MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/twi_master.c@46:b156ef445742, 2017-06-03 (annotated)

Committer:
sahilmgandhi
Date:
Sat Jun 03 00:22:44 2017 +0000
Revision:
46:b156ef445742
Parent:
18:6a4db94011d3 
Final code for internal battlebot competition.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sahilmgandhi 18:6a4db94011d3 1 /* Copyright (c) 2009 Nordic Semiconductor. All Rights Reserved.
sahilmgandhi 18:6a4db94011d3 2 *
sahilmgandhi 18:6a4db94011d3 3 * The information contained herein is property of Nordic Semiconductor ASA.
sahilmgandhi 18:6a4db94011d3 4 * Terms and conditions of usage are described in detail in NORDIC
sahilmgandhi 18:6a4db94011d3 5 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
sahilmgandhi 18:6a4db94011d3 6 *
sahilmgandhi 18:6a4db94011d3 7 * Licensees are granted free, non-transferable use of the information. NO
sahilmgandhi 18:6a4db94011d3 8 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
sahilmgandhi 18:6a4db94011d3 9 * the file.
sahilmgandhi 18:6a4db94011d3 10 *
sahilmgandhi 18:6a4db94011d3 11 */
sahilmgandhi 18:6a4db94011d3 12
sahilmgandhi 18:6a4db94011d3 13 #include "twi_master.h"
sahilmgandhi 18:6a4db94011d3 14 #include "twi_config.h"
sahilmgandhi 18:6a4db94011d3 15 #include <stdbool.h>
sahilmgandhi 18:6a4db94011d3 16 #include <stdint.h>
sahilmgandhi 18:6a4db94011d3 17 #include "nrf.h"
sahilmgandhi 18:6a4db94011d3 18 #include "nrf_delay.h"
sahilmgandhi 18:6a4db94011d3 19
sahilmgandhi 18:6a4db94011d3 20 /* Max cycles approximately to wait on RXDREADY and TXDREADY event,
sahilmgandhi 18:6a4db94011d3 21 * This is optimized way instead of using timers, this is not power aware. */
sahilmgandhi 18:6a4db94011d3 22 #define MAX_TIMEOUT_LOOPS (20000UL) /**< MAX while loops to wait for RXD/TXD event */
sahilmgandhi 18:6a4db94011d3 23
sahilmgandhi 18:6a4db94011d3 24 static bool twi_master_write(uint8_t * data, uint8_t data_length, bool issue_stop_condition, NRF_TWI_Type* twi)
sahilmgandhi 18:6a4db94011d3 25 {
sahilmgandhi 18:6a4db94011d3 26 uint32_t timeout = MAX_TIMEOUT_LOOPS; /* max loops to wait for EVENTS_TXDSENT event*/
sahilmgandhi 18:6a4db94011d3 27
sahilmgandhi 18:6a4db94011d3 28 if (data_length == 0)
sahilmgandhi 18:6a4db94011d3 29 {
sahilmgandhi 18:6a4db94011d3 30 /* Return false for requesting data of size 0 */
sahilmgandhi 18:6a4db94011d3 31 return false;
sahilmgandhi 18:6a4db94011d3 32 }
sahilmgandhi 18:6a4db94011d3 33
sahilmgandhi 18:6a4db94011d3 34 twi->TXD = *data++;
sahilmgandhi 18:6a4db94011d3 35 twi->TASKS_STARTTX = 1;
sahilmgandhi 18:6a4db94011d3 36
sahilmgandhi 18:6a4db94011d3 37 /** @snippet [TWI HW master write] */
sahilmgandhi 18:6a4db94011d3 38 while (true)
sahilmgandhi 18:6a4db94011d3 39 {
sahilmgandhi 18:6a4db94011d3 40 while (twi->EVENTS_TXDSENT == 0 && twi->EVENTS_ERROR == 0 && (--timeout))
sahilmgandhi 18:6a4db94011d3 41 {
sahilmgandhi 18:6a4db94011d3 42 // Do nothing.
sahilmgandhi 18:6a4db94011d3 43 }
sahilmgandhi 18:6a4db94011d3 44
sahilmgandhi 18:6a4db94011d3 45 if (timeout == 0 || NRF_TWI1->EVENTS_ERROR != 0)
sahilmgandhi 18:6a4db94011d3 46 {
sahilmgandhi 18:6a4db94011d3 47 // Recover the peripheral as indicated by PAN 56: "TWI: TWI module lock-up." found at
sahilmgandhi 18:6a4db94011d3 48 // Product Anomaly Notification document found at
sahilmgandhi 18:6a4db94011d3 49 // https://www.nordicsemi.com/eng/Products/Bluetooth-R-low-energy/nRF51822/#Downloads
sahilmgandhi 18:6a4db94011d3 50 twi->EVENTS_ERROR = 0;
sahilmgandhi 18:6a4db94011d3 51 twi->ENABLE = TWI_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos;
sahilmgandhi 18:6a4db94011d3 52 twi->POWER = 0;
sahilmgandhi 18:6a4db94011d3 53 nrf_delay_us(5);
sahilmgandhi 18:6a4db94011d3 54 twi->POWER = 1;
sahilmgandhi 18:6a4db94011d3 55 twi->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;
sahilmgandhi 18:6a4db94011d3 56
sahilmgandhi 18:6a4db94011d3 57 (void)twi_master_init_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 58
sahilmgandhi 18:6a4db94011d3 59 return false;
sahilmgandhi 18:6a4db94011d3 60 }
sahilmgandhi 18:6a4db94011d3 61 twi->EVENTS_TXDSENT = 0;
sahilmgandhi 18:6a4db94011d3 62 if (--data_length == 0)
sahilmgandhi 18:6a4db94011d3 63 {
sahilmgandhi 18:6a4db94011d3 64 break;
sahilmgandhi 18:6a4db94011d3 65 }
sahilmgandhi 18:6a4db94011d3 66
sahilmgandhi 18:6a4db94011d3 67 twi->TXD = *data++;
sahilmgandhi 18:6a4db94011d3 68 }
sahilmgandhi 18:6a4db94011d3 69 /** @snippet [TWI HW master write] */
sahilmgandhi 18:6a4db94011d3 70
sahilmgandhi 18:6a4db94011d3 71 if (issue_stop_condition)
sahilmgandhi 18:6a4db94011d3 72 {
sahilmgandhi 18:6a4db94011d3 73 twi->EVENTS_STOPPED = 0;
sahilmgandhi 18:6a4db94011d3 74 twi->TASKS_STOP = 1;
sahilmgandhi 18:6a4db94011d3 75 /* Wait until stop sequence is sent */
sahilmgandhi 18:6a4db94011d3 76 while(twi->EVENTS_STOPPED == 0)
sahilmgandhi 18:6a4db94011d3 77 {
sahilmgandhi 18:6a4db94011d3 78 // Do nothing.
sahilmgandhi 18:6a4db94011d3 79 }
sahilmgandhi 18:6a4db94011d3 80 }
sahilmgandhi 18:6a4db94011d3 81 return true;
sahilmgandhi 18:6a4db94011d3 82 }
sahilmgandhi 18:6a4db94011d3 83
sahilmgandhi 18:6a4db94011d3 84
sahilmgandhi 18:6a4db94011d3 85 /** @brief Function for read by twi_master.
sahilmgandhi 18:6a4db94011d3 86 */
sahilmgandhi 18:6a4db94011d3 87 static bool twi_master_read(uint8_t * data, uint8_t data_length, bool issue_stop_condition, NRF_TWI_Type* twi)
sahilmgandhi 18:6a4db94011d3 88 {
sahilmgandhi 18:6a4db94011d3 89 uint32_t timeout = MAX_TIMEOUT_LOOPS; /* max loops to wait for RXDREADY event*/
sahilmgandhi 18:6a4db94011d3 90
sahilmgandhi 18:6a4db94011d3 91 if (data_length == 0)
sahilmgandhi 18:6a4db94011d3 92 {
sahilmgandhi 18:6a4db94011d3 93 /* Return false for requesting data of size 0 */
sahilmgandhi 18:6a4db94011d3 94 return false;
sahilmgandhi 18:6a4db94011d3 95 }
sahilmgandhi 18:6a4db94011d3 96 else if (data_length == 1)
sahilmgandhi 18:6a4db94011d3 97 {
sahilmgandhi 18:6a4db94011d3 98 NRF_PPI->CH[0].TEP = (uint32_t)&twi->TASKS_STOP;
sahilmgandhi 18:6a4db94011d3 99 }
sahilmgandhi 18:6a4db94011d3 100 else
sahilmgandhi 18:6a4db94011d3 101 {
sahilmgandhi 18:6a4db94011d3 102 NRF_PPI->CH[0].TEP = (uint32_t)&twi->TASKS_SUSPEND;
sahilmgandhi 18:6a4db94011d3 103 }
sahilmgandhi 18:6a4db94011d3 104
sahilmgandhi 18:6a4db94011d3 105 NRF_PPI->CHENSET = PPI_CHENSET_CH0_Msk;
sahilmgandhi 18:6a4db94011d3 106 twi->EVENTS_RXDREADY = 0;
sahilmgandhi 18:6a4db94011d3 107 twi->TASKS_STARTRX = 1;
sahilmgandhi 18:6a4db94011d3 108
sahilmgandhi 18:6a4db94011d3 109 /** @snippet [TWI HW master read] */
sahilmgandhi 18:6a4db94011d3 110 while (true)
sahilmgandhi 18:6a4db94011d3 111 {
sahilmgandhi 18:6a4db94011d3 112 while (twi->EVENTS_RXDREADY == 0 && NRF_TWI1->EVENTS_ERROR == 0 && (--timeout))
sahilmgandhi 18:6a4db94011d3 113 {
sahilmgandhi 18:6a4db94011d3 114 // Do nothing.
sahilmgandhi 18:6a4db94011d3 115 }
sahilmgandhi 18:6a4db94011d3 116 twi->EVENTS_RXDREADY = 0;
sahilmgandhi 18:6a4db94011d3 117
sahilmgandhi 18:6a4db94011d3 118 if (timeout == 0 || twi->EVENTS_ERROR != 0)
sahilmgandhi 18:6a4db94011d3 119 {
sahilmgandhi 18:6a4db94011d3 120 // Recover the peripheral as indicated by PAN 56: "TWI: TWI module lock-up." found at
sahilmgandhi 18:6a4db94011d3 121 // Product Anomaly Notification document found at
sahilmgandhi 18:6a4db94011d3 122 // https://www.nordicsemi.com/eng/Products/Bluetooth-R-low-energy/nRF51822/#Downloads
sahilmgandhi 18:6a4db94011d3 123 twi->EVENTS_ERROR = 0;
sahilmgandhi 18:6a4db94011d3 124 twi->ENABLE = TWI_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos;
sahilmgandhi 18:6a4db94011d3 125 twi->POWER = 0;
sahilmgandhi 18:6a4db94011d3 126 nrf_delay_us(5);
sahilmgandhi 18:6a4db94011d3 127 twi->POWER = 1;
sahilmgandhi 18:6a4db94011d3 128 twi->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;
sahilmgandhi 18:6a4db94011d3 129
sahilmgandhi 18:6a4db94011d3 130 (void)twi_master_init_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 131
sahilmgandhi 18:6a4db94011d3 132 return false;
sahilmgandhi 18:6a4db94011d3 133 }
sahilmgandhi 18:6a4db94011d3 134
sahilmgandhi 18:6a4db94011d3 135 *data++ = NRF_TWI1->RXD;
sahilmgandhi 18:6a4db94011d3 136
sahilmgandhi 18:6a4db94011d3 137 /* Configure PPI to stop TWI master before we get last BB event */
sahilmgandhi 18:6a4db94011d3 138 if (--data_length == 1)
sahilmgandhi 18:6a4db94011d3 139 {
sahilmgandhi 18:6a4db94011d3 140 NRF_PPI->CH[0].TEP = (uint32_t)&NRF_TWI1->TASKS_STOP;
sahilmgandhi 18:6a4db94011d3 141 }
sahilmgandhi 18:6a4db94011d3 142
sahilmgandhi 18:6a4db94011d3 143 if (data_length == 0)
sahilmgandhi 18:6a4db94011d3 144 {
sahilmgandhi 18:6a4db94011d3 145 break;
sahilmgandhi 18:6a4db94011d3 146 }
sahilmgandhi 18:6a4db94011d3 147
sahilmgandhi 18:6a4db94011d3 148 // Recover the peripheral as indicated by PAN 56: "TWI: TWI module lock-up." found at
sahilmgandhi 18:6a4db94011d3 149 // Product Anomaly Notification document found at
sahilmgandhi 18:6a4db94011d3 150 // https://www.nordicsemi.com/eng/Products/Bluetooth-R-low-energy/nRF51822/#Downloads
sahilmgandhi 18:6a4db94011d3 151 nrf_delay_us(20);
sahilmgandhi 18:6a4db94011d3 152 twi->TASKS_RESUME = 1;
sahilmgandhi 18:6a4db94011d3 153 }
sahilmgandhi 18:6a4db94011d3 154 /** @snippet [TWI HW master read] */
sahilmgandhi 18:6a4db94011d3 155
sahilmgandhi 18:6a4db94011d3 156 /* Wait until stop sequence is sent */
sahilmgandhi 18:6a4db94011d3 157 while(twi->EVENTS_STOPPED == 0)
sahilmgandhi 18:6a4db94011d3 158 {
sahilmgandhi 18:6a4db94011d3 159 // Do nothing.
sahilmgandhi 18:6a4db94011d3 160 }
sahilmgandhi 18:6a4db94011d3 161 twi->EVENTS_STOPPED = 0;
sahilmgandhi 18:6a4db94011d3 162
sahilmgandhi 18:6a4db94011d3 163 NRF_PPI->CHENCLR = PPI_CHENCLR_CH0_Msk;
sahilmgandhi 18:6a4db94011d3 164 return true;
sahilmgandhi 18:6a4db94011d3 165 }
sahilmgandhi 18:6a4db94011d3 166
sahilmgandhi 18:6a4db94011d3 167
sahilmgandhi 18:6a4db94011d3 168 /**
sahilmgandhi 18:6a4db94011d3 169 * @brief Function for detecting stuck slaves (SDA = 0 and SCL = 1) and tries to clear the bus.
sahilmgandhi 18:6a4db94011d3 170 *
sahilmgandhi 18:6a4db94011d3 171 * @return
sahilmgandhi 18:6a4db94011d3 172 * @retval false Bus is stuck.
sahilmgandhi 18:6a4db94011d3 173 * @retval true Bus is clear.
sahilmgandhi 18:6a4db94011d3 174 */
sahilmgandhi 18:6a4db94011d3 175 static bool twi_master_clear_bus(NRF_TWI_Type* twi)
sahilmgandhi 18:6a4db94011d3 176 {
sahilmgandhi 18:6a4db94011d3 177 uint32_t twi_state;
sahilmgandhi 18:6a4db94011d3 178 bool bus_clear;
sahilmgandhi 18:6a4db94011d3 179 uint32_t clk_pin_config;
sahilmgandhi 18:6a4db94011d3 180 uint32_t data_pin_config;
sahilmgandhi 18:6a4db94011d3 181
sahilmgandhi 18:6a4db94011d3 182 // Save and disable TWI hardware so software can take control over the pins.
sahilmgandhi 18:6a4db94011d3 183 twi_state = twi->ENABLE;
sahilmgandhi 18:6a4db94011d3 184 twi->ENABLE = TWI_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos;
sahilmgandhi 18:6a4db94011d3 185
sahilmgandhi 18:6a4db94011d3 186 clk_pin_config = \
sahilmgandhi 18:6a4db94011d3 187 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER];
sahilmgandhi 18:6a4db94011d3 188 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER] = \
sahilmgandhi 18:6a4db94011d3 189 (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) \
sahilmgandhi 18:6a4db94011d3 190 | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) \
sahilmgandhi 18:6a4db94011d3 191 | (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos) \
sahilmgandhi 18:6a4db94011d3 192 | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) \
sahilmgandhi 18:6a4db94011d3 193 | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);
sahilmgandhi 18:6a4db94011d3 194
sahilmgandhi 18:6a4db94011d3 195 data_pin_config = \
sahilmgandhi 18:6a4db94011d3 196 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_DATA_PIN_NUMBER];
sahilmgandhi 18:6a4db94011d3 197 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_DATA_PIN_NUMBER] = \
sahilmgandhi 18:6a4db94011d3 198 (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) \
sahilmgandhi 18:6a4db94011d3 199 | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) \
sahilmgandhi 18:6a4db94011d3 200 | (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos) \
sahilmgandhi 18:6a4db94011d3 201 | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) \
sahilmgandhi 18:6a4db94011d3 202 | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);
sahilmgandhi 18:6a4db94011d3 203
sahilmgandhi 18:6a4db94011d3 204 TWI_SDA_HIGH();
sahilmgandhi 18:6a4db94011d3 205 TWI_SCL_HIGH();
sahilmgandhi 18:6a4db94011d3 206 TWI_DELAY();
sahilmgandhi 18:6a4db94011d3 207
sahilmgandhi 18:6a4db94011d3 208 if ((TWI_SDA_READ() == 1) && (TWI_SCL_READ() == 1))
sahilmgandhi 18:6a4db94011d3 209 {
sahilmgandhi 18:6a4db94011d3 210 bus_clear = true;
sahilmgandhi 18:6a4db94011d3 211 }
sahilmgandhi 18:6a4db94011d3 212 else
sahilmgandhi 18:6a4db94011d3 213 {
sahilmgandhi 18:6a4db94011d3 214 uint_fast8_t i;
sahilmgandhi 18:6a4db94011d3 215 bus_clear = false;
sahilmgandhi 18:6a4db94011d3 216
sahilmgandhi 18:6a4db94011d3 217 // Clock max 18 pulses worst case scenario(9 for master to send the rest of command and 9
sahilmgandhi 18:6a4db94011d3 218 // for slave to respond) to SCL line and wait for SDA come high.
sahilmgandhi 18:6a4db94011d3 219 for (i=18; i--;)
sahilmgandhi 18:6a4db94011d3 220 {
sahilmgandhi 18:6a4db94011d3 221 TWI_SCL_LOW();
sahilmgandhi 18:6a4db94011d3 222 TWI_DELAY();
sahilmgandhi 18:6a4db94011d3 223 TWI_SCL_HIGH();
sahilmgandhi 18:6a4db94011d3 224 TWI_DELAY();
sahilmgandhi 18:6a4db94011d3 225
sahilmgandhi 18:6a4db94011d3 226 if (TWI_SDA_READ() == 1)
sahilmgandhi 18:6a4db94011d3 227 {
sahilmgandhi 18:6a4db94011d3 228 bus_clear = true;
sahilmgandhi 18:6a4db94011d3 229 break;
sahilmgandhi 18:6a4db94011d3 230 }
sahilmgandhi 18:6a4db94011d3 231 }
sahilmgandhi 18:6a4db94011d3 232 }
sahilmgandhi 18:6a4db94011d3 233
sahilmgandhi 18:6a4db94011d3 234 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER] = clk_pin_config;
sahilmgandhi 18:6a4db94011d3 235 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_DATA_PIN_NUMBER] = data_pin_config;
sahilmgandhi 18:6a4db94011d3 236
sahilmgandhi 18:6a4db94011d3 237 twi->ENABLE = twi_state;
sahilmgandhi 18:6a4db94011d3 238
sahilmgandhi 18:6a4db94011d3 239 return bus_clear;
sahilmgandhi 18:6a4db94011d3 240 }
sahilmgandhi 18:6a4db94011d3 241
sahilmgandhi 18:6a4db94011d3 242
sahilmgandhi 18:6a4db94011d3 243 /** @brief Function for initializing the twi_master.
sahilmgandhi 18:6a4db94011d3 244 */
sahilmgandhi 18:6a4db94011d3 245 bool twi_master_init_and_clear(NRF_TWI_Type* twi)
sahilmgandhi 18:6a4db94011d3 246 {
sahilmgandhi 18:6a4db94011d3 247 /* To secure correct signal levels on the pins used by the TWI
sahilmgandhi 18:6a4db94011d3 248 master when the system is in OFF mode, and when the TWI master is
sahilmgandhi 18:6a4db94011d3 249 disabled, these pins must be configured in the GPIO peripheral.
sahilmgandhi 18:6a4db94011d3 250 */
sahilmgandhi 18:6a4db94011d3 251 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER] = \
sahilmgandhi 18:6a4db94011d3 252 (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) \
sahilmgandhi 18:6a4db94011d3 253 | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) \
sahilmgandhi 18:6a4db94011d3 254 | (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos) \
sahilmgandhi 18:6a4db94011d3 255 | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) \
sahilmgandhi 18:6a4db94011d3 256 | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
sahilmgandhi 18:6a4db94011d3 257
sahilmgandhi 18:6a4db94011d3 258 NRF_GPIO->PIN_CNF[TWI_MASTER_CONFIG_DATA_PIN_NUMBER] = \
sahilmgandhi 18:6a4db94011d3 259 (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) \
sahilmgandhi 18:6a4db94011d3 260 | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) \
sahilmgandhi 18:6a4db94011d3 261 | (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos) \
sahilmgandhi 18:6a4db94011d3 262 | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) \
sahilmgandhi 18:6a4db94011d3 263 | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
sahilmgandhi 18:6a4db94011d3 264
sahilmgandhi 18:6a4db94011d3 265 twi->EVENTS_RXDREADY = 0;
sahilmgandhi 18:6a4db94011d3 266 twi->EVENTS_TXDSENT = 0;
sahilmgandhi 18:6a4db94011d3 267 twi->PSELSCL = TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER;
sahilmgandhi 18:6a4db94011d3 268 twi->PSELSDA = TWI_MASTER_CONFIG_DATA_PIN_NUMBER;
sahilmgandhi 18:6a4db94011d3 269 twi->FREQUENCY = TWI_FREQUENCY_FREQUENCY_K100 << TWI_FREQUENCY_FREQUENCY_Pos;
sahilmgandhi 18:6a4db94011d3 270 NRF_PPI->CH[0].EEP = (uint32_t)&twi->EVENTS_BB;
sahilmgandhi 18:6a4db94011d3 271 NRF_PPI->CH[0].TEP = (uint32_t)&twi->TASKS_SUSPEND;
sahilmgandhi 18:6a4db94011d3 272 NRF_PPI->CHENCLR = PPI_CHENCLR_CH0_Msk;
sahilmgandhi 18:6a4db94011d3 273 twi->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;
sahilmgandhi 18:6a4db94011d3 274
sahilmgandhi 18:6a4db94011d3 275 return twi_master_clear_bus(twi);
sahilmgandhi 18:6a4db94011d3 276 }
sahilmgandhi 18:6a4db94011d3 277
sahilmgandhi 18:6a4db94011d3 278
sahilmgandhi 18:6a4db94011d3 279 /** @brief Function for transfer by twi_master.
sahilmgandhi 18:6a4db94011d3 280 */
sahilmgandhi 18:6a4db94011d3 281 bool twi_master_transfer(uint8_t address,
sahilmgandhi 18:6a4db94011d3 282 uint8_t * data,
sahilmgandhi 18:6a4db94011d3 283 uint8_t data_length,
sahilmgandhi 18:6a4db94011d3 284 bool issue_stop_condition,
sahilmgandhi 18:6a4db94011d3 285 NRF_TWI_Type* twi)
sahilmgandhi 18:6a4db94011d3 286 {
sahilmgandhi 18:6a4db94011d3 287 bool transfer_succeeded = false;
sahilmgandhi 18:6a4db94011d3 288 if (data_length > 0 && twi_master_clear_bus(twi))
sahilmgandhi 18:6a4db94011d3 289 {
sahilmgandhi 18:6a4db94011d3 290 twi->ADDRESS = (address >> 1);
sahilmgandhi 18:6a4db94011d3 291
sahilmgandhi 18:6a4db94011d3 292 if ((address & TWI_READ_BIT))
sahilmgandhi 18:6a4db94011d3 293 {
sahilmgandhi 18:6a4db94011d3 294 transfer_succeeded = twi_master_read(data, data_length, issue_stop_condition, twi);
sahilmgandhi 18:6a4db94011d3 295 }
sahilmgandhi 18:6a4db94011d3 296 else
sahilmgandhi 18:6a4db94011d3 297 {
sahilmgandhi 18:6a4db94011d3 298 transfer_succeeded = twi_master_write(data, data_length, issue_stop_condition, twi);
sahilmgandhi 18:6a4db94011d3 299 }
sahilmgandhi 18:6a4db94011d3 300 }
sahilmgandhi 18:6a4db94011d3 301 return transfer_succeeded;
sahilmgandhi 18:6a4db94011d3 302 }
sahilmgandhi 18:6a4db94011d3 303
sahilmgandhi 18:6a4db94011d3 304 /*lint --flb "Leave library region" */