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-rw-r--r--examples/test-spi-roundtrip.cpp197
1 files changed, 197 insertions, 0 deletions
diff --git a/examples/test-spi-roundtrip.cpp b/examples/test-spi-roundtrip.cpp
new file mode 100644
index 0000000..257303b
--- /dev/null
+++ b/examples/test-spi-roundtrip.cpp
@@ -0,0 +1,197 @@
+/*
+ * Polling SPI loopback test.
+ *
+ * Bob is nowhere to be found, so Alice decides to talk to herself.
+ *
+ * Instructions: Connect SPI2 (Alice) to herself (i.e., MISO to MOSI).
+ * Connect to Alice via Serial2 at 115200 baud. Press any key to start.
+ *
+ * Alice will talk to herself for a little while. The sketch will
+ * report if Alice can't hear anything she says. She'll then start
+ * talking forever at various frequencies, bit orders, and modes. Use
+ * an oscilloscope to make sure she's not trying to lie about any of
+ * those things.
+ *
+ * This file is released into the public domain.
+ *
+ * Author: Marti Bolivar <mbolivar@leaflabs.com>
+ */
+
+#include "wirish.h"
+
+HardwareSPI alice(2);
+
+#define NFREQS 8
+const SPIFrequency spi_freqs[] = {
+ SPI_140_625KHZ,
+ SPI_281_250KHZ,
+ SPI_562_500KHZ,
+ SPI_1_125MHZ,
+ SPI_2_25MHZ,
+ SPI_4_5MHZ,
+ SPI_9MHZ,
+ SPI_18MHZ,
+};
+
+#define TEST_BUF_SIZE 10
+uint8 test_buf[TEST_BUF_SIZE] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+void bad_assert(const char* file, int line, const char* exp) {
+ Serial2.println();
+ Serial2.print("ERROR: FAILED ASSERT(");
+ Serial2.print(exp);
+ Serial2.print("): ");
+ Serial2.print(file);
+ Serial2.print(": ");
+ Serial2.println(line);
+ throb();
+}
+
+#undef ASSERT
+#define ASSERT(exp) \
+ if (exp) { \
+ } else { \
+ bad_assert(__FILE__, __LINE__, #exp); \
+ }
+
+void haveConversation(uint32 bitOrder);
+void soliloquies(uint32 bitOrder);
+
+void setup() {
+ pinMode(BOARD_LED_PIN, OUTPUT);
+ Serial2.begin(115200);
+ Serial2.println();
+ Serial2.print("** SPI test ready. Press any key to start.");
+ while (!Serial2.available())
+ ;
+ Serial2.read();
+}
+
+void loop() {
+ Serial2.println("** Having a conversation, MSB first");
+ haveConversation(MSBFIRST);
+
+ Serial2.println("** Having a conversation, LSB first");
+ haveConversation(LSBFIRST);
+
+ Serial2.println();
+ Serial2.println("*** All done! It looks like everything worked.");
+ Serial2.println();
+
+ Serial2.println("** Alice will now wax eloquent in various styles. "
+ "Press any key for the next configuration.");
+ soliloquies(MSBFIRST);
+ soliloquies(LSBFIRST);
+
+ while (true)
+ ;
+}
+
+void printFrequencyString(SPIFrequency frequency);
+void chat(SPIFrequency frequency, uint32 bitOrder, uint32 mode);
+
+void haveConversation(uint32 bitOrder) {
+ for (int f = 0; f < NFREQS; f++) {
+ for (int mode = 0; mode < 4; mode++) {
+ chat(spi_freqs[f], bitOrder, mode);
+ delay(10);
+ }
+ }
+}
+
+void chat(SPIFrequency frequency, uint32 bitOrder, uint32 mode) {
+ Serial2.print("Having a chat.\tFrequency: ");
+ printFrequencyString(frequency);
+ Serial2.print(",\tbitOrder: ");
+ Serial2.print(bitOrder == MSBFIRST ? "MSB" : "LSB");
+ Serial2.print(",\tmode: ");
+ Serial2.print(mode);
+ Serial2.print(".");
+
+ Serial2.print(" [1] ");
+ alice.begin(frequency, bitOrder, mode);
+
+ Serial2.print(" [2] ");
+ uint32 txed = 0;
+ while (txed < TEST_BUF_SIZE) {
+ ASSERT(alice.transfer(test_buf[txed]) == test_buf[txed]);
+ txed++;
+ }
+
+ Serial2.print(" [3] ");
+ alice.end();
+
+ Serial2.println(" ok.");
+}
+
+void soliloquy(SPIFrequency freq, uint32 bitOrder, uint32 mode);
+
+void soliloquies(uint32 bitOrder) {
+ for (int f = 0; f < NFREQS; f++) {
+ for (int mode = 0; mode < 4; mode++) {
+ soliloquy(spi_freqs[f], bitOrder, mode);
+ }
+ }
+}
+
+void soliloquy(SPIFrequency frequency, uint32 bitOrder, uint32 mode) {
+ const uint8 repeat = 0xAE;
+ Serial2.print("Alice is giving a soliloquy (repeating 0x");
+ Serial2.print(repeat, HEX);
+ Serial2.print("). Frequency: ");
+ printFrequencyString(frequency);
+ Serial2.print(", bitOrder: ");
+ Serial2.print(bitOrder == MSBFIRST ? "big-endian" : "little-endian");
+ Serial2.print(", SPI mode: ");
+ Serial2.println(mode);
+
+ alice.begin(frequency, bitOrder, mode);
+ while (!Serial2.available()) {
+ alice.write(repeat);
+ delayMicroseconds(200);
+ }
+ Serial2.read();
+}
+
+void printFrequencyString(SPIFrequency frequency) {
+ switch (frequency) {
+ case SPI_18MHZ:
+ Serial2.print("18 MHz");
+ break;
+ case SPI_9MHZ:
+ Serial2.print("9 MHz");
+ break;
+ case SPI_4_5MHZ:
+ Serial2.print("4.5 MHz");
+ break;
+ case SPI_2_25MHZ:
+ Serial2.print("2.25 MHZ");
+ break;
+ case SPI_1_125MHZ:
+ Serial2.print("1.125 MHz");
+ break;
+ case SPI_562_500KHZ:
+ Serial2.print("562.500 KHz");
+ break;
+ case SPI_281_250KHZ:
+ Serial2.print("281.250 KHz");
+ break;
+ case SPI_140_625KHZ:
+ Serial2.print("140.625 KHz");
+ break;
+ }
+}
+
+// Force init to be called *first*, i.e. before static object allocation.
+// Otherwise, statically allocated objects that need libmaple may fail.
+__attribute__((constructor)) void premain() {
+ init();
+}
+
+int main(void) {
+ setup();
+ while (true) {
+ loop();
+ }
+ return 0;
+}