hello

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
GeofferyOmlette
Date:
Mon Jul 14 15:13:45 2014 +0000
Commit message:
hello

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r f2ba1ee4ee06 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jul 14 15:13:45 2014 +0000
@@ -0,0 +1,130 @@
+#include "mbed.h"
+
+#include <vector>
+ 
+Serial       pc(USBTX, USBRX); // tx, rx
+Serial       c2c(p13, p14);    // tx, rx
+DigitalInOut   nREQ(p15);
+DigitalInOut   nRDY(p16);
+
+
+// Fletcher checksum calculation, not optimised
+static uint16_t checkSum(uint8_t length_byte, uint8_t* buf){
+    // length is treated as 16-bit for checksum calculation
+    uint16_t sum1 = length_byte % 255;
+    uint16_t sum2 = sum1;
+ 
+    for (int i = 0; i < length_byte; i++) {
+        sum1 = (sum1 + buf[i]) % 255;
+        sum2 = (sum2 + sum1) % 255;
+    }
+ 
+    return ((sum2 << 8) | sum1);
+}
+
+void sendTestPacket(){
+    pc.printf("\n\rTX: wait for nRDY... ");
+    
+    nREQ = 0;
+    nREQ.mode(PinMode(OpenDrain));
+    nREQ.output();
+    
+    nRDY = 1;
+    nRDY.input();
+    
+    // wait for nRDY
+    while(nRDY == 1)
+        wait(0.1);
+
+    pc.printf("\n\rgot nRDY\n\r");
+    const uint8_t len = 0;
+    
+    c2c.putc(len);
+    while(!c2c.writeable())
+        ;
+    pc.printf("wrote len=%d\n\r", len);
+    uint8_t data[len==0? 256 : len];
+    for(int i = 0; i < (len==0? 256 : len); i++){
+        data[i] = uint8_t((i + 31) & 0xff);
+        c2c.putc(data[i]);
+        pc.printf(".");
+        while(!c2c.writeable())
+            ;
+    }
+    pc.printf("\n\rwrote data\n\r", len);
+    uint16_t csum = checkSum(len, data);
+    c2c.putc(uint8_t(csum & 0xff));
+    while(!c2c.writeable())
+        ;
+    c2c.putc(uint8_t((csum >> 8) & 0xff));
+    pc.printf("\n\rwrote checksum\n\r", len);
+}
+
+void receiveTestPacket(){
+    pc.printf("RX: wait for nREQ...");
+    
+    nREQ = 0;
+    nRDY = 0;
+    nREQ.mode(PinMode(OpenDrain | PullUp));
+    nRDY.mode(PinMode(OpenDrain | PullUp));
+    nREQ.output();
+    nRDY.output();    
+    
+//    nREQ.input();
+//    nRDY = 1;
+//    nRDY.mode(PinMode(OpenDrain));
+    
+    while(nREQ == 0)
+        wait(0.1);
+        
+    pc.printf("\n\rgot REQ\n\r");
+    nRDY = 1;
+    int len = c2c.getc();
+    std::vector<uint8_t> msg;
+    for(int i = 0; i < len; i++)
+        msg.push_back(c2c.getc());
+    
+    uint16_t csum = 0;
+    for(int i =0; i < 2; i++)
+        csum |= (uint16_t(c2c.getc()) << (i*8));
+    
+    
+    pc.printf("len=%d\n\r", len);
+    for(int i = 0; i < len; i++)
+        pc.printf("0x%x ", msg[i]);
+    pc.printf("\n\rcsum : 0x%x\n\r", csum);
+    
+    uint16_t check_checksum = checkSum(len, &msg[0]);
+    pc.printf("check: 0x%x\n\r", check_checksum);
+    
+    nRDY = 0;
+}
+
+int main() {
+    pc.printf("\n\r--------\n\rc2c UART Test\n\r");
+    
+    c2c.baud(38400);
+    
+//    while(1) {
+//        if(c2c.readable()) {
+//            pc.putc(c2c.getc());
+//        }
+//    }
+    
+    if(c2c.readable())
+        pc.printf("Leftover characters:");
+    while(c2c.readable())
+        pc.printf("0x%x ", int(c2c.getc()));
+    pc.printf("\n\r");
+    
+    
+    // receive rx_count things
+    int rx_count = 1;
+    while(rx_count > 0){
+        receiveTestPacket();
+    }
+    
+//    sendTestPacket();
+//    
+    pc.printf("\n\r--- complete ---\n\r");
+}
\ No newline at end of file
diff -r 000000000000 -r f2ba1ee4ee06 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Mon Jul 14 15:13:45 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/04dd9b1680ae
\ No newline at end of file