM300, which allowed us to print gyroscope and accelerometer readings to the serial display. After adding in the resistors to the demo breadboard, I updated the PCB files to include these added resistors, using SMD 0805 10K resistors. For ease of use and to make our entire footprint smaller, I sent out the files for the PCB to be fabricated, and I expect this order to arrive early next week. I also placed an order for the correct resistors needed as I will do the PCB assembly by hand. Finally, I tested out the battery life needed for the entire system, and found that the battery life lasted for over 15 hours with about 7500 mAh of charge. Next week, I will start assembling the PCB, attaching the sensors to the glove, and do some more stress testing on the battery so we can hopefully order either a small power bank or lithium ion battery for the final project. We are on schedule to finish on time.