# Serial Interface ## Introduction Fenix Autopilot can be connected to a Laptop/PC via USB port. This provides access to all user functions available to calibrate compass and linear actuator. Also provides full capabilities to customize installation settings and pilot gain. ## Requirements * Serial Terminal shall be installed to Laptop/PC to communicate with Autopilot to use Serial Interface (eg. Arduino IDE, Putty) * [Checksum calculator](#checksum) * [$PMEC Message specification](#usdpemc-message) in this Guide. ### Checksum In order to generate $PEMC messages to be accepted by Fenix Autopilot, a checksum code shall be annexed after \* symbol. {% hint style="info" %} Serial I/F examples in this User Guide represent Checksum code as `xx`. To use these examples you should substitute `xx` by the calculated Checksum value. `Serial I/F Example: $PEMC,00*xx` `Serial I/F Valid Sentence: $PEMC,00*37` {% endhint %} In this link you will find an online Checksum calculator {% embed url="" %} {% embed url="" %} #### Set messages: 04 and 06 To keep same value of a parameter while changing others, omit any value while keeping the commas in place. {% hint style="info" %} To set Ki value while keeping Kp and Kd: $PEMC,06,,0.3,,,m\*xx {% endhint %} {% hint style="warning" %} Fenix V0.1 bug: Message 06, always include `m, M or A` deadband value or system will change to `M`. {% endhint %} ### $PEMC Message | Field | Value | Function | Additional Field | Sentence | | ----- | ----- | --------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------- | | 1 | 00 | Switch working mode from STAND BY to AUTO | N/A | $PEMC,00\*37 | | 1 | 01 | Change Current Rudder | [2: Change rate](#additional-field-change-rate) | $PEMC,01,r\*68 | | 1 | 02 | Change CTS (Current Target Steering) | [2: Change rate](#additional-field-change-rate) | $PEMC,02,i\*70 | | 1 | 03 | Get Installation Parameters | [2: Installation Parameters](#additional-field-installation-parameters) | $PEMC,03,2,45,5,S,2,-3.2,-32.9,10\*xx | | 1 | 04 | Set Installation Parameters | [2: Installation Parameters](#additional-field-installation-parameters) | $PEMC,04,2,40,4,S,3,4.1,33.9,9\*xx | | 1 | 05 | Get PID gain (incl. sample time and deadband) | [2: PID Gain](#additional-field-pid-gain) | $PEMC,05,2,0.01,0.5,100,A\*xx | | 1 | 06 | Set PID gain (inc. sample time and deadband) | [2: PID Gain](#additional-field-pid-gain) | $PEMC,06,3,0.11,0.7,100,m\*xx | | 1 | 07 | Get Autopilot information | [2: APinfo](#additional-field-apinfo) | $PEMC,07,S,12,35.60,30.02,2,-0.50\*65 | | 1 | 08 | Request information |

2: 'I' Request Installation Parameters (message $PEMC,03)

2: 'G' Request Gain (message $PEMC,05)

2: 'A' Request Autopilot info. (message $PEMC,07)

|

$PEMC,08,I*5A

$PEMC,08,G*54

$PEMC,08,A\*52

| | 1 | 09 | Enter/ Exit into IMU Calibration mode |

2:'-' Calibration of all sensors in sequence 2:'G' Gyroscope calibration only

2:'A' Accelerometer calibration only

2:'M' Magnetometer calibration only

|

$PEMC,09,-*xx

$PEMC,09,G*xx

$PEMC,09,A*xx

$PEMC,09,M*xx

| | 1 | 10 | Enter/ Exit Feedback Calibration mode | N/A | $PEMC,10\*36 | | 1 | 11 | Save values |

2: 'I' Save Installation and current Feedback Parameters

2: 'G' Save current PID Gain parameters

2: 'C' Save current IMU Offsets

2: 'R' Restore Inst.Param, Feedback and PID Gain to hardcoded values

|

$PEMC,11,I*52

$PEMC,11,G*5C

$PEMC,11,C*58

$PEMC,11,R*49

| | 1 | 12 | IMU Cal.Mode status | Cal.Mode values | $PEMC,12, | #### Additional Field: Change rate [![](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M1IFMsiQH0N5uEseRXb%2Fuploads%2FacmjKiNZvOmCvT3sdMR1%2Ffile.gif?alt=media)](https://emacua.fandom.com/wiki/System_Interfaces?action=edit\§ion=9) | Field | Value | Function | Additional Field | | ----- | ----- | ------------------------------------- | ---------------- | | n | 'i' | Increment Current by 1 Position Unit | N/A | | n | 'I' | Increment Current by 10 Position Unit | N/A | | n | 'r' | Reduce Current by 1 Position Unit | N/A | | n | 'R' | Reduce Current by 10 Position Uni | N/A | #### Additional Field: Installation Parameters [![](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M1IFMsiQH0N5uEseRXb%2Fuploads%2FfOfMRFSx9Pu5ReJekINY%2Ffile.gif?alt=media)](https://emacua.fandom.com/wiki/System_Interfaces?action=edit\§ion=10) | Field | Value | Function | Additional Field | | ----- | ------------ | ---------------------------- | ---------------- | | n | Integer | Centered Tiller Position | N/A | | n+1 | Positive Int | Maximum rudder angle | N/A | | n+2 | Positive Int | Average Cruise Speed | N/A | | n+3 | 'S' | Installation Side: Starboard | N/A | | n+3 | 'P' | Installation Side: Portboard | N/A | | n+4 | Positive Int | Rudder Damping | N/A | | n+5 | Float | Magnetic Variation | N/A | | n+6 | Float | Heading Alignment | N/A | | n+7 | Positive Int | Off course alarm angle | N/A | #### Additional Field: PID Gain [![](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M1IFMsiQH0N5uEseRXb%2Fuploads%2Fq2R7cAPb2cDKJIdSPnwG%2Ffile.gif?alt=media)](https://emacua.fandom.com/wiki/System_Interfaces?action=edit\§ion=11) | Field | Value | Function | Additional Field | | ----- | ------------- | ------------------ | ---------------- | | n | Float | Kp | N/A | | n+1 | Float | Ki | N/A | | n+2 | Float | Kd | N/A | | n+3 | unsigned long | Sample Time (mSec) | N/A | | n+4 | 'm' | Deadband: Min | N/A | | n+4 | 'M' | Deadband: Max | N/A | | n+4 | 'A' | Deadband: Auto | N/A | #### Additional Field: APinfo [![](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M1IFMsiQH0N5uEseRXb%2Fuploads%2FC0vHPcXOrfRFakN9kyMY%2Ffile.gif?alt=media)](https://emacua.fandom.com/wiki/System_Interfaces?action=edit\§ion=12) | Field | Value | Function | Additional Field | | ----- | ------------ | -------------------------------------- | ---------------- | | n | 'S' | STAND-BY Mode | N/A | | n | 'A' | AUTO Mode | N/A | | n | 'T' | TRACK Mode | N/A | | n | 'C' | Calibration Mode (IMU or Feedback) | N/A | | n+1 | Integer | Current Rudder | N/A | | n+2 | Float | Heading Magnetic (HDM) - Magnitude (M) | N/A | | n+3 | Float | Course To Steer (CTS) - Magnitude (M) | N/A | | n+4 | Positive int | Deadband value | N/A | | n+5 | Float | Trimming value | N/A | #### Additional Field: IMU Cal. values [![](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M1IFMsiQH0N5uEseRXb%2Fuploads%2Fq3Nzt2jzMSVFIUKTf19q%2Ffile.gif?alt=media)](https://emacua.fandom.com/wiki/System_Interfaces?action=edit\§ion=12) | Field | Value | Function | Additional Field | | ----- | --------------- | ------------------------------------------------------------ | ---------------- | | n | '-' | Calib. Not started | N/A | | n | 'O' | Calib. Ongoing | N/A | | n | 'R' | Recalibrated | N/A | | n | 'N' | Not calibrated | N/A | | n | 'C' | Check ongoing | N/A | | n+1 | 1:OK/ 0:NOK | Sys status. Ony valid when Calib is ongoing | N/A | | n+2 | 1:OK/ 0:NOK | Gyro status. Ony valid when Calib is ongoing | N/A | | n+3 | 1:OK/ 0:NOK | Accel status. Ony valid when Calib is ongoing | N/A | | n+4 | 1:OK/ 0:NOK | Magn status. Ony valid when Calib is ongoing | N/A | | n+5 | Int (0, 360) |

X euler angle.

Ony valid when Check is ongoing

| N/A | | n+6 | Int (-180, 180) |

Y euler angle.

Ony valid when Check is ongoing

| N/A | | n+7 | Int (0, 90) |

Z euler angle.

Ony valid when Check is ongoing

| N/A | | | | | | | | | | | #### Additional Field: IMU Cal. values [![](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M1IFMsiQH0N5uEseRXb%2Fuploads%2Fxziw9SatxmPw0FJi7bue%2Ffile.gif?alt=media)](https://emacua.fandom.com/wiki/System_Interfaces?action=edit\§ion=12) | Field | Value | Function | Additional Field | | ----- | ----- | ------------------ | ---------------- | | n | '-' | Calib. Not started | N/A | | n | | | | ## OpenCPN NMEA I/F OpenCPN integrates GPS and plotter capabilities to provide user with all required means to define a route and send it to Fenix Autopilot. OpenCPN is required for Nav mode. Fenix and OpenCPN implements NMEA I/F in both directions ### Data sent by OpenCPN to Fenix Autopilot in ALL working modes from different sources: * **External Compass (only in External Compass mode):** > Message: $HDM - Heading Magnetic {% hint style="warning" %} Features below are not available in V2.x {% endhint %} * **Windvane and calculations** * **GPS Fix** * **Speed Log** ### Data sent by OpenCPN to Fenix Autopilot in NAV Mode: #### Message: $APB - Autopilot Sentence "B" * **Route** * Waypoint ID * Course To Steer to Next Waypoint (CTS) - Magnetic angle * Cross Track Error (XTE) * Arrival Circle Alarm * Perpendicular Circle Alarm {% hint style="warning" %} Feature available with limitations in V0.1: Only APB message decoded. {% endhint %} ### Data sent from Fenix Autopilot to OpenCPN in ALL working modes: #### **Internal compass (in Internal Compass Mode only):** > Message: $HDM - Heading Magnetic > > Message: $HDT - Heading True #### **Rudder position** > Message: $RSA - Rudder Sensor Angle