Differences
This shows you the differences between two versions of the page.
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pm:lab:lab0xc0-6 [2020/04/26 18:27] alice_florenta.suiu [Example] |
pm:lab:lab0xc0-6 [2020/05/02 21:33] (current) dumitru.tranca [SPI (Serial Peripheral Interface)] |
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| Line 44: | Line 44: | ||
| For CPHA=0 data is **generated before the leading edge** (first edge of the clock), and is sampled on the leading edge (rising for CPOL=0 and falling for CPOL=1). | For CPHA=0 data is **generated before the leading edge** (first edge of the clock), and is sampled on the leading edge (rising for CPOL=0 and falling for CPOL=1). | ||
| - | For CPHA=0 data is **generated on the leading edge** (first edge of the clock), and is sampled on the trailing edge (falling for CPOL=0 and rising for CPOL=1). | + | For CPHA=1 data is **generated on the leading edge** (first edge of the clock), and is sampled on the trailing edge (falling for CPOL=0 and rising for CPOL=1). |
| + | |||
| + | CPOL and CPHA must be set accordingly to the SPI device configuration that we are communicating with. | ||
| + | E.g. If our uC communicates with an ADC that uses CPOL=1 and CPHA=1 it is mandatory to configure our SPI master in with the same parameters. | ||
| ===== SPI in Atmega324 ===== | ===== SPI in Atmega324 ===== | ||
| Line 100: | Line 103: | ||
| SPDR0 = data; | SPDR0 = data; | ||
| - | /* Wait for transmission complete */c | + | /* Wait for transmission complete */ |
| while(!(SPSR0 & (1 << SPIF0))); | while(!(SPSR0 & (1 << SPIF0))); | ||
| </code> | </code> | ||
| Line 112: | Line 115: | ||
| return SPDR0; | return SPDR0; | ||
| </code> | </code> | ||
| + | |||
| + | ===== Setup ===== | ||
| + | {{:pm:lab:spi11.png?900|}} | ||
| + | ===== Tasks ===== | ||
| + | Sketch is available here: {{:pm:lab:lab5.zip|}} | ||
| + | |||
| + | * Output Shift Register - {{http://www.ti.com/lit/ds/symlink/sn74hc595.pdf?ts=1587912861287&fbclid=IwAR0fUJqcsQ_rJIcTdt7z25uKUitrbiN3ye15k9VJgRcN0QAj4cDbKgaGzVA |74HC595 - Datasheet}} | ||
| + | * Input Shift Register - {{https://assets.nexperia.com/documents/data-sheet/74HC_HCT597.pdf?fbclid=IwAR1VcJfHyrg_61rOJah8WOFUdEidt7VKpIpAEb3FkntvsEeq6PMC810g1os |74HC597 - Datasheet}} | ||
| + | |||
| + | <hidden> | ||
| + | Solution is available here:{{:pm:lab:florin_salam_cel_mai_smecher_manelist.zip|}} | ||
| + | </hidden> | ||
| + | |||
| + | - To the PB0 pin there is connected an output shift register. The connection between the microcontroller and the shift register is established using SPI Bus topology. Initialize the SPI Protocol and display the message “SALAH” on the 7-segment display. Follow the comments marked with TODO 1 in the code skeleton. | ||
| + | - To the PB1 pin there is connected an input shift register. The connection between the microcontroller and the shift register is established using SPI Bus topology. Read the status of the buttons and turn on the LEDs associated with the pressed buttons. Follow the comments marked with TODO 2 in the code skeleton. | ||
| + | - SPI is a full-duplex protocol. Read the state of the buttons, turn on the LEDs associated with the pressed buttons and display the letter on the 7-segment display. Take the letter from the digits_pattern array based on the value resulted from pressing the buttons. Follow the comments marked with TODO 3 in the code skeleton. | ||
| + | |||
| + | Responsabil: [[alicesuiu17@gmail.com | Alice Suiu]] | ||
