--- title: Interface Protocols description: published: true date: 2021-07-29T23:08:51.046Z tags: editor: markdown dateCreated: 2021-07-29T18:45:18.652Z --- # Interface Protocols > This information is intended for Advanced users ,a typical user does not need to have an understanding of the protocols used by the Interfaces in order to use Speeduino. {.is-warning} Speeduino can be interfaced to via several ways. 1. USB 2. Secondary Serial 3. Canbus (MCU dependent) ## 1. USB This is the primary interface and the way in which TunerStudio connects to Speeduino in order to program/configure its settings. Only a single device can communicate with Speeduino via the USB at a time, this is usually a laptop or other computer running the TunerStudio Application software. It is also possible to use this interface with other devices if the correct communication protocol is used. Great care must be taken as it is possible to corrupt the configuration of your Speeduino MCU such that it no longer functions correctly or at all! > It is highly recommended to connect Dashes,Dataloggers and other Third party devices via the Secondary Serial interface or Canbus(if available) {.is-warning} ### The Primary Protocol The Speeduino Primary serial protocol uses a request/response method, in that untill it recieves the correct set of commands it will not transmit data out.You must not send additional commands until the current one has been actioned. All data is little-endian. (Low byte first.) Data is sent in binary format and there is no conversion to text.Commands are case sensitive. ### The Commands #### 'a' Command This Command is for legacy use only. It returns the current realtime data. The data value list speeduino replies with can be seen below , along with their function.ONLY the data value is sent NOT its order number or description. The format to send is 'a' , '0' , '6' Speeduino replies with 1. highByte(currentStatus.secl) 2. lowByte(currentStatus.secl) 3. highByte(currentStatus.PW1) 4. lowByte(currentStatus.PW1) 5. highByte(currentStatus.PW2) 6. lowByte(currentStatus.PW2) 7. highByte(currentStatus.RPM) 8. lowByte(currentStatus.RPM) 9. highByte(currentStatus.advance * 10) 10. lowByte(currentStatus.advance * 10) 11. currentStatus.nSquirts); 12. currentStatus.engine); 13. currentStatus.afrTarget); 14. currentStatus.afrTarget); // send twice so afrtgt1 == afrtgt2 15. (99) // send dummy data as we don't have wbo2_en1 16. (99) // send dummy data as we don't have wbo2_en2 17. highByte(currentStatus.baro * 10) 18. lowByte(currentStatus.baro * 10) 19. highByte(currentStatus.MAP * 10) 20. lowByte(currentStatus.MAP * 10) 21. highByte(currentStatus.IAT * 10) 22. lowByte(currentStatus.IAT * 10) 23. highByte(currentStatus.coolant * 10) 24. lowByte(currentStatus.coolant * 10) 25. highByte(currentStatus.TPS * 10) 26. lowByte(currentStatus.TPS * 10) 27. highByte(currentStatus.battery10) 28. lowByte(currentStatus.battery10) 29. highByte(currentStatus.O2) 30. lowByte(currentStatus.O2) 31. highByte(currentStatus.O2_2) 32. lowByte(currentStatus.O2_2) 33. (99) // blank data for knock 34. (99) // blank data for knock 35. highByte(currentStatus.egoCorrection * 10) // egocor1 36. lowByte(currentStatus.egoCorrection * 10) // egocor1 37. highByte(currentStatus.egoCorrection * 10) // egocor2 38. lowByte(currentStatus.egoCorrection * 10) // egocor2 39. highByte(currentStatus.iatCorrection * 10) // aircor 40. lowByte(currentStatus.iatCorrection * 10) // aircor 41. highByte(currentStatus.wueCorrection * 10) // warmcor 42. lowByte(currentStatus.wueCorrection * 10) // warmcor 43. (99) // blank data for accelEnrich 44. (99) // blank data for accelEnrich 45. (99) // blank data for tpsFuelCut 46. (99) // blank data for tpsFuelCut 47. (99) // blank data for baroCorrection 48. (99) // blank data for baroCorrection 49. highByte(currentStatus.corrections * 10) // gammaEnrich 50. lowByte(currentStatus.corrections * 10) // gammaEnrich 51. highByte(currentStatus.VE * 10) // ve1 52. lowByte(currentStatus.VE * 10) // ve1 53. highByte(currentStatus.VE2 * 10) // ve2 54. lowByte(currentStatus.VE2 * 10) // ve2 55. (99) // blank data for iacstep 56. (99) // blank data for iacstep 57. (99) // blank data for cold_adv_deg 58. (99) // blank data for cold_adv_deg 59. highByte(currentStatus.tpsDOT * 10) // TPSdot 60. lowByte(currentStatus.tpsDOT * 10) // TPSdot 61. highByte(currentStatus.mapDOT * 10) // MAPdot 62. lowByte(currentStatus.mapDOT * 10) // MAPdot 63. highByte(currentStatus.dwell * 10) // dwell 64. lowByte(currentStatus.dwell * 10) // dwell 65. (99) // blank data for MAF 66. (99) // blank data for MAF 67. (currentStatus.fuelLoad*10) // fuelload 68. (99) // blank data for fuelcor 69. (99) // blank data for fuelcor 70. (99) // blank data for portStatus 71. highByte(currentStatus.advance1 * 10) 72. lowByte(currentStatus.advance1 * 10) 73. highByte(currentStatus.advance2 * 10) 74. lowByte(currentStatus.advance2 * 10) 75. to 114. (99) // bytes 75 to 114 blank data to fill buffer #### 'A' Command This returns all the current realtime data(120 bytes 29/07/2021). The data value list speeduino replies with can be seen below , along with their function.ONLY the data value is sent NOT its order number or description. The Format to send is 'A' Speeduino replies with 0. currentStatus.secl //secl is simply a counter that increments each second. Used to track unexpected resets (Which will reset this count to 0) 1. currentStatus.status1 //status1 Bitfield 2. currentStatus.engine //Engine Status Bitfield 3. currentStatus.syncLossCounter 4. lowByte(currentStatus.MAP) 5. highByte(currentStatus.MAP) 6. (byte)(currentStatus.IAT + CALIBRATION_TEMPERATURE_OFFSET) //mat 7. (byte)(currentStatus.coolant + CALIBRATION_TEMPERATURE_OFFSET) //Coolant ADC 8. currentStatus.batCorrection //Battery voltage correction (%) 9. currentStatus.battery10 //battery voltage 10. currentStatus.O2 //O2 11. currentStatus.egoCorrection //Exhaust gas correction (%) 12. currentStatus.iatCorrection //Air temperature Correction (%) 13. currentStatus.wueCorrection //Warmup enrichment (%) 14. lowByte(currentStatus.RPM) //rpm HB 15. highByte(currentStatus.RPM) //rpm LB 16. (byte)(currentStatus.AEamount >> 1) //TPS acceleration enrichment (%) divided by 2 (Can exceed 255) 17. lowByte(currentStatus.corrections) //Total GammaE (%) 18. highByte(currentStatus.corrections) //Total GammaE (%) 19. currentStatus.VE1 //VE 1 (%) 20. currentStatus.VE2 //VE 2 (%) 21. currentStatus.afrTarget 22. currentStatus.tpsDOT //TPS DOT 23. currentStatus.advance 24. currentStatus.TPS // TPS (0% to 100%) 25. lowByte(currentStatus.loopsPerSecond) 26. highByte(currentStatus.loopsPerSecond) 27. lowByte(currentStatus.freeRAM) 28. highByte(currentStatus.freeRAM) 29. (byte)(currentStatus.boostTarget >> 1 //Divide boost target by 2 to fit in a byte 30. (byte)(currentStatus.boostDuty / 100) 31. currentStatus.spark //Spark related bitfield 32. lowByte(currentStatus.rpmDOT) // rpmDOT must be sent as a signed integer 33. highByte(currentStatus.rpmDOT) 34. currentStatus.ethanolPct // Flex sensor value (or 0 if not used) 35. currentStatus.flexCorrection // Flex fuel correction (% above or below 100) 36. currentStatus.flexIgnCorrection //Ignition correction (Increased degrees of advance) for flex fuel 37. currentStatus.idleLoad 38. currentStatus.testOutputs 39. currentStatus.O2_2 //O2 40. currentStatus.baro //Barometer value 41. lowByte(currentStatus.canin[0]) 42. highByte(currentStatus.canin[0]) 43. lowByte(currentStatus.canin[1]) 44. highByte(currentStatus.canin[1]) 45. lowByte(currentStatus.canin[2]) 46. highByte(currentStatus.canin[2]) 47. lowByte(currentStatus.canin[3]) 48. highByte(currentStatus.canin[3]) 49. lowByte(currentStatus.canin[4]) 50. highByte(currentStatus.canin[4]) 51. lowByte(currentStatus.canin[5]) 52. highByte(currentStatus.canin[5]) 53. lowByte(currentStatus.canin[6]) 54. highByte(currentStatus.canin[6]) 55. lowByte(currentStatus.canin[7]) 56. highByte(currentStatus.canin[7]) 57. lowByte(currentStatus.canin[8]) 58. highByte(currentStatus.canin[8]) 59. lowByte(currentStatus.canin[9]) 60. highByte(currentStatus.canin[9]) 61. lowByte(currentStatus.canin[10]) 62. highByte(currentStatus.canin[10]) 63. lowByte(currentStatus.canin[11]) 64. highByte(currentStatus.canin[11]) 65. lowByte(currentStatus.canin[12]) 66. highByte(currentStatus.canin[12]) 67. lowByte(currentStatus.canin[13]) 68. highByte(currentStatus.canin[13]) 69. lowByte(currentStatus.canin[14]) 70. highByte(currentStatus.canin[14]) 71. lowByte(currentStatus.canin[15]) 72. highByte(currentStatus.canin[15]) 73. currentStatus.tpsADC 74. getNextError() 75. lowByte(currentStatus.PW1) //Pulsewidth 1 multiplied by 10 in ms. Have to convert from uS to mS. 76. highByte(currentStatus.PW1) //Pulsewidth 1 multiplied by 10 in ms. Have to convert from uS to mS. 77. lowByte(currentStatus.PW2) //Pulsewidth 2 multiplied by 10 in ms. Have to convert from uS to mS. 78. highByte(currentStatus.PW2) //Pulsewidth 2 multiplied by 10 in ms. Have to convert from uS to mS. 79. lowByte(currentStatus.PW3) //Pulsewidth 3 multiplied by 10 in ms. Have to convert from uS to mS. 80. highByte(currentStatus.PW3) //Pulsewidth 3 multiplied by 10 in ms. Have to convert from uS to mS. 81. lowByte(currentStatus.PW4) //Pulsewidth 4 multiplied by 10 in ms. Have to convert from uS to mS. 82. highByte(currentStatus.PW4) //Pulsewidth 4 multiplied by 10 in ms. Have to convert from uS to mS. 83. currentStatus.status3 84. currentStatus.engineProtectStatus 85. lowByte(currentStatus.fuelLoad) 86. highByte(currentStatus.fuelLoad) 87. lowByte(currentStatus.ignLoad) 88. highByte(currentStatus.ignLoad) 89. lowByte(currentStatus.dwell) 90. highByte(currentStatus.dwell) 91. currentStatus.CLIdleTarget 92. currentStatus.mapDOT 93. lowByte(currentStatus.vvt1Angle) //2 bytes for vvt1Angle 94. highByte(currentStatus.vvt1Angle) 95. currentStatus.vvt1TargetAngle 96. (byte)(currentStatus.vvt1Duty) 97. lowByte(currentStatus.flexBoostCorrection) 98. highByte(currentStatus.flexBoostCorrection) 99. currentStatus.baroCorrection 100. currentStatus.VE //Current VE (%). Can be equal to VE1 or VE2 or a calculated value from both of them 101. currentStatus.ASEValue //Current ASE (%) 102. lowByte(currentStatus.vss) 103. highByte(currentStatus.vss) 104. currentStatus.gear 105. currentStatus.fuelPressure 106. currentStatus.oilPressure 107. currentStatus.wmiPW 108. currentStatus.status4 109. lowByte(currentStatus.vvt2Angle) 110. highByte(currentStatus.vvt2Angle) 111. currentStatus.vvt2TargetAngle 112. (byte)(currentStatus.vvt2Duty) 113. currentStatus.outputsStatus 114. (byte)(currentStatus.fuelTemp + CALIBRATION_TEMPERATURE_OFFSET) //Fuel temperature from flex sensor 115. currentStatus.fuelTempCorrection //Fuel temperature Correction (%) 116. currentStatus.advance1 //advance 1 (%) 117. currentStatus.advance2 //advance 2 (%) 118. currentStatus.TS_SD_Status //SD card status 119. lowByte(currentStatus.EMAP) 120. highByte(currentStatus.EMAP) #### 'b' Command New EEPROM burn command to only burn a single page at a time The Format to send is 'b' , '0' , '*' Where * is the config page number Speeduino response (none) #### 'B' Command This Burns the current configuration from RAM into EEPROM/non-volatile storage. The Format to send is 'B' Speeduino response (none) #### 'c' Command Send the current loops/sec value The Format to send is 'c' Speeduino response lowByte(currentStatus.loopsPerSecond) , highByte(currentStatus.loopsPerSecond) #### 'C' Command Test communications. This is used by Tunerstudio to see whether there is an ECU on a given serial port The Format to send is 'B' Speeduino response #### 'd' Command Send a CRC32 hash of a given page The Format to send is 'd' , '0' , '*' where * is the value to calc the hash of. The response is 3 bytes calculated as follows. CRC32_val = calculateCRC32( * ) ((CRC32_val >> 24) & 255) ) byte 1 = ( ((CRC32_val >> 16) & 255) ) byte 2 = ( ((CRC32_val >> 8) & 255) ) byte 3 = ( (CRC32_val & 255) ) Speeduino response byte 1 , byte 2 , byte 3 #### 'E' Command Command button commands. Commands are built as cmdCombined = word(cmdGroup, cmdValue). this is the current(29/07/2021) list of valid cmdCombined command values. TS_CMD_TEST_DSBL 256 TS_CMD_TEST_ENBL 257 TS_CMD_INJ1_ON 513 TS_CMD_INJ1_OFF 514 TS_CMD_INJ1_50PC 515 TS_CMD_INJ2_ON 516 TS_CMD_INJ2_OFF 517 TS_CMD_INJ2_50PC 518 TS_CMD_INJ3_ON 519 TS_CMD_INJ3_OFF 520 TS_CMD_INJ3_50PC 521 TS_CMD_INJ4_ON 522 TS_CMD_INJ4_OFF 523 TS_CMD_INJ4_50PC 524 TS_CMD_INJ5_ON 525 TS_CMD_INJ5_OFF 526 TS_CMD_INJ5_50PC 527 TS_CMD_INJ6_ON 528 TS_CMD_INJ6_OFF 529 TS_CMD_INJ6_50PC 530 TS_CMD_INJ7_ON 531 TS_CMD_INJ7_OFF 532 TS_CMD_INJ7_50PC 533 TS_CMD_INJ8_ON 534 TS_CMD_INJ8_OFF 535 TS_CMD_INJ8_50PC 536 TS_CMD_IGN1_ON 769 TS_CMD_IGN1_OFF 770 TS_CMD_IGN1_50PC 771 TS_CMD_IGN2_ON 772 TS_CMD_IGN2_OFF 773 TS_CMD_IGN2_50PC 774 TS_CMD_IGN3_ON 775 TS_CMD_IGN3_OFF 776 TS_CMD_IGN3_50PC 777 TS_CMD_IGN4_ON 778 TS_CMD_IGN4_OFF 779 TS_CMD_IGN4_50PC 780 TS_CMD_IGN5_ON 781 TS_CMD_IGN5_OFF 782 TS_CMD_IGN5_50PC 783 TS_CMD_IGN6_ON 784 TS_CMD_IGN6_OFF 785 TS_CMD_IGN6_50PC 786 TS_CMD_IGN7_ON 787 TS_CMD_IGN7_OFF 788 TS_CMD_IGN7_50PC 789 TS_CMD_IGN8_ON 790 TS_CMD_IGN8_OFF 791 TS_CMD_IGN8_50PC 792 TS_CMD_STM32_REBOOT 12800 TS_CMD_STM32_BOOTLOADER 12801 TS_CMD_VSS_60KMH 39168 //0x99x00 TS_CMD_VSS_RATIO1 39169 TS_CMD_VSS_RATIO2 39170 TS_CMD_VSS_RATIO3 39171 TS_CMD_VSS_RATIO4 39172 TS_CMD_VSS_RATIO5 39173 TS_CMD_VSS_RATIO6 39174 The Format to send is 'E' , cmdGroup , cmdValue eg for cmdtestspk1on send 'E' , '0x03' , '0x01' Speeduino response (none , hardware action only) #### 'F' Command send serial protocol version The Format to send is 'F' Speeduino response '0' , '0' , '1' NOTE these values are sent in ASCII. #### 'h' Command Stop the tooth logger This reconnects the crank and cam input interrupts back to the normal input trigger code. The Format to send is 'h' Speeduino response (none) #### 'H' Command Start the tooth logger This disconnects the crank and cam input interrupts from their normal input trigger code and routes them to the tooth logger code.An acknowledge reply is made by speeduino. The Format to send is 'H' Speeduino response '1' #### 'j' Command Stop the composite logger This reconnects the crank and cam input interrupts back to the normal input trigger code. The Format to send is 'j' Speeduino response #### 'J' Command Start the composite logger This disconnects the crank and cam input interrupts from their normal input trigger code and routes them to the composite logger code.An acknowledge reply is made by speeduino. The Format to send is 'J' Speeduino response '1' #### 'L' Command List the contents of current page in human readable form You must set the current page prior to issuing this command to set the required page to be generated. the data structure is as follows. currentPage veMapPage: Serial.println(F("\nVE Map")); serial_print_3dtable(fuelTable); currentPage veSetPage: Serial.println(F("\nPg 2 Cfg")); // The following loop displays in human readable form of all byte values in config page 1 up to but not including the first array. serial_println_range((byte *)&configPage2, configPage2.wueValues); serial_print_space_delimited_array(configPage2.wueValues); // This displays all the byte values between the last array up to but not including the first unsigned int on config page 1 serial_println_range(_end_range_byte_address(configPage2.wueValues), (byte*)&configPage2.injAng); // The following loop displays four unsigned ints serial_println_range(configPage2.injAng, configPage2.injAng + _countof(configPage2.injAng)); // Following loop displays byte values between the unsigned ints serial_println_range(_end_range_byte_address(configPage2.injAng), (byte*)&configPage2.mapMax); Serial.println(configPage2.mapMax); // Following loop displays remaining byte values of the page serial_println_range(&configPage2.fpPrime, (byte *)&configPage2 + sizeof(configPage2)); break; currentPage ignMapPage: Serial.println(F("\nIgnition Map")); serial_print_3dtable(ignitionTable); currentPage ignSetPage: Serial.println(F("\nPg 4 Cfg")); Serial.println(configPage4.triggerAngle);// configPage4.triggerAngle is an int so just display it without complication // Following loop displays byte values after that first int up to but not including the first array in config page 2 serial_println_range((byte*)&configPage4.FixAng, configPage4.taeBins); serial_print_space_delimited_array(configPage4.taeBins); serial_print_space_delimited_array(configPage4.taeValues); serial_print_space_delimited_array(configPage4.wueBins); Serial.println(configPage4.dwellLimit);// Little lonely byte stuck between two arrays. No complications just display it. serial_print_space_delimited_array(configPage4.dwellCorrectionValues); serial_println_range(_end_range_byte_address(configPage4.dwellCorrectionValues), (byte *)&configPage4 + sizeof(configPage4)); currentPage afrMapPage: Serial.println(F("\nAFR Map")); serial_print_3dtable(afrTable); break; currentPage afrSetPage: Serial.println(F("\nPg 6 Config")); serial_println_range((byte *)&configPage6, configPage6.voltageCorrectionBins); serial_print_space_delimited_array(configPage6.voltageCorrectionBins); serial_print_space_delimited_array(configPage6.injVoltageCorrectionValues); serial_print_space_delimited_array(configPage6.airDenBins); serial_print_space_delimited_array(configPage6.airDenRates); serial_println_range(_end_range_byte_address(configPage6.airDenRates), configPage6.iacCLValues); serial_print_space_delimited_array(configPage6.iacCLValues); serial_print_space_delimited_array(configPage6.iacOLStepVal); serial_print_space_delimited_array(configPage6.iacOLPWMVal); serial_print_space_delimited_array(configPage6.iacBins); serial_print_space_delimited_array(configPage6.iacCrankSteps); serial_print_space_delimited_array(configPage6.iacCrankDuty); serial_print_space_delimited_array(configPage6.iacCrankBins); // Following loop is for remaining byte value of page serial_println_range(_end_range_byte_address(configPage6.iacCrankBins), (byte *)&configPage6 + sizeof(configPage6)); break; currentPage boostvvtPage: Serial.println(F("\nBoost Map")); serial_print_3dtable(boostTable); Serial.println(F("\nVVT Map")); serial_print_3dtable(vvtTable); break; currentPage seqFuelPage: Serial.println(F("\nTrim 1 Table")); serial_print_3dtable(trim1Table); break; currentPage canbusPage: Serial.println(F("\nPage 9 Cfg")); serial_println_range((byte *)&configPage9, (byte *)&configPage9 + sizeof(configPage9)); break; currentPage fuelMap2Page: Serial.println(F("\n2nd Fuel Map")); serial_print_3dtable(fuelTable2); break; currentPage ignMap2Page: Serial.println(F("\n2nd Ignition Map")); serial_print_3dtable(ignitionTable2); break; currentPage warmupPage: N/A currentPage progOutsPage: N/A #### 'm' Command Send the current free memory The Format to send is 'm' Speeduino response 'lowByte(currentStatus.freeRAM)' , 'highByte(currentStatus.freeRAM)' #### 'M' Command #### 'N' Command Displays a new line. Like pushing enter in a text editor The Format to send is 'N' Speeduino response ' ' NOTE this is sent as plain text NOT ASCII #### 'p' Command Sets the current Page.This is the new foramt used by TunerStudio. 6 bytes are required: - 2 byte - Page identifier - 2 byte - offset - 2 byte - Length #### 'P' Command Sets the current page. This is a legacy function and is no longer used by TunerStudio. It is maintained for compatibility with other systems. The Format to send is 'P' , '*' Where * is the Page number to be selected. this MUST be sent in ASCII format Speeduino response (none) #### 'Q' Command Send the code version. The response is a 20 byte long ASCII converted string The Format to send is 'Q' Speeduino response 'speeduino 202104-dev' Above is an example reply, the actual reply will depend on what firmware is installed. #### 'r' Command This command has multiple functions, It requests specific data.This data may be realtime values or from RTC or SD card. #### 'S' Command send the code version. The response is a 20 byte long ASCII converted string The Format to send is 'S' Speeduino response 'Speeduino 2021.04-dev' Above is an example reply, the actual reply will depend on what firmware is installed. #### 't' Command receive new Calibration info. Command structure: "t", tble_idx , data array. #### 'T' Command Send 256 tooth log entries to Tuner Studios tooth logger 6 bytes required: 2 - Page identifier 2 - offset 2 - Length #### 'U' Command User wants to reset the Arduino (probably for FW update) #### 'V'Command send VE table and constants in binary #### 'w' Command #### 'W'Command receive new VE or constant 'W' , offset , newbyte #### 'z' Command Send the 256 tooth log entries to a terminal emulator #### '?' Command This will send out a human text readable string with details of the command characters and their functions. The Format to send is '?' Speeduino response ===Command Help=== All commands are single character and are concatenated with their parameters without spaces. Syntax: command , parameter1 , parameter2 , parameterN ===List of Commands=== A - Displays 31 bytes of currentStatus values in binary (live data) B - Burn current map and configPage values to eeprom C - Test COM port. Used by Tunerstudio to see whether an ECU is on a given serial port. Returns a binary number. N - Print new line. P - Set current page. Syntax: P , pageNumber R - Same as A command S - Display signature number Q - Same as S command V - Display map or configPage values in binary W - Set one byte in map or configPage. Expects binary parameters. Syntax: W+