Diff: i2c_bit_banged.cpp

Revision:

3:43cb067ecd00

Parent:

2:8e7b51353f32

Child:

4:28cc0cf01570

diff -r 8e7b51353f32 -r 43cb067ecd00 i2c_bit_banged.cpp
--- a/i2c_bit_banged.cpp	Mon Jun 08 13:46:52 2020 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,466 +0,0 @@
-#include "mbed.h"
-#include "Alternator.h"
-
-#define I2CTEST
-
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifdef  I2CTEST
-extern  Serial  pc;
-extern  I2C i2c;
-const int ACK     = 1;  //  but acknowledge is 0, NAK is 1 6/6/2020 think this should be 1
-
-#else
-
-extern  Serial  pc;
-DigitalInOut    SDA (D4);       //  Horrible bodge to get i2c working using bit banging.
-DigitalInOut    SCL (D5);       //  DigitalInOut do not work as you might expect. Fine if used only as OpenDrain opuputs though!
-DigitalIn       SDA_IN  (A4);   //  That means paralleling up with two other pins as inputs
-DigitalIn       SCL_IN  (A5);   //  This works but is a pain. Inbuilt I2C should have worked but never does on small boards with 32 pin cpu.
-const int ACK     = 0;  //  but acknowledge is 0, NAK is 1
-#endif
-#ifdef  TARGET_NUCLEO_F401RE    //
-extern  BufferedSerial  pc;
-extern  I2C i2c;
-const int ACK     = 1;  //  but acknowledge is 0, NAK is 1
-#endif
-#endif
-const int _24LC_rd = 0xa1;  //  set bit 0 for read, clear bit 0 for write
-const int _24LC_wr = 0xa0;  //  set bit 0 for read, clear bit 0 for write
-
-
-/*struct  optpar  {
-    int min, max, def;  //  min, max, default
-    const char * t;     //  description
-}   ;*/
-struct  optpar option_list2[] = {
-    {0, 100, 1, "max pwm% @ Eng RPM 0, 0 to 100"},
-    {0, 100, 1, "max pwm% @ Eng RPM 500, 0 to 100"},
-    {0, 100, 1, "max pwm% @ Eng RPM 1000, 0 to 100"},
-    {0, 100, 1, "max pwm% @ Eng RPM 1500, 0 to 100"},
-    {0, 100, 1, "max pwm% @ Eng RPM 2000, 0 to 100"},
-    {0, 100, 10, "max pwm% @ Eng RPM 2500, 0 to 100"},
-    {0, 100, 60, "max pwm% @ Eng RPM 3000, 0 to 100"},
-    {0, 100, 70, "max pwm% @ Eng RPM 3500, 0 to 100"},
-    {0, 100, 60, "max pwm% @ Eng RPM 4000, 0 to 100"},
-    {0, 100, 50, "max pwm% @ Eng RPM 4500, 0 to 100"},
-    {0, 100, 40, "max pwm% @ Eng RPM 5000, 0 to 100"},
-    {0, 100, 33, "max pwm% @ Eng RPM 5500, 0 to 100"},
-    {0, 100, 30, "max pwm% @ Eng RPM 6000, 0 to 100"},
-    {0, 100, 30, "max pwm% @ Eng RPM 6500, 0 to 100"},
-    {0, 100, 40, "max pwm% @ Eng RPM 7000, 0 to 100"},
-    {0, 100, 50, "max pwm% @ Eng RPM 7500, 0 to 100"},
-    {0, 100, 60, "max pwm% @ Eng RPM 8000, 0 to 100"},
-    {0, 100, 0, "Future 2"},
-    {0, 100, 0, "Future 3"},
-    {0, 100, 0, "Future 4"},
-    {0, 100, 0, "Future 5"},
-    {0, 100, 0, "Future 6"},
-    {0, 100, 0, "Future 7"},
-    {0, 100, 0, "Future 8"},
-    {0, 100, 0, "Future 9"},
-    {0, 100, 0, "Future 10"},
-    {0, 100, 0, "Future 11"},
-    {0, 100, 0, "Future 12"},
-    {0, 100, 0, "Future 13"},
-}   ;
-
-const   int    numof_eeprom_options2    = sizeof(option_list2) / sizeof (struct optpar);
-
-bool    wr_24LC64  (int start_addr, char * source, int length)   ;  //  think this works
-bool    rd_24LC64  (int start_addr, char * source, int length)   ;  //  think this works
-
-
-
-eeprom_settings user_settings  ;
-
-eeprom_settings::eeprom_settings    ()  {}
-
-bool    eeprom_settings::set_defaults   ()  {
-    for (int i = 0; i < numof_eeprom_options2; i++)
-        settings[i] = option_list2[i].def;       //  Load defaults and 'Save Settings'
-    return  save    ();
-}
-
-char    eeprom_settings::rd  (uint32_t i)  {           //  Read one setup char value from private buffer 'settings'
-    if  (i > 31)    {
-        pc.printf   ("ERROR Attempt to read setting %d\r\n", i);
-        return  0;
-    }
-    return  settings[i];
-}
-
-bool    eeprom_settings::rd  (char * c, uint32_t i)  {           //  Read one setup char value from private buffer 'settings'
-    if  (i > 31)    {
-        pc.printf   ("ERROR Attempt to read setting %d\r\n", i);
-        return  false;
-    }
-    *c = settings[i];
-    return  true;
-}
-
-bool    eeprom_settings::wr  (char c, uint32_t i)  {           //  Write one setup char value to private buffer 'settings'
-    if  (i > 31)
-        return  false;
-    settings[i] = c;
-    return  true;
-}
-
-/*double  eeprom_settings::get_pwm (int rpm)   {
-    int p = rpm * lut_size;
-    p /= 8000;  //  8000 is upper RPM limit, p now scaled to sizeof lut
-    if  (p < 0) p = 0;                    //  point to first
-    if  (p >= lut_size) p = lut_size - 1; //  point to last
-//    pc.printf   ("In get_pwm, rpm = %d, lut entry = %d, pwm = %d\r\n", rpm, p, max_pwm_lut[p]);
-    return  max_pwm_lut[p];
-}*/
-
-/*void    eeprom_settings::build_lut   ()  {
-    int ptr = 0;
-    int range, i;
-    double  acc = 0.0, incr = 0.0;
-    for (i = 0; i < 8; i++) {
-        range = user_settings.rd(i+1) - user_settings.rd(i);  //  range now change in percent between two 'n'000 RPMs
-        incr = (double)range;
-        incr /= 100.0;  //  percent
-        incr /= lut_seg_size;
-        for(int j = 0; j < lut_seg_size; j++)   {
-            max_pwm_lut[ptr++] = acc;
-            acc += incr;
-        }
-    }
-    max_pwm_lut[ptr] = (int)acc;
-    pc.printf   ("At end of build_lut ptr=%d\r\n", ptr);
-    range = 0;
-
-    while   (range < ptr)   {
-        for (i = 0; i < 8; i++)    {
-            pc.printf   ("%.3f\t", max_pwm_lut[range++]);
-        }
-        pc.printf   ("\r\n");
-    }
-    pc.printf   ("lut_size = %d\r\n", lut_size);
-
-}*/
-
-bool    eeprom_settings::load    ()  {               //  Get 'settings' buffer from EEPROM
-    bool    rv  ;
-    rv =    rd_24LC64   (eeprom_page * 32, settings, 32);   //  Can now build lookup table
-//Apr2020    build_lut   ();
-    return  rv;
-}
-
-bool    eeprom_settings::save    ()  {               //  Write 'settings' buffer to EEPROM
-    return  wr_24LC64   (eeprom_page * 32, settings, 32);
-}
-
-
-//#ifdef  TARGET_NUCLEO_L432KC    //
-
-/**
-*   bool    i2c_init(void) {
-*
-*   Init function. Needs to be called once in the beginning.
-*   Returns false if SDA or SCL are low, which probably means 
-*   a I2C bus lockup or that the lines are not pulled up.
-*/
-bool    i2c_init(void) {
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifndef I2CTEST
-    SDA.output();
-    SCL.output();
-    SDA.mode(OpenDrain);
-    SCL.mode(OpenDrain);    //  Device may pull clock lo to indicate to master
-    SDA = 0;
-    SCL = 0;
-    wait_us   (1);
-    SDA = 1;
-    wait_us (1);
-    SCL = 1;
-    wait_us (1);
-    if  (SCL_IN == 0 || SDA_IN == 0)    return  false;
-#endif
-#endif
-#ifdef  TARGET_NUCLEO_F401RE    //
-//    return  i2c.init    ()  ; //  class has no member "init"
-#endif
-    return  true;
-}
-
-/**
-*   During data transfer, the data line must remain 
-*   stable whenever the clock line is high. Changes in 
-*   the data line while the clock line is high will be 
-*   interpreted as a Start or Stop condition
-*
-*   A high-to-low transition of the SDA line while the clock
-*   (SCL)   is   high   determines   a   Start   condition.   All
-*   commands must be preceded by a Start condition.
-*/
-int i2c_start  ()  {   // Should be Both hi, start takes SDA low
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifndef I2CTEST
-    int    rv = 0;
-    if  (SDA_IN == 0 )  {
-        rv |= 1;    //  Fault - SDA was lo on entry
-        SDA = 1;
-        wait_us (1);
-    }
-    if  (SCL == 0 )  {
-        rv |= 2;    //  Fault - SCL was lo on entry
-        SCL = 1;
-        wait_us (1);
-    }
-    SDA = 0;                    //  Take SDA lo
-    wait_us (1);
-    SCL = 0;
-    wait_us (1);
-    return  rv;     //  Returns 0 on success, 1 with SDA fault, 2 with SCL fault, 3 with SDA and SCL fault
-#else
-    i2c.start   ()  ;
-    return  0;
-
-#endif
-#endif
-#ifdef  TARGET_NUCLEO_F401RE    //
-    i2c.start   ()  ;
-    return  0;
-#endif
-}
-
-/**
-*   During data transfer, the data line must remain 
-*   stable whenever the clock line is high. Changes in 
-*   the data line while the clock line is high will be 
-*   interpreted as a Start or Stop condition
-*
-*   A low-to-high transition of the SDA line while the clock
-*   (SCL)   is   high   determines   a   Stop   condition.   All
-*   operations must be ended with a Stop condition.
-*/
-int i2c_stop  ()  {   //  Should be SDA=0, SCL=1, start takes SDA hi
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifdef  I2CTEST
-    i2c.stop    ()  ;
-    return  0;
-#else
-    int    rv = 0;
-    SDA = 0;    //  Pull SDA to 0
-    wait_us (1);
-    if  (SCL_IN != 0)   {
-        pc.printf   ("SCL 1 on entry to stop\r\n");
-        SCL = 0;    //  pull SCL to 0 if not there already
-        wait_us (1);
-    }
-    SCL = 1;
-    wait_us (1);
-    if  (SCL_IN == 0)
-        pc.printf   ("SCL stuck lo in stop\r\n");
-    SDA = 1;
-    wait_us (1);
-    if  (SDA_IN == 0)
-        pc.printf   ("SDA stuck lo in stop\r\n");
-    return  rv;     //  Returns 0 on success, 1 with SDA fault, 2 with SCL fault, 3 with SDA and SCL fault
-#endif
-#endif
-#ifdef  TARGET_NUCLEO_F401RE    //
-    i2c.stop    ()  ;
-    return  0;
-#endif
-}
-
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifndef I2CTEST
-void    jclk    (int bit)   {
-    SCL = bit;
-    wait_us (1);
-}
-
-void    jclkout ()  {
-    wait_us (1);
-    SCL = 1;
-    wait_us (1);
-    SCL = 0;
-    wait_us (1);
-}
-#endif
-#endif
-
-int i2c_write (int    d)  {
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifdef  I2CTEST
-    return  i2c.write   (d);
-#else
-    int ackbit = 0;
-    if  (SCL_IN != 0)   {
-        pc.printf   ("SCL hi on entry to write\r\n");
-        jclk    (0);
-    }
-    for (int i = 0x80; i != 0; i >>= 1) {        //  bit out msb first
-        if  ((d & i) == 0)  SDA = 0;
-        else                SDA = 1;
-        jclkout ();     //  SCL ____---____
-    }
-    SDA = 1;    //  Release data to allow remote device to pull lo for ACK or not
-    jclk    (1);    //  SCL = 1
-    ackbit = SDA_IN;   //  read in ack bit
-    jclk    (0);    //  SCL = 0
-//    pc.printf   ("wr 0x%x %s\r\n", d, ackbit == 0 ? "ACK" : "nak");
-    return  ackbit; //      0 for acknowledged ACK, 1 for NAK
-#endif
-#endif
-#ifdef  TARGET_NUCLEO_F401RE    //
-    return  i2c.write   (d);
-#endif
-}
-
-
-
-
-int i2c_read    (int acknak)  {     //  acknak  indicates if the byte is to be acknowledged (0 = acknowledge)
-#ifdef  TARGET_NUCLEO_L432KC    //
-#ifdef  I2CTEST
-    return  i2c.read    (acknak)    ;
-#else
-    int result = 0;                 //  SCL should be 1 on entry
-    SDA = 1;        //  Master released SDA
-    if  (SCL_IN != 0)   pc.printf   ("SCL hi arriving at read\r\n");
-    wait_us (2);
-    for (int i = 0; i < 8; i++) {
-        result <<= 1;
-        jclk    (1);
-        if  (SDA_IN != 0)  result |= 1;
-        jclk    (0);
-    }
-    if  (acknak != 0 && acknak != 1)
-        pc.printf   ("Bad acknak in 12c_read %d\r\n", acknak);
-    if  (acknak == 0)   SDA = 0;
-    else                SDA = 1;
-    jclkout ();    //  clock out the ACK bit __--__
-//    pc.printf   ("rd 0x%x %s\r\n", result, acknak == 0 ? "ACK" : "nak");
-    return  result;             //  Always ? nah
-#endif
-#endif
-#ifdef  TARGET_NUCLEO_F401RE    //
-    return  i2c.read    (acknak)    ;
-#endif
-}
-
-int check_24LC64   ()  {     //  Call from near top of main() to init i2c bus
-    int last_found = 0, q, e;      //  Note address bits 3-1 to match addr pins on device
-    for (int i = 0; i < 255; i += 2)    {   //  Search for devices at all possible i2c addresses
-        e = i2c_start();
-        if  (e) pc.putc(',');
-        q = i2c_write(i);   //  may return error code 2 when no start issued
-        if  (q == ACK)  {
-            pc.printf   ("I2C device found at 0x%x\r\n", i);
-            last_found = i;
-            wait_ms (5);
-        }
-        i2c_stop();
-    }
-    return  last_found;
-}
-
-
-
-
-
-
-
-
-bool    ack_poll    ()  {   //  wait short while for any previous memory operation to complete
-    const int poll_tries    = 40;
-    int poll_count = 0;
-    bool    i2cfree = false;
-    while   (poll_count++ < poll_tries && !i2cfree)  {
-        i2c_start   ();
-        if  (i2c_write(_24LC_wr) == ACK)
-            i2cfree = true;
-        else
-            wait_ms   (1);
-    }
-//    pc.printf   ("ack_poll, count = %d, i2cfree = %s\r\n", poll_count, i2cfree ? "true" : "false");
-    return  i2cfree;
-}
-
-/**bool    set_24LC64_internal_address (int    start_addr)   {
-*
-*
-*
-*/
-bool    set_24LC64_internal_address (int    start_addr)   {
-    if  (!ack_poll())
-    {
-        pc.printf   ("Err in set_24LC64_internal_address, no ACK writing device address byte\r\n");
-        i2c_stop();
-        return  false;
-    }
-    int err = 0;
-    if  (i2c_write(start_addr >> 8)   != ACK) err++;
-    if  (i2c_write(start_addr & 0xff) != ACK) err++;
-    if  (err)   {
-        pc.printf   ("In set_24LC64_internal_address, Believe Device present, failed in writing 2 mem addr bytes %d\r\n", err);
-        i2c_stop();
-        return  false;
-    }
-//    pc.printf   ("GOOD set_24LC64_internal_address %d\r\n", start_addr);
-    return  true;
-}
-
-bool    wr_24LC64  (int start_addr, char * source, int length)   {  //  think this works
-    int err = 0;
-    if(length < 1 || length > 32)   {
-        pc.printf   ("Length out of range %d in wr_24LC64\r\n", length);
-        return  false;
-    }
-    ack_poll    ();
-    if  (!set_24LC64_internal_address   (start_addr))   {
-        pc.printf   ("In wr_24LC64, Believe Device present, failed in writing 2 mem addr bytes %d\r\n", err);
-        return  false;
-    }
-    while(length--) 
-        if  (i2c_write(*source++) != ACK)
-            err++;
-//        err += i2c_write(*source++);
-    i2c_stop();
-    if  (err)   {
-        pc.printf   ("in wr_24LC64, device thought good, mem addr write worked, failed writing string\r\n");
-        return  false;
-    }
-//    pc.printf   ("In wr_24LC64 No Errors Found!\r\n");
-    return  true;
-}
-
-bool rd_24LC64  (int start_addr, char * dest, int length)   {
-    int acknak = ACK;
-    if(length < 1)
-        return false;
-    if  (!set_24LC64_internal_address   (start_addr))   {
-        pc.printf   ("In rd_24LC64, failed to set_ramaddr\r\n");
-        return  false;
-    }
-    i2c_start();
-    if  (i2c_write(_24LC_rd) != ACK) {
-        pc.printf   ("Errors in rd_24LC64 sending 24LC_rd\r\n");
-        return  false;
-    }
-    while(length--) {
-        if(length == 0)
-            acknak = 1;
-        *dest++ = i2c_read(acknak);
-    }
-    i2c_stop();
-    return  true;
-}
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