Diff: I2CDriverTest01.h

Revision:

3:967dde37e712

Child:

4:eafa7efcd771

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2CDriverTest01.h	Fri Apr 19 21:33:29 2013 +0000
@@ -0,0 +1,68 @@
+#include "mbed.h"
+#include "rtos.h"
+#include "I2CMasterRtos.h"
+#include "stdint.h"
+
+volatile int disco=0;
+volatile osThreadId i2cDrvThrdID;
+
+void highPrioCallBck(void const *args)
+{
+    osSignalSet(i2cDrvThrdID, 1<<5);
+}
+
+void highPrioThreadFun(void const *args)
+{
+    i2cDrvThrdID = Thread::gettid();
+    I2CMasterRtos i2c(p28, p27);
+    i2c.frequency(400000);
+    const uint32_t adr = 0x70<<1;
+
+    // trigger on srf08 ranging
+    const char regNcmd[2]= {0x00,0x51};
+    i2c.write(adr, regNcmd, 2);
+
+    while(true) {
+        Thread::signal_wait(1<<5,osWaitForever);
+        // read back srf08 echo times (1+16 words)
+        const char reg= 0x02;
+        char result[64];
+        uint32_t t1=us_ticker_read();
+        i2c.read(adr, reg, result, 25, 1);
+
+        uint32_t dt=us_ticker_read()-t1;
+        uint16_t tm=((static_cast<uint16_t>(result[0])<<8)|static_cast<uint16_t>(result[1]));
+        
+        if(--disco>0) printf("tm=%4dus dt=%4dus\n",tm,dt);
+    }
+}
+
+int doit()
+{
+    Thread highPrioThread(highPrioThreadFun,0,osPriorityAboveNormal);
+    RtosTimer highPrioTicker(highPrioCallBck, osTimerPeriodic, (void *)0);
+
+    Thread::wait(100);
+    highPrioTicker.start(1);
+
+    uint32_t cnt=0;
+    while (++cnt<5) {
+        const uint32_t dt=1e6;
+        uint32_t tStart = us_ticker_read();
+        uint32_t tLast = tStart;
+        uint32_t tAct = tStart;
+        uint32_t tMe=0;
+        do {
+            tAct=us_ticker_read();
+            if(tAct>tLast) {
+                if(tAct==tLast+1)++tMe;
+            }
+            tLast=tAct;
+        } while(tAct-tStart<dt);
+        printf("dc=%5.2f \n", 100.0*(float)tMe/dt);
+        disco=10;
+        while(disco>0);
+        Thread::wait(1000);
+    }
+    return 0;
+}
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