Diff: main.cpp

Revision:

0:300d8042b9fe

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Aug 07 16:20:58 2019 +0000
@@ -0,0 +1,73 @@
+// Basic I2C scanner. Runs at startup and when it receives a "s" character via serial. Prints out the address of any devices found on the bus.
+
+#include "mbed.h"
+#include <string>
+
+bool i2cScan = true;
+bool debugEnabled = true;
+
+I2C i2c(PB_9, PB_8);        // sda, scl
+//I2C i2c(D4, D5);        // sda, scl
+Serial pc(USBTX, USBRX, 115200); // tx, rx, baud
+
+// Begin serial port functions/variables
+Timer serialTimer;
+
+char cSerialRx; // Raw character from serialRx
+string sSerialRx; // Serial received string
+
+void serialRx_interrupt()
+{
+    // If time since last character received is too long, reset the received characters string and unlock the i2c bus
+    if ((uint32_t)serialTimer.read_ms() > 5) {
+        sSerialRx.clear();
+    }
+
+    cSerialRx=pc.getc(); // Get individual characters from serial
+    sSerialRx+=cSerialRx; // and string them together
+
+    switch (cSerialRx) {
+        case 's': // Trigger a I2C scan
+            i2cScan = true;
+
+            sSerialRx.clear(); // clear serial buffer
+            break;
+
+
+        case 'q':
+            if (debugEnabled) {
+                pc.printf("Restarting...\n\r");
+            }
+            NVIC_SystemReset();
+
+        default:
+            // No action by default; wait for next character
+            //break;
+    }
+    serialTimer.reset(); // Reset timer
+}
+// End serial port functions/variables
+
+int main()
+{
+    int error = 0;
+
+    pc.attach(&serialRx_interrupt, Serial::RxIrq); // Create serial rx interrupt to process incoming commands
+    serialTimer.start(); // Serial timer to keep track of time between characters
+
+    i2c.frequency(100000);
+
+    while (true) {
+        if (i2cScan) {
+            i2cScan = false;
+            for(int i = 0; i < 128 ; i++) {
+                i2c.start();
+                error = i2c.write(i << 1);
+                i2c.stop();
+                if (error == 1) {
+                    printf("0x%X\r\n", i); //Return 7-bit address
+                }
+            }
+        }
+    }
+}
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