Added spi/spi_master_slave. (#101)

Co-authored-by: Michael Stoops <spam@michaelstoops.com>
2022-05-16 12:22:24 -07:00
parent 1a2a85ca6e
commit 2147301e11
12 changed files with 5574 additions and 4 deletions
--- a/spi/spi_master_slave/spi_master/spi_master.c
+++ b/spi/spi_master_slave/spi_master/spi_master.c
@@ -0,0 +1,89 @@
+// Copyright (c) 2021 Michael Stoops. All rights reserved.
+// Portions copyright (c) 2021 Raspberry Pi (Trading) Ltd.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the 
+// following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
+//    disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
+//    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 master using the PL022 SPI interface
+
+#include <stdio.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_master example requires a board with SPI pins
+    puts("Default SPI pins were not defined");
+#else
+
+    printf("SPI master example\n");
+
+    // Enable SPI 0 at 1 MHz and connect to GPIOs
+    spi_init(spi_default, 1000 * 1000);
+    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) {
+        out_buf[i] = i;
+    }
+
+    printf("SPI master says: The following buffer will be written to MOSI endlessly:\n");
+    printbuf(out_buf, BUF_LEN);
+
+    for (size_t i = 0; ; ++i) {
+        // Write the output buffer to MOSI, and at the same time read from MISO.
+        spi_write_read_blocking(spi_default, out_buf, in_buf, BUF_LEN);
+
+        // Write to stdio whatever came in on the MISO line.
+        printf("SPI master says: read page %d from the MISO line:\n", i);
+        printbuf(in_buf, BUF_LEN);
+
+        // Sleep for ten seconds so you get a chance to read the output.
+        sleep_ms(10 * 1000);
+    }
+#endif
+}