Yihui Xiong / Mbed 2 deprecated Seeed_nRF51822_Motion

initial

Dependencies:   mbed

eMPL_MPU/mbed_i2c.c@1:9d3b497333c0, 2016-01-11 (annotated)

Committer:
yihui
Date:
Mon Jan 11 02:49:25 2016 +0000
Revision:
1:9d3b497333c0
Parent:
0:638edba3adf6 
use mbed lib

Who changed what in which revision?

UserRevisionLine numberNew contents of line
yihui 0:638edba3adf6 1
yihui 0:638edba3adf6 2 #include <stdio.h>
yihui 0:638edba3adf6 3 #include "i2c_api.h"
yihui 0:638edba3adf6 4 #include "gpio_api.h"
yihui 0:638edba3adf6 5 #include "wait_api.h"
yihui 0:638edba3adf6 6
yihui 0:638edba3adf6 7 #ifdef TARGET_MCU_NRF51822
yihui 0:638edba3adf6 8 #include "nrf51.h"
yihui 0:638edba3adf6 9 static PinName mbed_i2c_sda_pin = NC;
yihui 0:638edba3adf6 10 static PinName mbed_i2c_scl_pin = NC;
yihui 0:638edba3adf6 11 static uint32_t mbed_i2c_sda_cnf;
yihui 0:638edba3adf6 12 static uint32_t mbed_i2c_scl_cnf;
yihui 0:638edba3adf6 13 #endif
yihui 0:638edba3adf6 14
yihui 0:638edba3adf6 15 static i2c_t mbed_i2c_object = {0,};
yihui 0:638edba3adf6 16
yihui 0:638edba3adf6 17
yihui 0:638edba3adf6 18 void mbed_i2c_init(PinName sda, PinName scl)
yihui 0:638edba3adf6 19 {
yihui 0:638edba3adf6 20
yihui 0:638edba3adf6 21 mbed_i2c_sda_pin = sda;
yihui 0:638edba3adf6 22 mbed_i2c_scl_pin = scl;
yihui 0:638edba3adf6 23
yihui 0:638edba3adf6 24 i2c_init(&mbed_i2c_object, sda, scl);
yihui 0:638edba3adf6 25 i2c_frequency(&mbed_i2c_object, 100000);
yihui 0:638edba3adf6 26 }
yihui 0:638edba3adf6 27
yihui 0:638edba3adf6 28 int mbed_i2c_write(unsigned char slave_addr,
yihui 0:638edba3adf6 29 unsigned char reg_addr,
yihui 0:638edba3adf6 30 unsigned char length,
yihui 0:638edba3adf6 31 unsigned char const *data)
yihui 0:638edba3adf6 32 {
yihui 0:638edba3adf6 33 int i;
yihui 0:638edba3adf6 34 slave_addr = slave_addr << 1;
yihui 0:638edba3adf6 35 i2c_start(&mbed_i2c_object);
yihui 0:638edba3adf6 36 i2c_byte_write(&mbed_i2c_object, slave_addr);
yihui 0:638edba3adf6 37 i2c_byte_write(&mbed_i2c_object, reg_addr);
yihui 0:638edba3adf6 38 for (i = 0; i < length; i++) {
yihui 0:638edba3adf6 39 i2c_byte_write(&mbed_i2c_object, data[i]);
yihui 0:638edba3adf6 40 }
yihui 0:638edba3adf6 41 i2c_stop(&mbed_i2c_object);
yihui 0:638edba3adf6 42 return 0;
yihui 0:638edba3adf6 43 }
yihui 0:638edba3adf6 44
yihui 0:638edba3adf6 45 int mbed_i2c_read(unsigned char slave_addr,
yihui 0:638edba3adf6 46 unsigned char reg_addr,
yihui 0:638edba3adf6 47 unsigned char length,
yihui 0:638edba3adf6 48 unsigned char *data)
yihui 0:638edba3adf6 49 {
yihui 0:638edba3adf6 50 slave_addr = slave_addr << 1;
yihui 0:638edba3adf6 51 i2c_write(&mbed_i2c_object, slave_addr, &reg_addr, 1, 0);
yihui 0:638edba3adf6 52 return (i2c_read(&mbed_i2c_object, slave_addr, data, length, 1) == length) ? 0 : 1;
yihui 0:638edba3adf6 53 }
yihui 0:638edba3adf6 54
yihui 0:638edba3adf6 55 int mbed_i2c_clear(PinName sda, PinName scl)
yihui 0:638edba3adf6 56 {
yihui 0:638edba3adf6 57 gpio_t sda_io, scl_io;
yihui 0:638edba3adf6 58
yihui 0:638edba3adf6 59 #ifdef TARGET_MCU_NRF51822
yihui 0:638edba3adf6 60 uint32_t sda_cnf = NRF_GPIO->PIN_CNF[sda];
yihui 0:638edba3adf6 61 uint32_t scl_cnf = NRF_GPIO->PIN_CNF[scl];
yihui 0:638edba3adf6 62 if (mbed_i2c_object.i2c) {
yihui 0:638edba3adf6 63 mbed_i2c_object.i2c->PSELSCL = 0xFFFFFFFF;
yihui 0:638edba3adf6 64 mbed_i2c_object.i2c->PSELSDA = 0xFFFFFFFF;
yihui 0:638edba3adf6 65 }
yihui 0:638edba3adf6 66 #endif
yihui 0:638edba3adf6 67
yihui 0:638edba3adf6 68 gpio_init_in(&sda_io, sda);
yihui 0:638edba3adf6 69
yihui 0:638edba3adf6 70 if (!gpio_read(&sda_io)) {
yihui 0:638edba3adf6 71 printf("sda is always 0, i2c bus is not released\r\n");
yihui 0:638edba3adf6 72 printf("try to clear i2c bus\r\n");
yihui 0:638edba3adf6 73 gpio_init_out(&scl_io, scl);
yihui 0:638edba3adf6 74
yihui 0:638edba3adf6 75 // Clock max 18 pulses worst case scenario(9 for master to send the rest of command and 9
yihui 0:638edba3adf6 76 // for slave to respond) to SCL line and wait for SDA come high.
yihui 0:638edba3adf6 77 for (int i = 0; i < 18; i++) {
yihui 0:638edba3adf6 78 gpio_write(&scl_io, 0);
yihui 0:638edba3adf6 79 wait_us(4);
yihui 0:638edba3adf6 80 gpio_write(&scl_io, 1);
yihui 0:638edba3adf6 81 wait_us(4);
yihui 0:638edba3adf6 82 }
yihui 0:638edba3adf6 83
yihui 0:638edba3adf6 84 if (!gpio_read(&sda_io)) {
yihui 0:638edba3adf6 85 printf("warning! sda is still 0,, i2c bus is not released\r\n");
yihui 0:638edba3adf6 86 }
yihui 0:638edba3adf6 87 }
yihui 0:638edba3adf6 88
yihui 0:638edba3adf6 89 #ifdef TARGET_MCU_NRF51822
yihui 0:638edba3adf6 90 NRF_GPIO->PIN_CNF[sda] = sda_cnf;
yihui 0:638edba3adf6 91 NRF_GPIO->PIN_CNF[scl] = scl_cnf;
yihui 0:638edba3adf6 92 if (mbed_i2c_object.i2c) {
yihui 0:638edba3adf6 93 mbed_i2c_object.i2c->PSELSCL = scl;
yihui 0:638edba3adf6 94 mbed_i2c_object.i2c->PSELSDA = sda;
yihui 0:638edba3adf6 95 }
yihui 0:638edba3adf6 96 #endif
yihui 0:638edba3adf6 97
yihui 0:638edba3adf6 98 return 0;
yihui 0:638edba3adf6 99 }
yihui 0:638edba3adf6 100
yihui 0:638edba3adf6 101 void mbed_i2c_enable(void)
yihui 0:638edba3adf6 102 {
yihui 0:638edba3adf6 103 #ifdef TARGET_MCU_NRF51822
yihui 0:638edba3adf6 104 NRF_GPIO->PIN_CNF[mbed_i2c_sda_pin] = mbed_i2c_sda_cnf;
yihui 0:638edba3adf6 105 NRF_GPIO->PIN_CNF[mbed_i2c_scl_pin] = mbed_i2c_scl_cnf;
yihui 0:638edba3adf6 106
yihui 0:638edba3adf6 107 mbed_i2c_object.i2c->ENABLE = 4;
yihui 0:638edba3adf6 108 #endif
yihui 0:638edba3adf6 109 }
yihui 0:638edba3adf6 110
yihui 0:638edba3adf6 111 void mbed_i2c_disable(void)
yihui 0:638edba3adf6 112 {
yihui 0:638edba3adf6 113 #ifdef TARGET_MCU_NRF51822
yihui 0:638edba3adf6 114 mbed_i2c_sda_cnf = NRF_GPIO->PIN_CNF[mbed_i2c_sda_pin];
yihui 0:638edba3adf6 115 mbed_i2c_scl_cnf = NRF_GPIO->PIN_CNF[mbed_i2c_scl_pin];
yihui 0:638edba3adf6 116
yihui 0:638edba3adf6 117 mbed_i2c_object.i2c->ENABLE = 0;
yihui 0:638edba3adf6 118
yihui 0:638edba3adf6 119 NRF_GPIO->PIN_CNF[mbed_i2c_sda_pin] = 2;
yihui 0:638edba3adf6 120 NRF_GPIO->PIN_CNF[mbed_i2c_scl_pin] = 2;
yihui 0:638edba3adf6 121 #endif
yihui 0:638edba3adf6 122 }