Initial Release

pio/differential_manchester/differential_manchester.c

@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+
+#include "pico/stdlib.h"
+#include "hardware/pio.h"
+#include "differential_manchester.pio.h"
+
+// Differential serial transmit/receive example
+// Need to connect a wire from GPIO2 -> GPIO3
+
+const uint pin_tx = 2;
+const uint pin_rx = 3;
+
+int main() {
+    stdio_init_all();
+
+    PIO pio = pio0;
+    uint sm_tx = 0;
+    uint sm_rx = 1;
+
+    uint offset_tx = pio_add_program(pio, &differential_manchester_tx_program);
+    uint offset_rx = pio_add_program(pio, &differential_manchester_rx_program);
+    printf("Transmit program loaded at %d\n", offset_tx);
+    printf("Receive program loaded at %d\n", offset_rx);
+
+    // Configure state machines, set bit rate at 5 Mbps
+    differential_manchester_tx_program_init(pio, sm_tx, offset_tx, pin_tx, 125.f / (16 * 5));
+    differential_manchester_rx_program_init(pio, sm_rx, offset_rx, pin_rx, 125.f / (16 * 5));
+
+    pio_sm_set_enabled(pio, sm_tx, false);
+    pio_sm_put_blocking(pio, sm_tx, 0);
+    pio_sm_put_blocking(pio, sm_tx, 0x0ff0a55a);
+    pio_sm_put_blocking(pio, sm_tx, 0x12345678);
+    pio_sm_set_enabled(pio, sm_tx, true);
+
+    for (int i = 0; i < 3; ++i)
+        printf("%08x\n", pio_sm_get_blocking(pio, sm_rx));
+}