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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | mjames | 1 | |
| 2 | |||
| 3 | #include "libTinyWB/tinyWB.h" |
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| 4 | |||
| 5 | #include "libSerial/serialCalls.H" |
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| 6 | |||
| 7 | #define CHARS_PER_FRAME 9 |
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| 8 | #define START_CODE 1 |
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| 9 | |||
| 10 | /// @brief time between character bursts |
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| 11 | static const uint32_t GAP_TIME_MS = 40; |
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| 12 | |||
| 13 | |||
| 14 | /// @brief Time of last reception of a character |
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| 15 | static uint32_t lastCharTime = 0; |
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| 16 | |||
| 17 | static uint8_t characterIndex = 0; |
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| 18 | |||
| 19 | /// @note Documentation from DIY-EFI |
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| 20 | /// Data Rate: 115200 baud |
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| 21 | /// Length: 8 bytes |
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| 22 | /// Data Format : |
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| 23 | /// byte0 = AFR*10 (so 148 = 14.8 AFR) |
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| 24 | /// byte1 = Temp in C of the sensor |
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| 25 | /// byte2-7 = not used |
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| 26 | /// The TinyWB is based on the SLCFree by 14point7 |
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| 3 | mjames | 27 | /// actually this document is wrong - below is the decode from using protocol analyser. |
| 28 | /// when the lambda sensor is not connected, the unit outputs something like 1,200 gap of 50mS and repeats# |
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| 2 | mjames | 29 | /// |
| 3 | mjames | 30 | /// when the lambda sensor is connected, the unit outputs this pattern |
| 2 | mjames | 31 | |
| 32 | //[0] 0.0000000000,1,, sync ? |
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| 33 | //[1] 0.0000867750,200,, afr |
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| 34 | //[2] 0.0001735250,41,, temperature |
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| 35 | //[3] 0.0002603000,2,, filler |
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| 36 | //[4] 0.0003471000,3,, filler |
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| 37 | //[5] 0.0004338750,4,, filler |
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| 38 | //[6] 0.0005206750,5,, filler |
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| 39 | //[7] 0.0006074500,6,, filler |
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| 40 | //[8] 0.0006942250,200,, afr again ? at byte 8. |
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| 41 | |||
| 42 | |||
| 43 | |||
| 44 | // store first two characters, ignore the rest |
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| 45 | static char afrCode = 0; |
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| 46 | static char tempCode = 0; |
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| 47 | |||
| 48 | char pollTinyWB(struct usart_ctl *instance, float *AFRvalue, float *temperature) |
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| 49 | { |
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| 50 | int valid = 0; |
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| 3 | mjames | 51 | // PollSerial returns non zero if characters are in the serial input buffer |
| 52 | while (PollSerial(instance)) |
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| 2 | mjames | 53 | { |
| 54 | // deal with time-based synchronisation - 8 byte bursts with gaps |
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| 55 | uint32_t now = HAL_GetTick(); |
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| 56 | if (now - lastCharTime > GAP_TIME_MS) |
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| 57 | { |
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| 58 | characterIndex = 0; |
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| 59 | } |
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| 60 | lastCharTime = now; |
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| 3 | mjames | 61 | // GetCharSerial is implemented as a blocking read from a USART : but because it is |
| 62 | // only called when PollSerial is true, it is never going to block. |
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| 2 | mjames | 63 | char c = GetCharSerial(instance); |
| 64 | if (characterIndex < CHARS_PER_FRAME) |
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| 65 | |||
| 66 | switch (characterIndex) |
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| 67 | { |
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| 68 | case 0: |
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| 69 | if (c != 1) |
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| 70 | goto fail; |
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| 71 | characterIndex++; |
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| 72 | break; |
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| 73 | // for characters 1 and 2 store in buffer |
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| 74 | case 1: |
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| 75 | afrCode = c; |
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| 76 | characterIndex++; |
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| 77 | break; |
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| 78 | case 2: |
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| 79 | tempCode = c; |
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| 80 | characterIndex++; |
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| 81 | break; |
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| 82 | |||
| 83 | case 3: |
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| 84 | case 4: |
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| 85 | case 5: |
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| 86 | case 6: |
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| 87 | case 7: |
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| 88 | if (c != characterIndex - 1) |
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| 89 | goto fail; |
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| 90 | characterIndex++; |
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| 91 | break; |
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| 92 | |||
| 93 | case CHARS_PER_FRAME - 1: |
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| 94 | *AFRvalue = afrCode / 10.0; |
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| 95 | *temperature = tempCode; |
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| 96 | valid = 1; // have valid readings |
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| 97 | |||
| 98 | fail: |
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| 99 | characterIndex = 0; |
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| 100 | break; |
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| 101 | } |
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| 102 | } |
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| 103 | |||
| 104 | return valid; |
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| 105 | } |