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Rev | Author | Line No. | Line |
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22 | jlesech | 1 | #include <OneWire.h> |
2 | |||
3 | /* |
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4 | * DS2408 8-Channel Addressable Switch |
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5 | * |
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6 | * Writte by Glenn Trewitt, glenn at trewitt dot org |
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7 | * |
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8 | * Some notes about the DS2408: |
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9 | * - Unlike most input/output ports, the DS2408 doesn't have mode bits to |
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10 | * set whether the pins are input or output. If you issue a read command, |
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11 | * they're inputs. If you write to them, they're outputs. |
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12 | * - For reading from a switch, you should use 10K pull-up resisters. |
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13 | */ |
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14 | |||
15 | void PrintBytes(uint8_t* addr, uint8_t count, bool newline=0) { |
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16 | for (uint8_t i = 0; i < count; i++) { |
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17 | Serial.print(addr[i]>>4, HEX); |
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18 | Serial.print(addr[i]&0x0f, HEX); |
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19 | } |
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20 | if (newline) |
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21 | Serial.println(); |
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22 | } |
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23 | |||
24 | void ReadAndReport(OneWire* net, uint8_t* addr) { |
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25 | Serial.print(" Reading DS2408 "); |
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26 | PrintBytes(addr, 8); |
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27 | Serial.println(); |
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28 | |||
29 | uint8_t buf[13]; // Put everything in the buffer so we can compute CRC easily. |
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30 | buf[0] = 0xF0; // Read PIO Registers |
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31 | buf[1] = 0x88; // LSB address |
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32 | buf[2] = 0x00; // MSB address |
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33 | net->write_bytes(buf, 3); |
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34 | net->read_bytes(buf+3, 10); // 3 cmd bytes, 6 data bytes, 2 0xFF, 2 CRC16 |
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35 | net->reset(); |
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36 | |||
37 | if (!OneWire::check_crc16(buf, 11, &buf[11])) { |
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38 | Serial.print("CRC failure in DS2408 at "); |
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39 | PrintBytes(addr, 8, true); |
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40 | return; |
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41 | } |
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42 | Serial.print(" DS2408 data = "); |
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43 | // First 3 bytes contain command, register address. |
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44 | Serial.println(buf[3], BIN); |
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45 | } |
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46 | |||
47 | OneWire net(10); // on pin 10 |
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48 | |||
49 | void setup(void) { |
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50 | Serial.begin(9600); |
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51 | } |
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52 | |||
53 | void loop(void) { |
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54 | byte i; |
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55 | byte present = 0; |
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56 | byte addr[8]; |
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57 | |||
58 | if (!net.search(addr)) { |
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59 | Serial.print("No more addresses.\n"); |
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60 | net.reset_search(); |
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61 | delay(1000); |
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62 | return; |
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63 | } |
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64 | |||
65 | if (OneWire::crc8(addr, 7) != addr[7]) { |
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66 | Serial.print("CRC is not valid!\n"); |
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67 | return; |
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68 | } |
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69 | |||
70 | if (addr[0] != 0x29) { |
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71 | PrintBytes(addr, 8); |
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72 | Serial.print(" is not a DS2408.\n"); |
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73 | return; |
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74 | } |
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75 | |||
76 | ReadAndReport(&net, addr); |
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77 | } |