1 | ////////////////////////////////////////// TWI_M_start //////////////////////////////////////////
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2 |
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3 | /*
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4 | starting TWI with slave's address and choosing mode between MT and MR
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5 |
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6 | read_or_write=1: MR read_or_write=0: MT option is for first sending (initialization)
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7 |
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8 | returns TWI_M_START_FAILED_1, TWI_M_START_FAILED_2 or START_SUCCEED
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9 | */
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10 | int8_t TWI_M_start(uint8_t address, uint8_t read_or_write, uint8_t option)
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11 | {
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12 |
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13 | TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN); // enable interrupt flag, send start, enable TWI
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14 |
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15 | while( ! ( TWCR & (1 << TWINT) ) ); // wait for operation
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16 |
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17 | if( ( (TW_STATUS) != M_START ) && ( (TW_STATUS) != M_REPEADED_START ) ) // checking error
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18 | {
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19 |
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20 | TWI_M_stop();
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21 | return TWI_M_START_FAILED_1; // return error
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22 |
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23 | }
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24 |
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25 | TWDR = ( (address << 1) + read_or_write) | option; // choosing slave showing if MR or MT mode starts
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26 | //TWDR = (address) + read_or_write; // choosing slave showing if MR or MT mode starts
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27 | TWCR = (1 << TWINT) | (1 << TWEN); // TWINT bit has to be set for transmission
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28 |
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29 | while( ! ( TWCR & (1 << TWINT) ) ); // wait for operation
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30 |
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31 | //if( ( (TW_STATUS & 0b11111000) != MT_SLA_W_TRANS_ACK_REC ) && ( (TW_STATUS & 0b11111000) != MR_SLA_R_TRANS_ACK_REC ) ) // checking error // TWSR // 0x18 // 0x40
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32 | if( ( (TW_STATUS) != MT_SLA_W_TRANS_ACK_REC ) && ( (TW_STATUS) != MR_SLA_R_TRANS_ACK_REC ) )
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33 | {
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34 |
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35 | TWI_M_stop();
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36 | return TWI_M_START_FAILED_2;
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37 |
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38 | }
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39 |
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40 | return START_SUCCEED;
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41 |
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42 | }
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43 |
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44 | //$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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45 |
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46 |
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47 | ////////////////////////////////////////// TWI_M_write //////////////////////////////////////////
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48 |
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49 | /*
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50 | writes in TWI data register
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51 |
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52 | returns MT_DATA_TRAMS_FAILED or MT_DATA_TRANS_SUCCEED
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53 | */
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54 | int8_t TWI_M_write(uint8_t data)
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55 | {
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56 |
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57 | TWDR = data; // send data
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58 |
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59 | TWCR = (1 << TWINT) | (1 << TWEN); // TWINT bit has to be set for transmission
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60 |
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61 | while( ! ( TWCR & (1 << TWINT) ) ); // wait for operation
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62 |
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63 | if( ( (TW_STATUS) != MT_DATA_TRANS_ACK_RETURN ) && ( (TW_STATUS) != MT_DATA_TRANS_NACK_RETURN ) ) // checking error
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64 | {
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65 |
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66 | TWI_M_stop();
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67 | return MT_DATA_TRANS_FAILED;
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68 |
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69 | }
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70 |
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71 | return MT_DATA_TRANS_SUCCEED;
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72 |
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73 | }
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74 |
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75 | //$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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76 |
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77 |
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78 |
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79 |
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80 |
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81 | ////////////////////////////////////////// TWI_M_stop //////////////////////////////////////////
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82 |
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83 | /*
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84 | stops TWI
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85 |
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86 | no return
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87 | */
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88 | void TWI_M_stop()
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89 | {
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90 |
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91 | TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);
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92 |
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93 | }
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94 |
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95 | //$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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