1 | #define MPU6050 ((uint8_t) 0x68)
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2 |
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3 | void RCC_Configuration(void) {
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4 | /* GPIOB clock enable */
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5 | RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
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6 | /* I2C clock enable */
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7 | RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
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8 | }
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9 |
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10 |
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11 | void GPIO_Configuration(void) {
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12 | GPIO_InitTypeDef GPIO_InitStructure;
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13 |
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14 | /* I2C1 PB6 = SCL, PB7 = SDA Pin Configuration */
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15 | GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
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16 | GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
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17 | GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
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18 | GPIO_Init(GPIOB, &GPIO_InitStructure);
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19 | }
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20 |
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21 | void I2C_Configuration(void) {
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22 | I2C_InitTypeDef I2C_InitStructure;
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23 |
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24 | I2C_DeInit(I2C1);
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25 |
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26 | I2C_InitStructure.I2C_ClockSpeed = 400000; // 400kHz
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27 | I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
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28 | I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
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29 | I2C_InitStructure.I2C_OwnAddress1 = 0x00;
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30 | I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
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31 | I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
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32 | I2C_Init(I2C1, &I2C_InitStructure);
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33 |
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34 | I2C_Cmd(I2C1, ENABLE);
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35 | }
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36 |
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37 |
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38 | void I2C_start(I2C_TypeDef* I2Cx, uint8_t address, uint8_t direction) {
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39 | trace_puts("i2c start\n");
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40 | while (I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY));
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41 |
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42 | I2C_GenerateSTART(I2Cx, ENABLE);
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43 | while (!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));
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44 | I2C_Send7bitAddress(I2Cx, address, direction);
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45 |
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46 | if (direction == I2C_Direction_Transmitter) {
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47 | while (!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
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48 | }
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49 | else if (direction == I2C_Direction_Receiver) {
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50 | while (!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
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51 | }
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52 | }
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53 |
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54 | void I2C_write(I2C_TypeDef* I2Cx, uint8_t data) {
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55 | trace_puts("i2c write\n");
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56 | I2C_SendData(I2Cx, data);
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57 | while (!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
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58 | }
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59 |
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60 | uint8_t I2C_read_nack(I2C_TypeDef* I2Cx) {
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61 | trace_puts("i2c read nack\n");
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62 |
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63 | I2C_AcknowledgeConfig(I2Cx, DISABLE);
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64 | while ( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED) ) {
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65 | trace_printf("i2c read nack stuck\n");
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66 | }
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67 | uint8_t data = I2C_ReceiveData(I2Cx);
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68 |
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69 | return data;
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70 | }
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71 |
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72 | void I2C_stop(I2C_TypeDef* I2Cx) {
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73 | trace_puts("i2c stop\n");
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74 |
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75 | I2C_GenerateSTOP(I2Cx, ENABLE);
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76 |
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77 | // Wait until I2C stop condition is finished
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78 | while (I2C_GetFlagStatus(I2Cx, I2C_FLAG_STOPF));
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79 | }
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80 |
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81 | /* Single-Byte Read Sequence*/
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82 | uint8_t Read_Reg(uint8_t reg_adr) {
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83 | I2C_start(I2C1, MPU6050 << 1, I2C_Direction_Transmitter);
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84 | I2C_write(I2C1, reg_adr);
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85 | I2C_stop(I2C1);
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86 |
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87 | I2C_start(I2C1, MPU6050 << 1, I2C_Direction_Receiver);
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88 | uint8_t received_data = I2C_read_nack(I2C1);
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89 | I2C_stop(I2C1);
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90 | return received_data;
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91 | }
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92 |
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93 | int main(void) {
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94 | System_Clock_Setup();
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95 |
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96 | RCC_Configuration();
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97 | GPIO_Configuration();
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98 | I2C_Configuration();
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99 |
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100 | trace_puts("Hello\n");
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101 | Delay(1e5);
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102 | while (1) {
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103 | trace_puts("loop begin\n");
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104 |
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105 | uint8_t addr = Read_Reg(0x75);
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106 | trace_printf("addr: %i\n", addr);
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107 | Delay(1e4);
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108 | }
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109 | }
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