Add examples/mini-exti-test.cpp.

Nonportable (Maple Mini only) test of external interrupt
functionality.  When wired properly, this triggers various EXTI lines
simultaneously, keeping track of the number of times each handler is
invoked.

1 files changed, 251 insertions, 0 deletions

diff --git a/examples/mini-exti-test.cpp b/examples/mini-exti-test.cpp
new file mode 100644
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+++ b/examples/mini-exti-test.cpp
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+/*
+ * EXTI test (Maple Mini only).
+ *
+ * Setup: For i from 1 to N_EXTI (see below), connect exti_i_pin to
+ * src_i_pin.  Connect via SerialUSB and press a key to perform a test
+ * run.  In the printed results For each EXTI within a test run, the
+ * number triggered should match the number handled.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "wirish.h"
+
+// test routines
+void run_exti_test(void);
+void print_test_results(void);
+
+// -- State -------------------------------------------------------------------
+
+// Test using EXTI lines 0 -- (N_EXTI - 1).
+#define N_EXTI 6
+
+// src_pins[i] determines the line level for EXTI i.  these *must* be
+// in GPIOA.  if you want to change them, make sure they don't
+// conflict with exti_pins[].
+//
+//     src_pins[0] = D5  = PA6
+//     src_pins[1] = D4  = PA7
+//     src_pins[2] = D27 = PA8
+//     src_pins[3] = D26 = PA9
+//     src_pins[4] = D25 = PA10
+//     src_pins[5] = D22 = PA13
+#define SRC0 5
+#define SRC0_BIT BIT(6)
+#define SRC1 4
+#define SRC1_BIT BIT(7)
+#define SRC2 27
+#define SRC2_BIT BIT(8)
+#define SRC3 26
+#define SRC3_BIT BIT(9)
+#define SRC4 25
+#define SRC4_BIT BIT(10)
+#define SRC5 22
+#define SRC5_BIT BIT(13)
+// Setting a bit in GPIOA_SRC_MSK means that the given src pin will
+// actually trigger interrupts.  Useful for experimenting.
+#define GPIOA_SRC_MSK \
+    (SRC0_BIT | SRC1_BIT | SRC2_BIT | SRC3_BIT | SRC4_BIT | SRC5_BIT)
+const int src_pins[N_EXTI] = {
+    SRC0,
+    SRC1,
+    SRC2,
+    SRC3,
+    SRC4,
+    SRC5,
+};
+const int src_gpioa_msks[N_EXTI] = {
+    SRC0_BIT,
+    SRC1_BIT,
+    SRC2_BIT,
+    SRC3_BIT,
+    SRC4_BIT,
+    SRC5_BIT,
+};
+
+// exti_pins[i] <-> EXTI line i.  make sure these don't conflict with
+// src_pins.
+const int exti_pins[N_EXTI] = {
+    D3,      // PB0
+    D10,     // PA1
+    D2,      // PB2
+    D19,     // PB3
+    D7,      // PA4
+    D6,      // PA5
+};
+
+// EXTI handlers
+void exti_0_handler(void);
+void exti_1_handler(void);
+void exti_2_handler(void);
+void exti_3_handler(void);
+void exti_4_handler(void);
+void exti_5_handler(void);
+voidFuncPtr exti_handlers[N_EXTI] = {
+    exti_0_handler,
+    exti_1_handler,
+    exti_2_handler,
+    exti_3_handler,
+    exti_4_handler,
+    exti_5_handler,
+};
+
+// index i = number of times we've triggered EXTI line n
+static uint32 n_triggered[N_EXTI];
+
+// index i = number of times we've handled EXTI line n
+volatile static uint32 n_handled[N_EXTI];
+
+// -- setup() -----------------------------------------------------------------
+
+void setup(void) {
+    // Set up pin modes and get line levels stable
+    for (int i = 0; i < N_EXTI; i++) {
+        pinMode(src_pins[i], OUTPUT);
+        digitalWrite(src_pins[i], LOW);
+        pinMode(exti_pins[i], INPUT);
+    }
+
+    // Delay to ensure src_pins are all LOW before proceeding
+    delay(1);
+
+    // Attach interrupts
+    for (int i = 0; i < N_EXTI; i++) {
+        attachInterrupt(exti_pins[i], exti_handlers[i], RISING);
+    }
+}
+
+// -- loop() ------------------------------------------------------------------
+
+void loop(void) {
+    // Wait for user to send a byte before starting
+    while (!SerialUSB.available())
+        ;
+    while (SerialUSB.available()) {
+        SerialUSB.read();
+    }
+
+    // Run the test, print the results
+    run_exti_test();
+    print_test_results();
+
+    // Clear out the triggered/handled state
+    for (int i = 0; i < N_EXTI; i++) {
+        n_triggered[i] = 0;
+        n_handled[i] = 0;
+    }
+
+    SerialUSB.println();
+    SerialUSB.println();
+    SerialUSB.println();
+}
+
+// -- Test routines -----------------------------------------------------------
+
+#define N_RUNS 100
+void run_exti_test(void) {
+    for (int run = 0; run < N_RUNS; run++) {
+        // Trigger EXTIs simultaneously
+        GPIOA_BASE->BSRR = GPIOA_SRC_MSK;
+
+        // Reset line levels
+        GPIOA_BASE->BSRR = GPIOA_SRC_MSK << 16;
+
+        // Update number of times triggered
+        for (int i = 0; i < N_EXTI; i++) {
+            if (GPIOA_SRC_MSK & src_gpioa_msks[i]) {
+                n_triggered[i]++;
+            }
+        }
+    }
+}
+
+// string handling boilerplate
+void resetl(void);
+void appendl(const char str[]);
+void appendl(uint32 n);
+void printl(void);
+
+void print_test_results(void) {
+    SerialUSB.println("Results:");
+
+    resetl();
+    appendl("EXTI");
+    appendl("# Triggered");
+    appendl("# Handled");
+    printl();
+    resetl();
+
+    for (uint32 i = 0; i < N_EXTI; i++) {
+        appendl(i);
+        appendl(n_triggered[i]);
+        appendl(n_handled[i]);
+        printl();
+        resetl();
+    }
+}
+
+// -- EXTI handlers -----------------------------------------------------------
+
+void exti_0_handler(void) {
+    n_handled[0]++;
+}
+
+void exti_1_handler(void) {
+    n_handled[1]++;
+}
+
+void exti_2_handler(void) {
+    n_handled[2]++;
+}
+
+void exti_3_handler(void) {
+    n_handled[3]++;
+}
+
+void exti_4_handler(void) {
+    n_handled[4]++;
+}
+
+void exti_5_handler(void) {
+    n_handled[5]++;
+}
+
+// -- String handling ---------------------------------------------------------
+
+#define C_SIZ 20
+#define LIN_SIZ 80
+char l[LIN_SIZ + 1];
+char tmp[C_SIZ + 1];
+
+void resetl(void) {
+    l[0] = '\0';
+}
+
+void appendl(const char str[]) {
+    snprintf(tmp, C_SIZ, "%-*s", C_SIZ, str);
+    strncat(l, tmp, LIN_SIZ - strlen(tmp));
+}
+
+void appendl(uint32 n) {
+    snprintf(tmp, C_SIZ, "%-*u", C_SIZ, n);
+    strncat(l, tmp, LIN_SIZ - strlen(tmp));
+}
+
+void printl(void) {
+    SerialUSB.println(l);
+}
+
+// -- init()/main() -----------------------------------------------------------
+
+__attribute__((constructor)) void premain() { init(); }
+
+int main(void) {
+    setup();
+
+    while (true)
+        loop();
+
+    return 0;
+}