Jiamin’s Status Report for 11/14

This week was spent in preparation for the demo that was on Wednesday. For the beginning of this week, I started looking into how to implement SPI and UART for serial communication. But in the end, we stuck with I2C for the Nucleo to Jetson Nano communication. I spent a good amount of time in HH debugging with an RPI 4 to figure out i2cdetect by testing with internal vs. external resistors, the voltages, and signals of different things using an oscilloscope. There was weird behavior with the RPI with setting the slave address of the Nucleo and trying to i2cdetect. But when we tried this directly with the Jetson, it worked on both busses! We were able to run i2cdetect on the Nano with the intended slave address. I was able to HAL_I2C_Slave_Transmit() the UID of the RFID tag. This was originally tested in a separate environment so then I also took some time integrating I2C peripherals and logic into the actual NFC environment. I tested this RFID tag reader with the CMU student ID and it is able to read the tag of the CMU ID. With the FSM I wrote last week and a little debugging, we were able to get things to transmit. We also tested slave receive, in the case that we plan on having the Nucleo receive a signal from the Jetson. However, there was some strange behavior when Iris and Minji tried to concatenate things on their end, so that will require further debugging. In addition, last week I thought I was able to get the disable auto power on for Jetson to work, but I realized I made a mistake. It turned out that I was sending 3.3V to the GND pin of the Jetson. While it worked for the 2-3 tries I attempted, it didn’t feel stable as a long term solution. After I tested things out the a voltmeter and with the intended voltages on the pins, I was no longer able to get the “wake up” signal to work. Overall, I am on track since I was able to get all the functionalities I wanted to get done on the Nucleo except for the “wake up” signal. Next week, I will look more into this logic and start thinking more about the enclosing we want to make for our whole system. We talked with TechSpark, and they suggested that we can look for individual enclosing that already exists online, but I think we will have to design our own to account for the temperature sensor and Nucleo expansion board.

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