# 9. Setting reference

The Jrk G2 holds all of its settings in its non-volatile EEPROM memory. These settings are normally set ahead of time over USB using the Jrk G2 Configuration Utility. You can also read and write settings from the Jrk over USB using the --get-settings and --settings arguments to jrk2cmd. You can use the Jrk’s “Get settings” command to read these settings over serial and I²C, but you cannot change the EEPROM settings using those interfaces.

The Jrk stores a temporary copy of its settings in RAM, and the “Set RAM settings” and “Get RAM settings” commands allow you read and write from this copy over serial, I²C, and USB. This allows you to temporarily override most (but not all) settings.

This section lists all of the settings that the Jrk G2 supports. For each setting, this section contains several pieces of information:

• The Offset of each setting is the location where it is stored in the Jrk’s EEPROM memory. The offset is measured in bytes. You can use this offset with the “Read setting” and “Set setting” commands.
• The Type of each setting specifies how many bits the setting occupies, and says whether it is signed or unsigned (if applicable). All the multi-byte settings use little-endian format, meaning that the least-significant byte comes first.
• The Data entry for each setting specifies how the data for that setting is encoded in the Jrk’s memory. Some of the settings lack this field because they are simply dimensionless integers, so their encoding is straightforward.
• The Default entry for each setting is the default value it has on a new Jrk or a Jrk that has been reset to its defaults.
• The Range entry for each setting specifies what values the setting can have, if applicable. Trying to use a value outside of this range could result in unexpected behavior.
• The Settings file is the name of the setting in a Jrk settings file, if applicable. You can save and load Jrk settings files from the “File” menu of the Configuration utility, or by using the Jrk Command-line Utility (jrk2cmd).
• The Settings file data entry for each setting is the specification of how that setting is encoded in a settings file. Some of the settings lack this field because the encoding is straightforward.
• The Configuration utility entry is the location of that setting in the graphical user interface of the Jrk G2 configuration utility software, if applicable.
• The Temporary override available entry is “Yes” if changes made to the setting with the “Set RAM settings” command will have an immediate effect. Otherwise, you will need to set this setting ahead of time over USB using Jrk G2 configuration software.

#### Input mode

Offset 0x03 unsigned 8-bit 0: Serial / I²C / USB1: Analog voltage2: RC Serial / I²C / USB input_mode serialanalogrc Input tab, Input mode No

The input mode setting specifies how you want to control the Jrk. It determines the definition of the input and target variables. The input variable is a raw measurement of the Jrk’s input. The target variable is the desired state of the system’s output, and feeds into the PID feedback algorithm.

• If the input mode is “Serial / I²C / USB”, the Jrk gets its input and target settings over its USB, serial, or I²C interfaces. You can send Set Target commands to the Jrk to set both the input and target variables.
• If the input mode is “Analog voltage”, the Jrk gets it input variable by reading the voltage on its SDA/AN pin. A signal level of 0 V corresponds to an input value of 0, and a signal level of 5 V corresponds to an input value of 4092. The Jrk uses its input scaling feature to set the target variable.
• If the input mode is “RC”, the Jrk gets it input variable by reading RC pulses on its RC pin. The input value is the width of the most recent pulse, in units of 2/3 microseconds (0.666 μs). The Jrk uses its input scaling feature to set the target variable.

#### Input error minimum

Offset 0x04 unsigned 16-bit 0 0 to 4095 input_error_minimum Input tab, Scaling box, Input column, Error min Yes

If the raw input value is below this value, it causes an “Input disconnect” error. See Section 7.3.

#### Input error maximum

Offset 0x06 unsigned 16-bit 4095 0 to 4095 input_error_maximum Input tab, Scaling box, Input column, Error max Yes

If the raw input value is below this value, it causes an “Input disconnect” error. See Section 7.3.

#### Input minimum

Offset 0x08 unsigned 16-bit 0 0 to 4095 input_minimum Input tab, Scaling box, Input column, Minimum Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Input maximum

Offset 0x0A unsigned 16-bit 4095 0 to 4095 input_maximum Input tab, Scaling box, Input column, Maximum Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Input neutral minimum

Offset 0x0C unsigned 16-bit 2048 0 to 4095 input_neutral_minimum Input tab, Scaling box, Input column, Neutral min Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Input neutral maximum

Offset 0x0E unsigned 16-bit 2048 0 to 4095 input_neutral_maximum Input tab, Scaling box, Input column, Neutral max Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Target minimum

Offset 0x10 unsigned 16-bit 0 0 to 4095 output_minimum Input tab, Scaling box, Target column, Minimum Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Target neutral

Offset 0x12 unsigned 16-bit 2048 0 to 4095 output_neutral Input tab, Scaling box, Target column, Neutral Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Target maximum

Offset 0x14 unsigned 16-bit 4095 0 to 4095 output_maximum Input tab, Scaling box, Target column, Maximum Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Invert input direction

Offset bit 0 of byte 0x02 boolean 0: false1: true false input_invert true or false Input tab, Scaling box, Invert input direction Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Input scaling degree

Offset 0x16 unsigned 8-bit 0: linear1: quadratic2: cubic3: quartic4: quintic JRK_SCALING_DEGREE_LINEAR input_scaling_degree linearquadraticcubicquarticquintic Input tab, Scaling box, Degree Yes

This is one of the input scaling parameters that determines how the Jrk calculates its target value from its raw input. See Section 7.3.

#### Input detect disconnect

Offset bit 1 of byte 0x02 boolean 0: false1: true false input_detect_disconnect true or false Input tab, Detect disconnect with power pin (SCL) Yes

This determines whether the Jrk will drive the SCL pin low to detect when the input potentiometer has been disconnected. See Section 7.3.

#### Input analog samples exponent

Offset 0x17 unsigned 8-bit 7 (128 samples) 0 to 10 (1 sample to 1024 samples) input_analog_samples_exponent Input tab, Analog samples Yes

This setting specifies how many analog samples of the SDA/AN pin to take each PID period if it is being used as an analog input. The number of samples will be 2x where x is this setting. For more information, see Section 7.3.

#### Feedback mode

Offset 0x18 unsigned 8-bit 0: None1: Analog voltage2: Frequency (speed control) None feedback_mode noneanalogfrequency Feedback tab, Feedback mode No

The feedback mode setting specifies whether the Jrk is using feedback from the output of the system, and if so defines what type of feedback to use.

• If the feedback mode is “None”, feedback and PID calculations are disabled, and the Jrk will do open-loop control. The duty cycle target variable is always equal to the target variable minus 2048, instead of being the result of a PID calculation. This means that a target of 2648 corresponds to driving the motor at full speed forward, 2048 is stopped, and 1448 is full-speed reverse. See Section 5.1.
• If the feedback mode is “Analog voltage”, the Jrk gets its feedback by measuring the voltage on the FBA pin. A level of 0 V corresponds to a feedback value of 0, and a level of 5 V corresponds to a feedback value of 4092. The feedback scaling algorithm computes the scaled feedback variable, and the PID algorithm uses the scaled feedback and the target to compute the duty cycle target. See Section 7.4.
• If the feedback mode is “Frequency (speed control)”, the Jrk gets it feedback by measuring the frequency of a digital signal on the FBT pin. This mode is only suitable for speed control, not position control. See Section 7.4.

#### Feedback error minimum

Offset 0x19 unsigned 16-bit 0 0 to 4095 feedback_error_minimum Feedback tab, Error min Yes

If the raw feedback value is below this value, it causes a “Feedback disconnect” error. See Section 7.4.

#### Feedback error maximum

Offset 0x1B unsigned 16-bit 4095 0 to 4095 feedback_error_maximum Feedback tab, Error max Yes

If the raw feedback value exceeds this value, it causes a “Feedback disconnect” error. See Section 7.4.

#### Feedback minimum

Offset 0x1D unsigned 16-bit 0 0 to 4095 feedback_minimum Feedback tab, Minimum Yes

This is one of the parameters of the feedback scaling feature. See Section 7.4.

#### Feedback maximum

Offset 0x1F unsigned 16-bit 4095 0 to 4095 feedback_maximum Feedback tab, Maximum Yes

This is one of the parameters of the feedback scaling feature. See Section 7.4.

#### Invert feedback direction

Offset bit 2 of byte 0x02 boolean 0: false1: true false feedback_invert true or false Feedback tab, Invert feedback direction Yes

This is one of the parameters of the feedback scaling feature. See Section 7.4.

#### Feedback detect disconnect

Offset bit 3 of byte 0x02 boolean 0: false1: true false feedback_detect_disconnect true or false Feedback tab, Detect disconnect with power pin (AUX) Yes

This determines whether the Jrk will drive AUX low to detect if the feedback potentiometer has been disconnected. See Section 7.4.

Offset 0x21 unsigned 8-bit 0 0 to 255 feedback_dead_zone PID tab, Feedback dead zone Yes

If PID feedback is enabled, the Jrk sets the duty cycle target to zero and resets the integral whenever the magnitude of the error is smaller than this setting. See Section 7.5.

#### Feedback analog samples exponent

Offset 0x22 unsigned 8-bit 7 (128 samples) 0 to 10 (1 sample to 1024 samples) feedback_analog_samples_exponent Feedback tab, Analog samples Yes

This setting specifies how many analog samples of the FBA pin to take each PID period if it is being used as an analog input. The number of samples will be 2x where x is this setting. The samples are averaged together. For more information, see Section 7.4.

#### Feedback wraparound

Offset bit 4 of byte 0x02 boolean 0: false1: true false feedback_wraparound true or false Feedback tab, Wraparound Yes

This option, which is only available when the feedback mode is “Analog”, determines whether the PID algorithm will consider a scaled feedback value of 0 to be next to a scaled feedback value of 4095 when calculating the error. See Section 7.4.

#### Serial mode

Offset 0x23 unsigned 8-bit 0: USB dual port1: USB chained2: UART USB dual port serial_mode usb_dual_portusb_chaineduart Input tab, Serial interface box (radio buttons) No

The serial mode determines how bytes are transferred between the Jrk’s UART (TX and RX pins), its two USB virtual serial ports (the command port and the TTL Port), and its serial command processor.

• If the serial mode is “USB dual port”, the command port can be used to send commands to the Jrk and receive responses from it, while the TTL port can be used to send and receives bytes on the TX and RX lines. The baud rate set by the USB host on the TTL port determines the baud rate used on the TX and RX lines.
• If the serial mode is “USB chained”, the command port can be used to both transmit bytes on the TX line and send commands to the Jrk. The Jrk’s responses to those commands will be sent to the command port but not the TX line. If the RX line is enabled as a serial receive line, bytes received on the RX line will be sent to the command port but will not be interpreted as command bytes by the Jrk. The baud rate set by the USB host on the command port determines the baud rate used on the TX and RX lines.
• If the serial mode is “UART”, the TX and RX lines can be used to send commands to the Jrk and receive responses from it. Any byte received on RX will be sent to the command port, but bytes sent from the command port will be ignored.

#### Serial baud rate

Offset 0x24 unsigned 16-bit 16-bit baud rate generator (see below) 0x4E1 (9600 bits per second) serial_baud_rate Baud rate in bits per second Input tab, Serial interface box, fixed baud rate No

This setting specifies the baud rate to use on the RX and TX pins when the serial mode is UART. In other serial modes, the baud rate defaults to 9600, but can be changed over USB using the standard USB CDC ACM command.

The settings file and the configuration utility show the baud rate in bits per second, but it is actually stored on the Jrk as an unsigned 16-bit integer called the baud rate generator. The baud rate will be 12 Mbps divided by the baud rate generator.

#### Serial timeout

Offset 0x26 unsigned 16-bit Timeout in units of 10 ms 0 0 to 655,350 ms serial_timeout Timeout in units of milliseconds Input tab, Serial interface, Timeout (s) Yes

This is the time before the device reports a “Serial timeout error” if it has not received certain commands. A value of 0 disables the command timeout feature. See Section 7.7 for details about the serial timeout error.

The configuration utility presents the timeout in seconds, with two digits after the decimal point. The settings file has the timeout in units of milliseconds. The Jrk itself stores it as an unsigned 16-bit number with units of 10 ms, so the maximum possible value is 655,350 ms.

#### Serial device number

Offset 0x28 unsigned 16-bit 11 0 to 16383 serial_device_number Input tab, Serial interface, Device number No

This is the serial device number used in the Pololu protocol on the Jrk’s serial interfaces, and the I²C device address used on the Jrk’s I²C interface.

By default, the Jrk only pays attention to the lower 7 bits of this setting, but if you enable 14-bit serial device numbers then it will use the lower 14 bits for the serial interface (but the I²C interface will still only use the lower 7 bits).

See Section 12 and Section 13.

#### Never sleep

Offset bit 0 of byte 0x01 boolean 0: false1: true false never_sleep true or false Advanced tab, Miscellaneous, Never sleep (ignore USB suspend) Yes

By default, if the Jrk is powered from a USB bus that is in suspend mode (e.g. the computer is sleeping) and VIN power is not present, it will go to sleep to reduce its current consumption and comply with the USB specification. If this setting is set to true, the Jrk will never go to sleep.

#### Enable CRC

Offset bit 1 of byte 0x01 boolean 0: false1: true false serial_enable_crc true or false Input tab, Serial interface, Enable CRC No

If set to true, the Jrk requires a 7-bit CRC byte at the end of each serial command, and if the CRC byte is wrong then it ignores the command and sets the serial CRC error bit. See Section 12.

#### Enable 14-bit device number

Offset bit 2 of byte 0x01 boolean 0: false1: true false serial_enable_14bit_device_number true or false Input tab, Serial interface, Enable 14-bit device number No

If enabled, the Jrk’s Pololu protocol for serial commands will require a 14-bit device number to be sent with every command, instead of normal 7-bit device number. This option allows you to put more than 128 Jrk devices on one serial bus and control them individually. See Section 12.

#### Disable compact protocol

Offset bit 3 of byte 0x01 boolean 0: false1: true false serial_disable_compact_protocol true or false Input tab, Serial interface, Disable compact protocol No

If enabled, the Jrk will not respond to compact protocol serial commands. See Section 12.

#### Proportional multiplier

Offset 0x51 unsigned 16-bit 0 0 to 1023 proportional_multiplier PID tab, Proportional coefficient, Upper left Yes

This is the multiplier for the proportional coefficient used in the PID calculation. See Section 7.5.

#### Proportional exponent

Offset 0x53 unsigned 8-bit 0 0 to 18 proportional_exponent PID tab, Proportional coefficient, Lower left Yes

This is the exponent for the proportional coefficient used in the PID calculation. See Section 7.5.

#### Integral multiplier

Offset 0x54 unsigned 16-bit 0 0 to 1023 integral_multiplier PID tab, Integral coefficient, Upper left Yes

This is the multiplier for the integral coefficient used in the PID calculation. See Section 7.5.

#### Integral exponent

Offset 0x56 unsigned 8-bit 0 0 to 18 integral_exponent PID tab, Integral coefficient, Lower left Yes

This is the exponent for the integral coefficient used in the PID calculation. See Section 7.5.

#### Derivative multiplier

Offset 0x57 unsigned 16-bit 0 0 to 1023 derivative_multiplier PID tab, Derivative coefficient, Upper left Yes

This is the multiplier for the derivative coefficient used in the PID calculation. See Section 7.5.

#### Derivative exponent

Offset 0x59 unsigned 8-bit 0 0 to 18 derivative_exponent PID tab, Derivative coefficient, Lower left Yes

This is the exponent for the derivative coefficient used in the PID calculation. See Section 7.5.

#### PID period

Offset 0x5A unsigned 16-bit PID period in units of milliseconds 10 ms 1 ms to 8191 ms pid_period PID tab, PID period Yes

The PID period specifies how often the Jrk should calculate its input and feedback, run its PID calculation, and update the motor speed, in units of milliseconds. This period is still used even if feedback and PID are disabled. See Section 7.5.

#### Integral divider exponent

Offset 0x3F unsigned 8-bit 0 0 to 15 integral_divider_exponent PID tab, Integral divider Yes

This setting determines the “Integral divider” described in Section 7.5. The integral divider is 2x where x is this setting.

#### Integral limit

Offset 0x5C unsigned 16-bit 1000 0 to 32767 integral_limit PID tab, Integral limit Yes

See Section 7.5.

#### Reset integral when proportional term exceeds max duty cycle

Offset bit 0 of byte 0x50 boolean 0: false1: true false reset_integral true or false PID tab, Reset integral when proportional term exceeds max duty cycle Yes

See Section 7.5.

#### PWM frequency

Offset 0x32 unsigned 8-bit 0: 20 kHz1: 5 kHz 20 kHz pwm_frequency 20 or 5 Motor tab, PWM frequency Yes

See Section 7.6.

#### Current samples exponent

Offset 0x33 unsigned 8-bit 7 (128 samples) 0 to 10 (1 sample to 1024 samples) current_samples_exponent Motor tab, Current samples Yes

This setting specifies how many analog samples of the Jrk’s internal current sense pin to take each PID period. The number of samples will be 2x where x is this setting. The samples are averaged together. For more information, see Section 7.6.

#### Hard overcurrent threshold

Offset 0x34 unsigned 8-bit 1 1 to 255 hard_overcurrent_threshold Motor tab, Hard overcurrent threshold Yes

This setting is only available for the Jrk G2 18v19, 24v13, 18v27, and 24v21. See Section 7.6.

#### Current offset calibration

Offset 0x35 signed 16-bit 0 -800 to 800 current_offset_calibration Motor tab, Current offset calibration Yes

See Section 7.6.

#### Current scale calibration

Offset 0x37 signed 16-bit 0 -1875 to 1875 current_scale_calibration Motor tab, Current scale calibration Yes

See Section 7.6.

#### Invert motor direction

Offset bit 5 of byte 0x02 boolean 0: false1: true false motor_invert true or false Motor tab, Invert motor direction Yes

Flips the polarity of the voltage applied to the motor. See Section 7.6.

#### Max. duty cycle forward

Offset 0x68 unsigned 16-bit 600 0 to 600 max_duty_cycle_forward Motor tab, Max. duty cycle, Forward column Yes

See Section 7.6.

#### Max. duty cycle reverse

Offset 0x6A unsigned 16-bit 600 0 to 600 max_duty_cycle_reverse Motor tab, Max. duty cycle, Reverse column Yes

See Section 7.6.

#### Max duty cycle while feedback is out of range

Offset 0x5E unsigned 16-bit 600 1 to 600 max_duty_cycle_while_feedback_out_of_range Motor tab, Max. duty cycle while feedback is out of range Yes

See Section 7.6.

#### Max. acceleration forward

Offset 0x60 unsigned 16-bit 600 1 to 600 max_acceleration_forward Motor tab, Max. acceleration, Forward column Yes

See Section 7.6.

#### Max. acceleration reverse

Offset 0x62 unsigned 16-bit 600 1 to 600 max_acceleration_reverse Motor tab, Max. acceleration, Reverse column Yes

See Section 7.6.

#### Max. deceleration forward

Offset 0x64 unsigned 16-bit 600 1 to 600 max_deceleration_forward Motor tab, Max. deceleration, Forward column Yes

See Section 7.6.

#### Max. deceleration reverse

Offset 0x66 unsigned 16-bit 600 1 to 600 max_deceleration_reverse Motor tab, Max. deceleration, Reverse column Yes

See Section 7.6.

#### Hard current limit forward

Offset 0x6C unsigned 16-bit Encoded Depends on the product encoded_hard_current_limit_forward Motor tab, Hard current limit, Forward column Yes

This setting specifies the hardware current limit that the Jrk will use when driving in the forward direction.

This setting is not actually stored in the Jrk as a current; it is stored as an encoded value telling the Jrk how to set up its current limiting hardware. The correspondence between the encoded value and the actual current limit in milliamps depends on what product you are using and the characteristics of your particular unit as represented by the “Current offset calibration” and “Current scale calibration” settings. You can get a table in CSV format showing the correspondence by connecting the Jrk into a computer via USB and running jrk2cmd --current-table.

The default value for this setting depends on what Jrk product you have, as described in the table below:

Jrk product Default hard current limit
18v19 28.47 A (86)
24v13 19.34 A (62)
18v27 40.25 A (87)
24v21 31.53 A (63)

This setting is only available for the Jrk G2 18v19, 24v13, 18v27, and 24v21. See Section 7.6 for more information.

#### Hard current limit reverse

Offset 0x6E unsigned 16-bit Encoded Depends on the product encoded_hard_current_limit_reverse Motor tab, Hard current limit, Reverse column Yes

See the hard current limit forward setting. This setting is the same except it applies when driving in the reverse direction. This setting is only available for the Jrk G2 18v19, 24v13, 18v27, and 24v21.

#### Brake duration forward

Offset 0x70 unsigned 8-bit Duration in units of 5 ms 0 0 to 1275 ms brake_duration_forward Duration in units of milliseconds Motor tab, Brake duration, Forward column Yes

See Section 7.6.

#### Brake duration reverse

Offset 0x71 unsigned 8-bit Duration in units of 5 ms 0 0 to 1275 ms brake_duration_reverse Duration in units of milliseconds Motor tab, Brake duration, Reverse column Yes

See Section 7.6.

#### Soft current limit forward

Offset 0x72 unsigned 16-bit Current in units of milliamps, 0 means no limit 0 0 to 65,535 mA soft_current_limit_forward Current in units of milliamps Motor tab, Soft current limit, Forward column Yes

See Section 7.6.

#### Soft current limit reverse

Offset 0x74 unsigned 16-bit Current in units of milliamps, 0 means no limit 0 0 to 65,535 mA soft_current_limit_reverse Current in units of milliamps Motor tab, Soft current limit, Reverse column Yes

See Section 7.6.

#### Soft current regulation level forward

Offset 0x40 unsigned 16-bit Current in units of milliamps, 0 means disabled 0 0 to 65,535 mA soft_current_regulation_level_forward Current in units of milliamps Motor tab, Soft current regulation level, Forward column Yes

This setting is only available on the Jrk G2 21v3. See Section 7.6.

#### Soft current regulation level reverse

Offset 0x42 unsigned 16-bit Current in units of milliamps, 0 means disabled 0 0 to 65,535 mA soft_current_regulation_level_reverse Current in units of milliamps Motor tab, Soft current regulation level, Reverse column Yes

This setting is only available on the Jrk G2 21v3. See Section 7.6.

#### Coast when off

Offset bit 1 of byte 0x50 boolean 0: false1: true false coast_when_off true or false Motor tab, When motor is off Yes

See Section 7.6.

#### Error enable

Offset 0x2A unsigned 16-bit 0 error_enable Errors tab Yes

This setting holds a bit for each error that the Jrk supports. The correspondence between bits and errors is defined in Section 7.7. The bit is 1 if the corresponding error is enabled, and 0 otherwise. Note that an error that is “Enabled & latched” counts as being enabled.

The “Awaiting command”, “No power”, “Motor driver error”, and “Input invalid” errors are always enabled and cannot be disabled, so the bits corresponding to those errors in this setting are ignored.

#### Error latch

Offset 0x2C unsigned 16-bit 0 error_latch Errors tab Yes

This setting holds a bit for each error that the Jrk supports. The correspondence between bits and errors is defined in Section 7.7. The bit is 1 if the corresponding error is enabled and latched, or 0 otherwise.

The bits in this register are ignored for errors that are not enabled. (If an error is not enabled, its error flag will never be set, so there is no concept of the error flag being latched.) Also, the “Awaiting command” error and all the serial errors are always latching errors if they are enabled, so bits corresponding to those errors in this setting are ignored.

#### Error hard stop

Offset 0x2E unsigned 16-bit 0 error_hard Errors tab Yes

This setting holds a bit for each error that the Jrk supports. The correspondence between bits and errors is defined in Section 7.7. The bit is 1 if the corresponding error is configured as a hard stop error, or 0 otherwise.

The “No power” and “Motor driver” errors are always hard stop errors. The bits corresponding to those errors in this setting are ignored.

#### VIN calibration

Offset 0x30 signed 16-bit 0 -500 to 500 vin_calibration Advanced tab, Miscellaneous, VIN measurement calibration Yes

The firmware uses this calibration factor when calculating the VIN voltage. One of the steps in the process is to multiply the VIN voltage reading by 825 plus the VIN calibration. Therefore, for every 8 counts that you add or subtract from the VIN calibration setting, you increase or decrease the VIN voltage reading by about 1%.

#### Disable I²C pull-ups

Offset bit 4 of byte 0x01 boolean 0: false1: true false disable_i2c_pullups true or false Advanced tab, Disable I²C pull-ups No

This option disables the internal pull-up resistors on the SDA/AN and SCL pins if those pins are being used for I²C communication. Normally, the pull-ups are enabled to ensure that each bus line goes high when no devices are driving it.

Offset bit 5 of byte 0x01 boolean 0: false1: true false analog_sda_pullup true or false Advanced tab, Enable pull-up for analog input on SDA/AN No

This option enables the internal pull-up resistor on the SDA/AN pin if it is being used as an analog input.

Offset bit 6 of byte 0x01 boolean 0: false1: true false always_analog_sda true or false Advanced tab, Always configure SDA/AN for analog input No

This option causes the Jrk to perform analog measurements on the SDA/AN pin and configure SCL as a potentiometer power pin even if the “Input mode” setting is not “Analog”.

Offset bit 7 of byte 0x01 boolean 0: false1: true false always_analog_fba true or false Advanced tab, Always configure FBA for analog input No

This option causes the Jrk to perform analog measurements on the FBA pin even if the “Feedback mode” setting is not “Analog”.

#### FBT method

Offset 0x39 unsigned 8-bit 0: Pulse counting1: Pulse timing Pulse counting fbt_method countingtiming Feedback tab, Frequency feedback on FBT, Measurement method No

See Section 7.4.

#### FBT timing clock

Offset bits 4 through 6 of byte 0x3A unsigned 8-bit 0: 12 MHz1: 6 MHz2: 3 MHz3: 1.5 MHz4: 48 MHz5: 24 MHz 1.5 MHz 0 to JRK_FBT_TIMING_CLOCK_24 fbt_timing_clock 12m6m3m1m548m24m Feedback tab, Frequency feedback on FBT, Pulse timing clock No

See Section 7.4.

#### FBT timing polarity

Offset bit 0 of byte 0x3A boolean 0: Active high1: Active low Active high fbt_timing_polarity true (active high) or false (active low) Feedback tab, Frequency feedback on FBT, Pulse timing polarity No

By default, the pulse timing mode on the FBT pin measures the time of high pulses. When true, this option causes it to measure low pulses. See Section 7.4.

#### FBT timing timeout

Offset 0x3B unsigned 16-bit Timeout in milliseconds 100 1 to 60000 fbt_timing_timeout Feedback tab, Frequency feedback on FBT, Pulse timing timeout Yes

The pulse timing mode for the FBT pin will assume the motor has stopped, and start recording maximum-width pulses if it has not seen any pulses in this amount of time. See Section 7.4.

#### FBT samples

Offset 0x3D unsigned 8-bit 1 1 to 32 fbt_samples Feedback tab, Frequency feedback on FBT, Pulse samples No

The number of consecutive FBT measurements to average together in pulse timing mode or to add together in pulse counting mode. See Section 7.4.

#### FBT divider exponent

Offset 0x3E unsigned 8-bit 0 0 to 15 fbt_divider_exponent Feedback tab, Frequency feedback on FBT, Frequency divider Yes

This setting determines the “Frequency divider” described in Section 7.4. The frequency divider is 2x where x is this setting.

#### Not initialized

Offset 0x00 unsigned 8-bit 0: falsenon-zero: true false

This special setting keeps track of whether the rest of the settings have been initialized or not. Normally it is zero, which means false. If you set it to a non-zero value, then the Jrk will reset all of the settings to their default values the next time the Jrk is reset or reinitialized. This is how the “Restore default settings” command in the Jrk G2 Configuration Utility and the --restore-defaults option in the command-line utility are implemented.

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