CE 433 Spring 2022
SPI Tutorial
Taylor Nakai
tsnakai@fortlewis.edu

Introduction:
In this homework, we worked on the basics and implementing the PmodALS ambient light sensor so that an 8-bit binary number (0-255) light intensity number is read in. SPI is a synchronous communication protocol allowing for data to be transmitted and received at the same time. To be able to use the PmodALS ambient light sensor, we had to use the SPI Light Sensor module, the SPI Leader Receiver module, the Binary to BCD module, the Seven Segment Driver module, and the Decoder Seven Segment module. We were tasked with displaying the 8-bit value on the Seven Segment Display and the LEDs of the Basys 3.

Task 1:
In Task 1, had us go over some basics associated with SPI. We learned about how many wires are required for SPI, how the data packet size is not constant in SPI, how SCK is generated, and the transmission and reception operations assciated with SPI. Figure 1 shows the MOSI of the leader and follower. Figure 2 shows the MISO of the leader and the follower.


Figure 1. Code implementing the MOSI of the leader and follower.


Figure 2. Code implementing the MISO off the leader and follower.

Task 2:
In Task 2, we were given the task of displaying the 8-bit ambient light sensor value on the Seven Segment Display and the LEDs of the Basys 3. To be able to use the PmodALS ambient light sensor, we had to use the SPI Light Sensor module, the SPI Leader Receiver module, the Binary to BCD module, the Seven Segment Driver module, and the Decoder Seven Segment module. Figure 3 is the code needed to be able to use the ambient light sensor, the only module not shown is the SPI Leader Receiver which is shown above in Figure 2.


Figure 3. Code needed to be able to use the ambient light sensor.


Figure 4. Demonstation of using the ambient light sensor with the Basys 3.

Discussion:
By completing this homwork, it allowed me to become more comfortable using the ambient light module, the SPI protocals associated with the Basys3. I really enjoyed doing this homework as learning more about SPI was interesting and seeing the ambient light value displayed on the LEDs and Seven Segment Display. I really liked this tutorial as it was something that I never have explored. Overall, I think this homework was a great introduction into using the SPI protocal that the Basys3 has to offer.
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