Diff: main.cpp

Revision:

0:5ca8a4347f67

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Aug 08 14:08:44 2014 +0000
@@ -0,0 +1,79 @@
+#include "USBHostCam.h"
+RawSerial pc(USBTX, USBRX);
+
+uint8_t image_buf[1024*64];
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+#define LED_OFF 1
+#define LED_ON  0
+
+int main() {
+    pc.baud(9600);
+    led1 = led2 = LED_OFF;
+
+    // Logitech C270
+    USBHostCam* cam = new USBHostCam(_800x448);
+    if (!cam->connect()) {
+        error("WebCam not found.\n");
+    }
+
+    int pos = 0; 
+    int size = 0;
+    Timer t;
+    for(int seq = 0;;) {
+        int c = -1;
+        if (pc.readable()) {
+            c = pc.getc();
+        }    
+        switch(seq) {
+            case 0:
+                pc.printf("\nReady, please download JPEG using XMODEM/Checksum.\n");
+                t.start();
+                seq++;
+                break;
+            case 1:
+                if (c == 0x15) { // NAK
+                    size = cam->readJPEG(image_buf, sizeof(image_buf));
+                    pos = 0;
+                    seq++;
+                }
+                break;
+            case 2:
+                if (pos >= size) {
+                    pc.putc(0x04); // EOT
+                } else {
+                    pc.putc(0x01); // SOH
+                    uint8_t block = pos/128 + 1;
+                    pc.putc(block);
+                    pc.putc(block ^ 0xff);
+                    uint8_t checksum = 0x00;
+                    for(int i = 0; i < 128; i++) {
+                        uint8_t c = image_buf[pos + i];
+                        checksum += c;
+                        pc.putc(c);
+                    }
+                    pc.putc(checksum);
+                }
+                seq++;
+                t.reset();
+                led2 = !led2;
+                break;
+            case 3:
+                if (c == 0x06) { // ACK
+                    if (pos >= size) {
+                        seq = 0;
+                    } else {
+                        pos += 128;
+                        seq--;
+                    }
+                }
+                break;
+        }
+        if (t.read_ms() > 15*1000) { // timeout
+            t.reset();
+            seq = 0;
+        }
+        cam->poll();
+    }
+}
+