Added spi/spi_master_slave. (#101)
Co-authored-by: Michael Stoops <spam@michaelstoops.com>
This commit is contained in:
Michael Stoops
GitHub
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@ -9,7 +9,7 @@ on getting up and running.
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App|Description | Link to prebuilt UF2
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---|---|---
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[hello_serial](hello_world/serial) | The obligatory Hello World program for Pico (Output over serial version) |
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[hello_serial](hello_world/serial) | The obligatory Hello World program for Pico (Output over serial version) |
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[hello_usb](hello_world/usb) | The obligatory Hello World program for Pico (Output over USB version) | https://rptl.io/pico-hello-usb
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[blink](blink) | Blink an LED on and off. | https://rptl.io/pico-blink
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@ -44,7 +44,6 @@ App|Description
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[control_blocks](dma/control_blocks)| Build a control block list, to program a longer sequence of DMA transfers to the UART.
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[channel_irq](dma/channel_irq)| Use an IRQ handler to reconfigure a DMA channel, in order to continuously drive data through a PIO state machine.
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### Flash
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App|Description
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@ -71,7 +70,6 @@ App|Description
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---|---
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[hello_divider](divider) | Show how to directly access the hardware integer dividers, in case AEABI injection is disabled.
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### I2C
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App|Description
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@ -99,7 +97,7 @@ App|Description
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App|Description
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---|---
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[hello_multicore](multicore/hello_multicore) | Launch a function on the second core, printf some messages on each core, and pass data back and forth through the mailbox FIFOs.
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[multicore_fifo_irqs](multicore/multicore_fifo_irqs) | On each core, register and interrupt handler for the mailbox FIFOs. Show how the interrupt fires when that core receives a message.
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[multicore_fifo_irqs](multicore/multicore_fifo_irqs) | On each core, register and interrupt handler for the mailbox FIFOs. Show how the interrupt fires when that core receives a message.
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[multicore_runner](multicore/multicore_runner) | Set up the second core to accept, and run, any function pointer pushed into its mailbox FIFO. Push in a few pieces of code and get answers back.
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### Pico Board
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@ -162,6 +160,7 @@ App|Description
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[mpu9250_spi](spi/mpu9250_spi) | Attach a MPU9250 accelerometer/gyoscope via SPI.
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[spi_dma](spi/spi_dma) | Use DMA to transfer data both to and from the SPI simultaneously. The SPI is configured for loopback.
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[spi_flash](spi/spi_flash) | Erase, program and read a serial flash device attached to one of the SPI controllers.
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[spi_master_slave](spi/spi_master_slave) | Demonstrate SPI communication as master and slave.
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### System
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@ -170,6 +169,7 @@ App|Description
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[hello_double_tap](system/hello_double_tap) | An LED blink with the `pico_bootsel_via_double_reset` library linked. This enters the USB bootloader when it detects the system being reset twice in quick succession, which is useful for boards with a reset button but no BOOTSEL button.
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[narrow_io_write](system/narrow_io_write) | Demonstrate the effects of 8-bit and 16-bit writes on a 32-bit IO register.
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[unique_board_id](system/unique_board_id) | Read the 64 bit unique ID from external flash, which serves as a unique identifier for the board.
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### Timer
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App|Description
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@ -2,5 +2,6 @@ if (NOT PICO_NO_HARDWARE)
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add_subdirectory(bme280_spi)
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add_subdirectory(mpu9250_spi)
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add_subdirectory(spi_dma)
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add_subdirectory(spi_master_slave)
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add_subdirectory(spi_flash)
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endif ()
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2
spi/spi_master_slave/CMakeLists.txt
Normal file
2
spi/spi_master_slave/CMakeLists.txt
Normal file
@ -0,0 +1,2 @@
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add_subdirectory(spi_master)
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add_subdirectory(spi_slave)
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140
spi/spi_master_slave/README.adoc
Normal file
140
spi/spi_master_slave/README.adoc
Normal file
@ -0,0 +1,140 @@
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= Communicating as master and slave via SPI
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This example code shows how to interface two RP2040 microcontrollers to each other using SPI.
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== Wiring information
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[frame="topbot",options="header"]
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|===
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| Function | Master (RP2040) | Slave (RP2040) | Master (Pico) | Slave (Pico)
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| MOSI | DO0 | DI0 | 25 | 21
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| SCLK | SCK0 | SCK0 | 24 | 24
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| GND | GND | GND | 23 | 23
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| CS | CS0 | CS0 | 22 | 22
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| MISO | DI0 | DO0 | 21 | 25
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|===
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[[spi_master_slave_wiring]]
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[pdfwidth=75%]
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.Wiring Diagram for SPI Master and Slave.
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image::spi_master_slave_bb.png[]
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At least one of the boards should be powered, and will share power to the other.
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If the master is not connected properly to a slave, the master will report reading all zeroes.
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If the slave is not connected properly to a master, it will initialize but never transmit nor receive, because it's waiting for clock signal from the master.
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== Outputs
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Both master and slave boards will give output to stdio.
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With master and slave properly connected, the master should output something like this:
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....
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SPI master example
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SPI master says: The following buffer will be written to MOSI endlessly:
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00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
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10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
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20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
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30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
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40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
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50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
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60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
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70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f
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80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f
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90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f
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a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af
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b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf
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c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf
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d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df
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e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef
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f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff
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SPI master says: read page 0 from the MISO line:
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ff fe fd fc fb fa f9 f8 f7 f6 f5 f4 f3 f2 f1 f0
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ef ee ed ec eb ea e9 e8 e7 e6 e5 e4 e3 e2 e1 e0
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df de dd dc db da d9 d8 d7 d6 d5 d4 d3 d2 d1 d0
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cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0
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bf be bd bc bb ba b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
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af ae ad ac ab aa a9 a8 a7 a6 a5 a4 a3 a2 a1 a0
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9f 9e 9d 9c 9b 9a 99 98 97 96 95 94 93 92 91 90
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8f 8e 8d 8c 8b 8a 89 88 87 86 85 84 83 82 81 80
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7f 7e 7d 7c 7b 7a 79 78 77 76 75 74 73 72 71 70
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6f 6e 6d 6c 6b 6a 69 68 67 66 65 64 63 62 61 60
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5f 5e 5d 5c 5b 5a 59 58 57 56 55 54 53 52 51 50
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4f 4e 4d 4c 4b 4a 49 48 47 46 45 44 43 42 41 40
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3f 3e 3d 3c 3b 3a 39 38 37 36 35 34 33 32 31 30
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2f 2e 2d 2c 2b 2a 29 28 27 26 25 24 23 22 21 20
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1f 1e 1d 1c 1b 1a 19 18 17 16 15 14 13 12 11 10
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0f 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00
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....
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The slave should output something like this:
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....
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SPI slave example
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SPI slave says: When reading from MOSI, the following buffer will be written to MISO:
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ff fe fd fc fb fa f9 f8 f7 f6 f5 f4 f3 f2 f1 f0
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ef ee ed ec eb ea e9 e8 e7 e6 e5 e4 e3 e2 e1 e0
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df de dd dc db da d9 d8 d7 d6 d5 d4 d3 d2 d1 d0
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cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0
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bf be bd bc bb ba b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
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af ae ad ac ab aa a9 a8 a7 a6 a5 a4 a3 a2 a1 a0
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9f 9e 9d 9c 9b 9a 99 98 97 96 95 94 93 92 91 90
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8f 8e 8d 8c 8b 8a 89 88 87 86 85 84 83 82 81 80
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7f 7e 7d 7c 7b 7a 79 78 77 76 75 74 73 72 71 70
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6f 6e 6d 6c 6b 6a 69 68 67 66 65 64 63 62 61 60
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5f 5e 5d 5c 5b 5a 59 58 57 56 55 54 53 52 51 50
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4f 4e 4d 4c 4b 4a 49 48 47 46 45 44 43 42 41 40
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3f 3e 3d 3c 3b 3a 39 38 37 36 35 34 33 32 31 30
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2f 2e 2d 2c 2b 2a 29 28 27 26 25 24 23 22 21 20
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1f 1e 1d 1c 1b 1a 19 18 17 16 15 14 13 12 11 10
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0f 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00
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SPI slave says: read page 0 from the MOSI line:
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00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
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10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
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20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
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30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
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40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
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50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
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60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
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70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f
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80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f
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90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f
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a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af
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b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf
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c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf
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d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df
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e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef
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f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff
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....
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If you look at the communication with a logic analyzer, you should see this:
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[[spi_master_slave_wiring]]
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[pdfwidth=75%]
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.Data capture as seen in Saleae Logic.
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image::spi_master_slave_logic.png[]
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== List of Files
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CMakeLists.txt:: CMake file to incorporate the example in to the examples build tree.
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spi_master/spi_master.c:: The example code for SPI master.
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spi_slave/spi_slave.c:: The example code for SPI slave.
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spi_master_slave_logic.png:: Communication as seen by logic analyzer.
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spi_master_slave.csv:: Communication as seen by logic analyzer, exported to CSV format.
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spi_master_slave.fzz:: Fritzing file.
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spi_master_slave_bb.png:: Breadboard wiring diagram.
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== Bill of Materials
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.A list of materials required for the example
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[[spi-master-slave-bom-table]]
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[cols=3]
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|===
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| *Item* | *Quantity* | Details
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| Breadboard | 1 | generic part
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| Raspberry Pi Pico | 2 | http://raspberrypi.org/
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| M/M Jumper wires | 8 | generic part
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|===
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12
spi/spi_master_slave/spi_master/CMakeLists.txt
Normal file
12
spi/spi_master_slave/spi_master/CMakeLists.txt
Normal file
@ -0,0 +1,12 @@
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add_executable(spi_master
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spi_master.c
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)
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# Pull in basic dependencies
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target_link_libraries(spi_master pico_stdlib hardware_spi)
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# create map/bin/hex file etc.
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pico_add_extra_outputs(spi_master)
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# add url via pico_set_program_url
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example_auto_set_url(spi_master)
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89
spi/spi_master_slave/spi_master/spi_master.c
Normal file
89
spi/spi_master_slave/spi_master/spi_master.c
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@ -0,0 +1,89 @@
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// Copyright (c) 2021 Michael Stoops. All rights reserved.
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// Portions copyright (c) 2021 Raspberry Pi (Trading) Ltd.
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//
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// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
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// following conditions are met:
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//
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// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
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// disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
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// following disclaimer in the documentation and/or other materials provided with the distribution.
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// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
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// products derived from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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// USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// SPDX-License-Identifier: BSD-3-Clause
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//
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// Example of an SPI bus master using the PL022 SPI interface
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#include <stdio.h>
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#include "pico/stdlib.h"
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#include "pico/binary_info.h"
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#include "hardware/spi.h"
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#define BUF_LEN 0x100
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void printbuf(uint8_t buf[], size_t len) {
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int i;
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for (i = 0; i < len; ++i) {
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if (i % 16 == 15)
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printf("%02x\n", buf[i]);
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else
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printf("%02x ", buf[i]);
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}
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// append trailing newline if there isn't one
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if (i % 16) {
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putchar('\n');
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}
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}
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int main() {
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// Enable UART so we can print
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stdio_init_all();
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#if !defined(spi_default) || !defined(PICO_DEFAULT_SPI_SCK_PIN) || !defined(PICO_DEFAULT_SPI_TX_PIN) || !defined(PICO_DEFAULT_SPI_RX_PIN) || !defined(PICO_DEFAULT_SPI_CSN_PIN)
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#warning spi/spi_master example requires a board with SPI pins
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puts("Default SPI pins were not defined");
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#else
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printf("SPI master example\n");
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// Enable SPI 0 at 1 MHz and connect to GPIOs
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spi_init(spi_default, 1000 * 1000);
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gpio_set_function(PICO_DEFAULT_SPI_RX_PIN, GPIO_FUNC_SPI);
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gpio_set_function(PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI);
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gpio_set_function(PICO_DEFAULT_SPI_TX_PIN, GPIO_FUNC_SPI);
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gpio_set_function(PICO_DEFAULT_SPI_CSN_PIN, GPIO_FUNC_SPI);
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// Make the SPI pins available to picotool
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bi_decl(bi_4pins_with_func(PICO_DEFAULT_SPI_RX_PIN, PICO_DEFAULT_SPI_TX_PIN, PICO_DEFAULT_SPI_SCK_PIN, PICO_DEFAULT_SPI_CSN_PIN, GPIO_FUNC_SPI));
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uint8_t out_buf[BUF_LEN], in_buf[BUF_LEN];
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// Initialize output buffer
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for (size_t i = 0; i < BUF_LEN; ++i) {
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out_buf[i] = i;
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}
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printf("SPI master says: The following buffer will be written to MOSI endlessly:\n");
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printbuf(out_buf, BUF_LEN);
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for (size_t i = 0; ; ++i) {
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// Write the output buffer to MOSI, and at the same time read from MISO.
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spi_write_read_blocking(spi_default, out_buf, in_buf, BUF_LEN);
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// Write to stdio whatever came in on the MISO line.
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printf("SPI master says: read page %d from the MISO line:\n", i);
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printbuf(in_buf, BUF_LEN);
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// Sleep for ten seconds so you get a chance to read the output.
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sleep_ms(10 * 1000);
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}
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#endif
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}
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5224
spi/spi_master_slave/spi_master_slave.csv
Normal file
5224
spi/spi_master_slave/spi_master_slave.csv
Normal file
File diff suppressed because it is too large
Load Diff
BIN
spi/spi_master_slave/spi_master_slave.fzz
Normal file
BIN
spi/spi_master_slave/spi_master_slave.fzz
Normal file
Binary file not shown.
BIN
spi/spi_master_slave/spi_master_slave_bb.png
Normal file
BIN
spi/spi_master_slave/spi_master_slave_bb.png
Normal file
Binary file not shown.
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After Width: | Height: | Size: 248 KiB |
BIN
spi/spi_master_slave/spi_master_slave_logic.png
Normal file
BIN
spi/spi_master_slave/spi_master_slave_logic.png
Normal file
Binary file not shown.
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After Width: | Height: | Size: 133 KiB |
12
spi/spi_master_slave/spi_slave/CMakeLists.txt
Normal file
12
spi/spi_master_slave/spi_slave/CMakeLists.txt
Normal file
@ -0,0 +1,12 @@
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add_executable(spi_slave
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spi_slave.c
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)
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# Pull in basic dependencies
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target_link_libraries(spi_slave pico_stdlib hardware_spi)
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# create map/bin/hex file etc.
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pico_add_extra_outputs(spi_slave)
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# add url via pico_set_program_url
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example_auto_set_url(spi_slave)
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90
spi/spi_master_slave/spi_slave/spi_slave.c
Normal file
90
spi/spi_master_slave/spi_slave/spi_slave.c
Normal file
@ -0,0 +1,90 @@
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// Copyright (c) 2021 Michael Stoops. All rights reserved.
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// Portions copyright (c) 2021 Raspberry Pi (Trading) Ltd.
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//
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// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
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// following conditions are met:
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//
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// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
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// disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
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// following disclaimer in the documentation and/or other materials provided with the distribution.
|
||||
// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
|
||||
// products derived from this software without specific prior written permission.
|
||||
//
|
||||
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
|
||||
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||||
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
||||
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||||
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
||||
// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
|
||||
// USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
//
|
||||
// SPDX-License-Identifier: BSD-3-Clause
|
||||
//
|
||||
// Example of an SPI bus slave using the PL022 SPI interface
|
||||
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include "pico/stdlib.h"
|
||||
#include "pico/binary_info.h"
|
||||
#include "hardware/spi.h"
|
||||
|
||||
#define BUF_LEN 0x100
|
||||
|
||||
void printbuf(uint8_t buf[], size_t len) {
|
||||
int i;
|
||||
for (i = 0; i < len; ++i) {
|
||||
if (i % 16 == 15)
|
||||
printf("%02x\n", buf[i]);
|
||||
else
|
||||
printf("%02x ", buf[i]);
|
||||
}
|
||||
|
||||
// append trailing newline if there isn't one
|
||||
if (i % 16) {
|
||||
putchar('\n');
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
int main() {
|
||||
// Enable UART so we can print
|
||||
stdio_init_all();
|
||||
#if !defined(spi_default) || !defined(PICO_DEFAULT_SPI_SCK_PIN) || !defined(PICO_DEFAULT_SPI_TX_PIN) || !defined(PICO_DEFAULT_SPI_RX_PIN) || !defined(PICO_DEFAULT_SPI_CSN_PIN)
|
||||
#warning spi/spi_slave example requires a board with SPI pins
|
||||
puts("Default SPI pins were not defined");
|
||||
#else
|
||||
|
||||
printf("SPI slave example\n");
|
||||
|
||||
// Enable SPI 0 at 1 MHz and connect to GPIOs
|
||||
spi_init(spi_default, 1000 * 1000);
|
||||
spi_set_slave(spi_default, true);
|
||||
gpio_set_function(PICO_DEFAULT_SPI_RX_PIN, GPIO_FUNC_SPI);
|
||||
gpio_set_function(PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI);
|
||||
gpio_set_function(PICO_DEFAULT_SPI_TX_PIN, GPIO_FUNC_SPI);
|
||||
gpio_set_function(PICO_DEFAULT_SPI_CSN_PIN, GPIO_FUNC_SPI);
|
||||
// Make the SPI pins available to picotool
|
||||
bi_decl(bi_4pins_with_func(PICO_DEFAULT_SPI_RX_PIN, PICO_DEFAULT_SPI_TX_PIN, PICO_DEFAULT_SPI_SCK_PIN, PICO_DEFAULT_SPI_CSN_PIN, GPIO_FUNC_SPI));
|
||||
|
||||
uint8_t out_buf[BUF_LEN], in_buf[BUF_LEN];
|
||||
|
||||
// Initialize output buffer
|
||||
for (size_t i = 0; i < BUF_LEN; ++i) {
|
||||
// bit-inverted from i. The values should be: {0xff, 0xfe, 0xfd...}
|
||||
out_buf[i] = ~i;
|
||||
}
|
||||
|
||||
printf("SPI slave says: When reading from MOSI, the following buffer will be written to MISO:\n");
|
||||
printbuf(out_buf, BUF_LEN);
|
||||
|
||||
for (size_t i = 0; ; ++i) {
|
||||
// Write the output buffer to MISO, and at the same time read from MOSI.
|
||||
spi_write_read_blocking(spi_default, out_buf, in_buf, BUF_LEN);
|
||||
|
||||
// Write to stdio whatever came in on the MOSI line.
|
||||
printf("SPI slave says: read page %d from the MOSI line:\n", i);
|
||||
printbuf(in_buf, BUF_LEN);
|
||||
}
|
||||
#endif
|
||||
}
|
||||
Reference in New Issue
Block a user