alan broad / Mbed OS carbon_v5_arm_studio

arm studio build

Dependencies:   libxDot-mbed5

src/commI2C.cpp@2:0af50f386eb2, 2018-08-04 (annotated)

Committer:
alan1974
Date:
Sat Aug 04 19:56:33 2018 +0000
Revision:
2:0af50f386eb2
Parent:
0:a91cd1b08360
Child:
5:abfe25f0de33
update

Who changed what in which revision?

UserRevisionLine numberNew contents of line
alan1974 0:a91cd1b08360 1 #include "mbed.h"
alan1974 2:0af50f386eb2 2 #include "global.h"
alan1974 0:a91cd1b08360 3 #include "commI2C.h"
alan1974 0:a91cd1b08360 4
alan1974 0:a91cd1b08360 5 extern uint8_t buf_xmt[BUFFER_SIZE_I2C]; //outgoing data
alan1974 0:a91cd1b08360 6 extern uint8_t buf_rcv[BUFFER_SIZE_I2C]; //incoming data
alan1974 0:a91cd1b08360 7 I2CSlave slave(PB_9, PB_8);
alan1974 0:a91cd1b08360 8 DigitalInOut wake(PA_0);
alan1974 0:a91cd1b08360 9
alan1974 0:a91cd1b08360 10 extern Serial pc;
alan1974 0:a91cd1b08360 11 //#define TEST
alan1974 0:a91cd1b08360 12
alan1974 0:a91cd1b08360 13
alan1974 0:a91cd1b08360 14 //==============================================================================
alan1974 0:a91cd1b08360 15 // i2c_proc_init
alan1974 0:a91cd1b08360 16 // - init i2c comm to proc
alan1974 0:a91cd1b08360 17 //==============================================================================
alan1974 0:a91cd1b08360 18 void i2c_proc_init()
alan1974 0:a91cd1b08360 19 {
alan1974 0:a91cd1b08360 20 slave.frequency(100000); // added DRT NOT NEEDED BY SLAVE????,asb, need this ????
alan1974 0:a91cd1b08360 21 uint8_t slave_address = 0xA0; //PROC code uses 7bit address shifted by one so 0xA0 (xdot) => 0x50 (PROC)
alan1974 0:a91cd1b08360 22 slave.address(slave_address);
alan1974 0:a91cd1b08360 23 //set wake hi
alan1974 0:a91cd1b08360 24
alan1974 0:a91cd1b08360 25 return;
alan1974 0:a91cd1b08360 26 }
alan1974 0:a91cd1b08360 27 //==============================================================================
alan1974 0:a91cd1b08360 28 // i2c_wait4wake_lo
alan1974 0:a91cd1b08360 29 // - wait for the wake signal from proc to go low
alan1974 0:a91cd1b08360 30 // NEEDS TO BE CORRECTED, THIS WAITS FOR A HI THEN A LOW !!!!
alan1974 0:a91cd1b08360 31 //==============================================================================
alan1974 0:a91cd1b08360 32 #ifdef NOT_USED
alan1974 0:a91cd1b08360 33 void i2c_wait4wake_lo(void){
alan1974 0:a91cd1b08360 34 wake.input();
alan1974 0:a91cd1b08360 35 // pc.printf("\n\r waiting for wake to go hi %d",wake);
alan1974 0:a91cd1b08360 36 bool wakeHi= false;
alan1974 0:a91cd1b08360 37 while(!wakeHi){
alan1974 0:a91cd1b08360 38 wait_ms(10); //need this wait else loop below will block previous printout
alan1974 0:a91cd1b08360 39 wakeHi = wake; // state of wake signal
alan1974 0:a91cd1b08360 40 }
alan1974 0:a91cd1b08360 41 // pc.printf("\n\r detected wake hi");
alan1974 0:a91cd1b08360 42 wait_ms(100); //need this wait else loop below will block previous printout
alan1974 0:a91cd1b08360 43 //wake signal hi,wait until it goes back lo => psoc is going to wait for ....
alan1974 0:a91cd1b08360 44 // pc.printf("\n\r waiting for wake to go lo %d",wake);
alan1974 0:a91cd1b08360 45 bool wakeLo = true;
alan1974 0:a91cd1b08360 46 while(wakeLo){
alan1974 0:a91cd1b08360 47 wait_ms(10); //need this wait else loop below will block previous printout
alan1974 0:a91cd1b08360 48 wakeLo = wake; // state of wake signal
alan1974 0:a91cd1b08360 49 }
alan1974 0:a91cd1b08360 50 //pc.printf("\n\r detected wake lo ");
alan1974 0:a91cd1b08360 51 wait_ms(100); //wait for proc to get ready for i2c comm, proc leave wake in low state
alan1974 0:a91cd1b08360 52
alan1974 0:a91cd1b08360 53
alan1974 0:a91cd1b08360 54 return;
alan1974 0:a91cd1b08360 55 }
alan1974 0:a91cd1b08360 56 #endif
alan1974 0:a91cd1b08360 57 //==============================================================================
alan1974 0:a91cd1b08360 58 // i2c_pulse_wake
alan1974 0:a91cd1b08360 59 // - pulse the wake signal to tell proc that xdot ready for i2c xfr
alan1974 0:a91cd1b08360 60 //==============================================================================
alan1974 0:a91cd1b08360 61 void i2c_pulse_wake(void){
alan1974 0:a91cd1b08360 62 wake.mode(OpenDrain);
alan1974 0:a91cd1b08360 63 wake.output();
alan1974 0:a91cd1b08360 64 wake = 1;
alan1974 0:a91cd1b08360 65 wait_ms(10); //proc uses interrupts on lora_wake, so don't need to wait,just pulse it
alan1974 0:a91cd1b08360 66 wake = 0; // set wake lo
alan1974 0:a91cd1b08360 67 wait_ms(1);
alan1974 0:a91cd1b08360 68 wake.input(); //go back to input mode !!! wake pull hi if go back to input mode ???
alan1974 0:a91cd1b08360 69 return;
alan1974 0:a91cd1b08360 70 }
alan1974 0:a91cd1b08360 71 //==============================================================================
alan1974 0:a91cd1b08360 72 // i2c_proc_comm
alan1974 0:a91cd1b08360 73 //- set WAKE low to notify proc that's OK to read/write i2c data
alan1974 0:a91cd1b08360 74 //- waits FOREVER or timeout for proc to write or read i2 data
alan1974 0:a91cd1b08360 75 // - returns point to read or write i2c bfr
alan1974 0:a91cd1b08360 76 //- returns true if xdot rcvd data into buf_rcv from proc
alan1974 0:a91cd1b08360 77 // false if xdot wrote data from buf_xmt to proc
alan1974 0:a91cd1b08360 78 //- before returning sets WAKE hi
alan1974 0:a91cd1b08360 79 //------------------------------------------------------------------------------
alan1974 0:a91cd1b08360 80 // xdot i2c slave operation:
alan1974 0:a91cd1b08360 81 // - xdot does not work correctly as a i2c slave
alan1974 0:a91cd1b08360 82 // - if xdot does not respond to first incoming bytes from master (responseTime)
alan1974 0:a91cd1b08360 83 // within a defined period the xdot will hang the i2c bus until it is reset
alan1974 0:a91cd1b08360 84 // - the strategy here is sit in a very tight while loop polling continually for
alan1974 0:a91cd1b08360 85 // incoming i2c bytee within the respnseTime
alan1974 0:a91cd1b08360 86 // - the time around the while loop below must be < responseTime
alan1974 0:a91cd1b08360 87 // - reponseTime for the while loop below is measured at 1.25 usec
alan1974 0:a91cd1b08360 88 // - responseTimes upto 80 usec have been measured to be OK
alan1974 0:a91cd1b08360 89 //------------------------------------------------------------------------------
alan1974 0:a91cd1b08360 90 // timeout:
alan1974 0:a91cd1b08360 91 // - safety mechanism to get xdot back to sleep mode if proc goes unresponsive
alan1974 0:a91cd1b08360 92 // - cpu clock dependant..what mhz is cpu? presently this will give 1.1sec timout before
alan1974 0:a91cd1b08360 93 // - 0x000fffff gives a 1.1 second timeout
alan1974 0:a91cd1b08360 94 // - after proc wakes xdot from sleep then proc must send an i2c omd within timout
alan1974 0:a91cd1b08360 95 // - once xdot pulses wake to notify proc that i2c ack msg is ready, proc must do i2c read within timeout
alan1974 0:a91cd1b08360 96 //==============================================================================
alan1974 0:a91cd1b08360 97 I2C_XFR_TYPE i2c_proc_comm(void)
alan1974 0:a91cd1b08360 98 {
alan1974 0:a91cd1b08360 99 bool verbose = false;
alan1974 0:a91cd1b08360 100 uint32_t timeout = 0x000fffff; //1.1second timeout
alan1974 0:a91cd1b08360 101
alan1974 0:a91cd1b08360 102 while(1){
alan1974 0:a91cd1b08360 103 int i = slave.receive();
alan1974 0:a91cd1b08360 104 switch (i) {
alan1974 0:a91cd1b08360 105 case I2CSlave::ReadAddressed: //xdot -> proc
alan1974 0:a91cd1b08360 106 slave.write((char *)buf_xmt, BUFFER_SIZE_I2C);
alan1974 0:a91cd1b08360 107 return I2C_WRITE;
alan1974 0:a91cd1b08360 108 case I2CSlave::WriteAddressed: //xdot <- proc
alan1974 0:a91cd1b08360 109 slave.read((char *)buf_rcv, BUFFER_SIZE_I2C);
alan1974 0:a91cd1b08360 110 if (verbose){
alan1974 0:a91cd1b08360 111 pc.printf("\n\r Incoming buffer(hex): \n\r");
alan1974 0:a91cd1b08360 112 int j;
alan1974 0:a91cd1b08360 113 for (j = 0; j < BUFFER_SIZE_I2C; j++){
alan1974 0:a91cd1b08360 114 pc.printf("%x", buf_rcv[j]);
alan1974 0:a91cd1b08360 115 pc.printf(" ");
alan1974 0:a91cd1b08360 116 }
alan1974 0:a91cd1b08360 117
alan1974 0:a91cd1b08360 118 }
alan1974 0:a91cd1b08360 119 return I2C_READ;
alan1974 0:a91cd1b08360 120 default:
alan1974 0:a91cd1b08360 121 }; //switch
alan1974 0:a91cd1b08360 122
alan1974 0:a91cd1b08360 123 timeout--;
alan1974 0:a91cd1b08360 124 if(timeout == 0)return I2C_WRITE; //just go to sleep
alan1974 0:a91cd1b08360 125 }; //while
alan1974 0:a91cd1b08360 126 }