Ian Hua / I2cRtosDriver

I2CRTOS Driver by Helmut Schmücker. Removed included mbed-rtos library to prevent multiple definition. Make sure to include mbed-rtos library in your program!

Fork of I2cRtosDriver by Helmut Schmücker

I2CDriverTest01.h@16:2c6432b37cce, 2014-05-17 (annotated)

Committer:
pHysiX
Date:
Sat May 17 11:56:46 2014 +0000
Revision:
16:2c6432b37cce
Parent:
14:352609d395c1 
Modified to make 400kHz default

Who changed what in which revision?

UserRevisionLine numberNew contents of line
humlet 14:352609d395c1 1 // A high prio thread reads at a rate of 1kHz from a SRF08 ultrasonic ranger
humlet 14:352609d395c1 2 // data packets of different size, whereas the lower prio main thread measures the CPU time left.
humlet 14:352609d395c1 3
humlet 3:967dde37e712 4 #include "mbed.h"
humlet 3:967dde37e712 5 #include "rtos.h"
humlet 3:967dde37e712 6 #include "I2CMasterRtos.h"
humlet 3:967dde37e712 7 #include "stdint.h"
humlet 3:967dde37e712 8
humlet 4:eafa7efcd771 9 volatile int g_disco=0;
humlet 14:352609d395c1 10 volatile int g_len=2;
humlet 4:eafa7efcd771 11 volatile int g_freq=100000;
humlet 3:967dde37e712 12
humlet 14:352609d395c1 13 I2CMasterRtos i2c(p28, p27);
humlet 14:352609d395c1 14 const uint32_t adr = 0x70<<1;
humlet 8:5be85bd4c5ba 15
humlet 3:967dde37e712 16 void highPrioCallBck(void const *args)
humlet 3:967dde37e712 17 {
humlet 14:352609d395c1 18 i2c.frequency(g_freq);
humlet 14:352609d395c1 19 // read back srf08 echo times (1+16 words)
humlet 14:352609d395c1 20 const char reg= 0x02;
humlet 14:352609d395c1 21 char result[64];
humlet 14:352609d395c1 22 uint32_t t1=us_ticker_read();
humlet 14:352609d395c1 23 i2c.read(adr, reg, result, g_len);
humlet 14:352609d395c1 24 uint32_t dt=us_ticker_read()-t1;
humlet 14:352609d395c1 25 uint16_t dst=((static_cast<uint16_t>(result[0])<<8)|static_cast<uint16_t>(result[1]));
humlet 14:352609d395c1 26 if(--g_disco>0) printf("dst=%4dcm dt=%4dus\n",dst,dt);
humlet 3:967dde37e712 27 }
humlet 3:967dde37e712 28
humlet 3:967dde37e712 29 int doit()
humlet 3:967dde37e712 30 {
humlet 3:967dde37e712 31 RtosTimer highPrioTicker(highPrioCallBck, osTimerPeriodic, (void *)0);
humlet 3:967dde37e712 32
humlet 14:352609d395c1 33 Thread::wait(500);
humlet 14:352609d395c1 34 // trigger srf08 ranging
humlet 14:352609d395c1 35 const char regNcmd[2]= {0x00,0x54};
humlet 14:352609d395c1 36 i2c.write(adr, regNcmd, 2);
humlet 14:352609d395c1 37 osDelay(200);
humlet 14:352609d395c1 38
humlet 3:967dde37e712 39 highPrioTicker.start(1);
humlet 3:967dde37e712 40
humlet 6:5b98c902a659 41 #if defined(TARGET_LPC1768)
humlet 4:eafa7efcd771 42 const int nTest=7;
humlet 6:5b98c902a659 43 const int freq[nTest]= {1e5, 1e5, 1e5, 4e5, 4e5, 4e5, 4e5};
humlet 6:5b98c902a659 44 const int len[nTest]= {1, 4, 6, 1, 6, 12, 25};
humlet 6:5b98c902a659 45 #elif defined(TARGET_LPC11U24)
humlet 6:5b98c902a659 46 const int nTest=5;
humlet 6:5b98c902a659 47 const int freq[nTest]= {1e5, 1e5, 4e5, 4e5, 4e5 };
humlet 14:352609d395c1 48 const int len[nTest]= {1, 6, 1, 6, 23};
humlet 6:5b98c902a659 49 #endif
humlet 6:5b98c902a659 50 for(int i=0; i<nTest; ++i) {
humlet 4:eafa7efcd771 51 g_freq = freq[i];
humlet 4:eafa7efcd771 52 g_len = len[i];
humlet 4:eafa7efcd771 53 printf("f=%d l=%d\n",g_freq,g_len);
humlet 4:eafa7efcd771 54 Thread::wait(500);
humlet 3:967dde37e712 55 const uint32_t dt=1e6;
humlet 3:967dde37e712 56 uint32_t tStart = us_ticker_read();
humlet 3:967dde37e712 57 uint32_t tLast = tStart;
humlet 3:967dde37e712 58 uint32_t tAct = tStart;
humlet 3:967dde37e712 59 uint32_t tMe=0;
humlet 3:967dde37e712 60 do {
humlet 3:967dde37e712 61 tAct=us_ticker_read();
humlet 14:352609d395c1 62 #if defined(TARGET_LPC1768)
humlet 14:352609d395c1 63 if(tAct==tLast+1)++tMe;
humlet 14:352609d395c1 64 #elif defined(TARGET_LPC11U24)
humlet 14:352609d395c1 65 uint32_t delta = tAct-tLast;
humlet 14:352609d395c1 66 if(delta<=2)tMe+=delta; // on the 11U24 this loop takes a bit longer than 1µs (ISR ~3µs, task switch ~8µs)
humlet 14:352609d395c1 67 #endif
humlet 3:967dde37e712 68 tLast=tAct;
humlet 3:967dde37e712 69 } while(tAct-tStart<dt);
humlet 3:967dde37e712 70 printf("dc=%5.2f \n", 100.0*(float)tMe/dt);
humlet 14:352609d395c1 71 g_disco=5;
humlet 4:eafa7efcd771 72 while(g_disco>0);
humlet 3:967dde37e712 73 }
humlet 3:967dde37e712 74 return 0;
humlet 3:967dde37e712 75 }