EBB Commands

Introduction

Other Resources

• EBB Command FAQ
• Boot up configuration information
• Release notes for v2.0.1 to latest

Differences between 'standard' EggBot firmware version (2.0.1) and latest version (2.3.0)

EBB Command Reference

The "XM" Command (stepper motor move for mixed-axis geometries) - Added in version 2.3.0

• Format: "XM,<move_duration>,<axisA>,<axisB><CR>"
• <move_duration> is a value from 1 to 16777215 and is in milliseconds. It represents the total length of time you want this move to take.
• <axisA> and <axisB> are step values from -1677215 to 1677215 (see below)
  
• If both <axisA> and <axisB> are zero, then a delay of <move_duration> ms is executed.
• The sign of <axisA> and <axisB> represent the direction you want the motors to move.
  
• This command takes the <axisA> and <axisB> values, and creates a call to the SM command with the SM command's <Axis1> value as <AxisA> + <AxisB>, and <Axis2> as <AxisA> - <AxisB>.
• This command is designed to allow cleaner operation of machines like the H-Bot and CoreXY systems.
  
• The minimum speed at which the EBB can generate steps for each motor is 1.31 steps/second. The maximum speed is 25Ksteps/second. If the XM command finds that this speed range will be violated on either axis, it will output an error message declaring such and it will not complete the move. Note that the range is checked on Axis1 and Axis2, NOT on AxisA and AxisB. (I.e. post-math ops)
  
• Note that internally the EBB generates an ISR at the 25KHz rate. Each time the ISR fires, the EBB determines if a step needs to be taken for a given axis or not. The practical result of this is that all steps will be 'quantized' to the 25KHz (40uS) time intervals, and thus as the step rate gets close to 25Khz the 'correct' time between steps will not be generated, but instead each step will land on a 40uS tick in time. In almost all cases normally used by the EBB, this doesn't make any difference because the overall proper length for the entire move will be correct.
  
• A value of 0 for <move_duration> is invalid and will be rejected.

• Example: "XM,1000,550,-1234"
• Return Packet: "OK"

The "QC" Command (Query Current) - Added in v2.0, broken up to v2.2.2. Works properly in v2.2.3 and above.

• Format: "QC<CR>"
• Example: "QC"
• Returns: "<REF_RA0_VOLTAGE>,<V+_NET_VOLTAGE><CR>"
• <REF_RA0_VOLTAGE> is the voltage on the REF_RA0 net, as expressed as a 10 bit number where 0 = 0.0V and 1023 = 3.3V
• <V+_NET_VOLTAGE> is the voltage on the V+ net scaled by the resistor divider R13 and R18
• This command reads two analog voltages and returns their raw 10 bit values. You can use this to figure out what the user has set the current adjustment pot to, and to read the voltage coming into the board.
  
• Returns: "0421,0021<CR>OK<CR>"

Input (V+)    QC second parameter
0.0           449
5.0           513
9.0           574
12.0          604
24.0          775

• Format: "ES<CR>"
• Example: "ES"
• Use this command to abort any in-progress motor move (SM) command. This command will also delete any motor move command (SM) from the FIFO. It will immediately stop the motors, but leave them energized.
  
• This command will return a "1" if it had to stop an in-progress move command, or if it had to delete a move command from the FIFO. This would indicate that some steps might be lost, since the host application thinks the moves have already completed, when in fact they were aborted partway through. This command will return a "0" if no motor move commands were deleted or aborted.
  
• Returns:
• "1<CR>" or "0<CR", then
  
• "OK<CR>"
• Version Notes: In 2.2.9 and above, there are extra values in the reply to this command:
•  Returns: <command_interrupted>,<fifo_steps1>,<fifo_steps2>,<steps_remaining1>,<steps_remaining2><CR>OK<CR>
  <command_interrupted> = 0 if no FIFO or in-progress move commands were interrupted,
                          1 if a motor move command was in progress or in the FIFO
  <fifo_steps1> and <fifo_steps1> = 24 bit unsigned integers with the number of steps
                          in any SM command sitting in the fifo for axis1 and axis2.
  <steps_remaining1> and <steps_remaining2> = 24 bit unsigned integers with the number of
                          steps left in the currently executing SM command (if any) for
                          axis1 and axis2.
  It will return 0,0,0,0,0 if no SM command was executing at the time, and no SM command was in the FIFO.
  
  

The "SE" Command (Set Engraver) - Added in v2.1.0, updated in v2.4.1

• Format: "SE,<state>,<power><CR>" (pre v2.4.1)
• Format: "SE,<state>,<power>,<use_motion_queue><CR>" (v2.4.1 and on)
  
• Example: "SE,1,1023"
• <state> is 0 for disable, and 1 for enable. You must include this parameter.
• <power> is a value from 0 to 1023 and represents the relative power (% duty cycle of the PWM signal), where 0 is off and 1023 is full on. This parameter is optional.
• <use_motion_queue> is optional, and can be a 0 or a 1. If 1, then this SE command will be put on the motion queue just like SM and SP commands, thus it will be executed when the previous motion commands have finished. Note that if you need to use this parameter, the <power> parameter is not optional. (You must have 3 parameters if you use this parameter.)
  
• This command is used to enable and disable the engraver PWM output on RB3 (called B3 on the board), and also set its output power. Use SE,0 to disable this feature.
• If <power> is not included, 50% PWM will be used.
  
• Returns: "OK<CR>"
• Version Notes: Firmware versions prior to v2.2.2 do not have working PWM from this command. Instead, they always defaulted to 50% PWM. Version 2.2.2 fixes this problem.
  

The "NI" Command (Node count Increment) - Added in v1.9.5

• Format: "NI<CR>"
• Example: "NI"
• This command increments the 32 bit Node Counter by 1.
  
• Returns: "OK<CR>"

The "ND" Command (Node count Decrement) - Added in v1.9.5

• Format: "ND<CR>"
• Example: "ND"
• This command decrements the 32 bit Node Counter by 1.
  
• Returns: "OK<CR>"

The "BL" Command (BootLoad) - Added in v1.9.5

• Format: "BL<CR>"
• Example: "BL"
• This command turns off interrupts and jumps into the bootloader. The EBB will enter bootloader mode without having to push any buttons. Note that this command will ONLY work if you have a EBB bootloader version later than 7/3/2010 (the version released on 7/3/2010 has a distinct LED blink mode - the USB LED stays on 3 times longer than the USR LED). With a previous version of the bootloader code, this command may cause the EBB to be come unresponsive.
  
• Returns: "OK<CR>"

The "SN" Command (Set Node count) - Brought back in v1.9.5

• Format: "SN,<value><CR>"
• Example: "SN,123456789"
• This command sets the Node Counter to <value>. <value> is a 32 bit unsigned int.
  
• Returns: "OK<CR>"

The "CN" Command (Clear Node count) - Added in v1.9.3, removed in 1.9.5 and above

• Format: "CN<CR>"
• Example: "CN"
• This command clears the value of the Node Counter (see QN command).
  
• Returns: "OK<CR>"

The "SL" Command (Set Layer) - Added in v1.9.2

• Format: "SL,<NewLayerValue><CR>"
• Example: "SL,4"
• This command set the value of the Layer variable (see QL command).
  
• Returns:"OK<CR>"

The "QL" Command (Query Layer) - Added in v1.9.2

• Format: "QL<CR>"
• Example: "QL"
• This command asks the EBB to report back the current value of the Layer variable. This variable is set with the SL command, as is a single unsigned byte.
  
• Returns: "<CurrentLayerValue><CR>" then "OK<CR>"
• Example: "4" then "OK"
  

• Format: "QN<CR>"
• Example: "QN"
• This command asks the EBB what the current value of the Node Counter is. The Node Counter is an unsigned long int (8 bytes) value that gets incremented each time an SM command is finished executing.
  
• Returns: "<NodeCount><CR>OK<CR>"
• Example: "1234567890" then "OK"
  

The "QB" Command (Query Button) - Added in v1.9.2

• Format: "QB<CR>"
• Example: "QB"
• This command simply asks the EBB if the PRG button has been pressed since the last QB command or not.
  
• Returns: "1" if the PRG button has been pressed since the last QB command, "0" if it has not, then "OK"

The "QP" Command (Query Pen) - Added in v1.9

• Format: "QP<CR>"
• Example: "QP"
• This command simply asks the EBB what state the pen is in. It will return 1 if the pen is up and 0 if the pen is down. If a pen up/down command is pending in the FIFO, it will only report the new state of the pen after the pen move has been started.
  
• Return Packet: "1" if the pen is  UP, "0" if the pen is DOWN, then "OK"

The "TP" Command (Toggle Pen) - Added in v1.9

• Format: "TP,<duration><CR>"
• <duration> (optional parameter - if no value then 0 is used internally) is a value from 1 to 65,535 and is in milliseconds. It represents the total length of time between when the pen move is started, and when the next command will be executed. Note that this does not have anything to do with how fast the pen moves (which is set with the SC command). The <duration> parameter is to force the EBB not to execute the next command (normally an SM) for some length of time, which gives the system time to allow the pen move to complete and then some extra time before moving the motors (if you set up the pen speed and this duration parameter properly).
• Version Notes: In versions prior to 2.2.1, the <duration> parameter had a bug and was in units of 40uS rather than 1ms. Versions from 2.2.1 and on have this bug fixed.
  

• This command toggles the state of the pen (up->down and down->up). EBB firmware boots up with pen in 'up' (<servo_min>) state.
  

• Example: "TP"
• Return Packet: "OK"

The "SM" Command (stepper motor move)

• Format: "SM,<move_duration>,<axis1>,<axis2><CR>"
• <move_duration> is a value from 1 to 65,535 (for version 2.2.5 and above, this value can be up to 1677215) and is in milliseconds. It represents the total length of time you want this move to take.
• <axis1> and <axis2> are values from -32,767 to +32,767 (for version 2.2.5 and above, these values can be from -1677215 to 1677215) and represent the number of steps for each motor to take in <move_duration> milliseconds.
• If both <axis1> and <axis2> are zero, then a delay of <move_duration> ms is executed. <axis2> is an optional value, and if it is not included in the command, zero steps are assumed for axis 2.
• The sign of <axis1> and <axis2> represent the direction you want each motor to turn.
  

• Use this command to make the motors draw a straight line at constant velocity.
• The minimum speed at which the EBB can generate steps for each motor is 1.31 steps/second. The maximum speed is 25Ksteps/second. If the XM command finds that this speed range will be violated on either axis, it will output an error message declaring such and it will not complete the move. Note that the range is checked on Axis1 and Axis2, NOT on AxisA and AxisB. (I.e. post-math ops)
• Note that internally the EBB generates an ISR at the 25KHz rate. Each time the ISR fires, the EBB determines if a step needs to be taken for a given axis or not. The practical result of this is that all steps will be 'quantized' to the 25KHz (40uS) time intervals, and thus as the step rate gets close to 25Khz the 'correct' time between steps will not be generated, but instead each step will land on a 40uS tick in time. In almost all cases normally used by the EBB, this doesn't make any difference because the overall proper length for the entire move will be correct.
• A value of 0 for <move_duration> is invalid and will be rejected.

• Example: "SM,1000,250,-766"
• Return Packet: "OK"
• Version notes:
  
• In versions prior to 2.2.1, the <move_duration> parameter had a bug where values over 2621 would produce incorrect delays (when <axis1> and <axis2> are 0). This has been fixed for 2.2.1 and above, and now values up to 65,535 will work properly.
  As of version 2.2.5, the <move_duration>, <axis1>, and <axis2> parameters for this command are full 24 bit numbers. <move_duration> is an unsigned 24-bit value, while <axis1> and <axis2> are signed. This allows for some _very_ long stepper moves.
• As of version 2.2.8, the error messages for this command have been corrected. If an input parameter is too large (>1677215) or a step rate is too fast (>25K steps/s) or too slow (<1.31 steps/s) a proper error will be printed back to the host.
  

The "SP" Command (set pen state)

• Format: "SP,<value>,<duration>,<portBpin><CR>"
• <value> is 0 or 1
  
• <duration> (optional parameter - if no value then 0 is used internally) is a value from 1 to 65,535 and is in milliseconds. It represents the total length of time between when the pen move is started, and when the next command will be executed. Note that this does not have anything to do with how fast the pen moves (which is set with the SC command). The <duration> parameter is to force the EBB not to execute the next command (normally an SM) for some length of time, which gives the system time to allow the pen move to complete and then some extra time before moving the motors (if you set up the pen speed and this duration parameter properly).
• <portBpin> (optional - if not present, then 1 is used) Which port B pin you want this output to come out of (values from 0 through 7 are valid) (Note: this parameter is new for EBF 2.1.1 and above)
• When a <value> of 1 is used, the servo will be moved to the <servo_min> value (as set by the "SC,4" command below).
• When a <value> of 0 is used, the servo will be moved to the <servo_max> value (as set by the "SC,5" command below).
• Note that the EggBot Inkscape extension uses the <servo_min> ("SC,4") value as the 'Pen up position', and the <servo_max> ("SC,5") value as the 'Pen down position'.
  
• This command will make the pen go up or down. On EBB versions 1.1, 1.2 and 1.3 this will make the solenoid output turn on and off. On all EBB versions it will also make the RC servo output on RB1 move to the up or down position. Also, by default, it will turn on RB4 or turn off RB4 as a simple digital output, so that you could use this to trigger a laser for example.
• The default position for the RC servo output (RB1) on boot is the 'Pen up position' (<servo_min>), and at boot <servo_min> is set to 12000 which results in a pulse width of 1.0mS on boot. <servo_max> is set to 16000 on boot, so the down position will be 1.3mS unless changed with the "SC,5" command.
  
• Version Notes:In versions prior to 2.2.4, the <duration> parameter had two bugs. One was that the units for <duration> were 40uS (instead of the correct 1ms). The second was that the change of state of the servo would happen AFTER the delay had elapsed. Both of these bugs have been corrected in v2.2.4 and above. The servo move and the <duration> delay are both started simultaneously now.
  

• Example: "SP,1"
• Return Packet: "OK"

The "EM" Command (enable motors) for EBB v1.1

• Format: "EM,<EnableAxis1>,<EnableAxis2><CR>"
• Everything after <EnableAxis1> is optional
  
• For each axis:
• 0 will disable that axis (the driver will stop sending current to the motor, so the motor will freewheel)
• 1 will enable that axis in 1/8th step mode (default)
• 2 will enable that axis in 1/4 step mode
• 3 will enable that axis in 1/2 step mode
• 4 will enable that axis in full step mode
  
• Example: "EM,1,0"
• Return Packet: "OK"

The "EM" Command (enable motors) for EBB v1.2 and above

• Format: "EM,<Enable1>,<Enable2><CR>"
• To enable a motor driver, set its <Enable> parameter to 1.
  
• To disable a motor driver, set its <Enable> parameter to 0.
• For example, "EM,1,0" will enable motor 1 and disable motor 2.
• To set the microstep mode of BOTH motor drivers (the same signals go to both drivers, so you can't set them separately) use a value of 1,2,3,4 or 5 for <Enable1>.
• When setting microstep values with <Enable1>:
  
• 1 will enable both axis in 1/16th step mode (default on boot)
• 2 will enable both axis in 1/8th step mode
  
• 3 will enable both axis in 1/4 step mode
• 4 will enable both axis in 1/2 step mode
• 5 will enable both axis in full step mode
• Note that any time an SM command is executed, both motors become 'enabled' before the move starts. Thus it is almost never necessary to issue a "EM,1,1" command to enable both motors.
  
• Example: "EM,2" - this command will set both motors in 1/8th step mode
• Example: "EM,0,0" - this command will disable both motors (they will then freewheel)
• Example: "EM,1,1" - this command will enable both motors and set them to 1/16th microstep mode.
  
• Return Packet: "OK"

The "SC" Command (stepper mode configure)

• Format: "SC,<value1>,<value2><CR>"
• <value1> is a number from 0 to 255 - it's meaning is defined below
  
• <value2> is a number from 0 to 65535 - it's meaning depends upon <value1>
  

• This command allows you to set different parameters that effect the operation of the EBB.

• SC,1,0 - uses just the solenoid output (RB4) for pen up/down (no RC servo outputs)
• SC,1,1 - uses just the RC pen lift servo on RB1 for pen up/down (no solenoid output on RB4)
  
• SC,1,2 - uses solenoid (RB4) and RC servo (RB1) output for pen up/down, hardware RC output (default)
• SC,2,0 - Set PIC to control built-in stepper driver chips (default)
• SC,2,1 - Set PIC to control external step/direction drivers based on these pins.
  
• ENABLE1 = RD1
• ENABLE2 = RA1
• STEP1 = RC6
• DIR1 = RC2
• STEP2 = RA5
• DIR2 = RA2
  
• Note that SC,2,1 will also disconnect the PIC from the built-in motor drivers, so you can drive the step/direction/enable lines of the built-in drivers from the pins of J5 and J4 (they all come out there - see schematic) This command allows you to use the PIC as a step and direction generator for external step/dir drives.
  
• SC,2,2 - PIC is disconnected from built-in motor drivers and external pins - all step/dir/enable pins on the PIC are set to inputs. This allows you to completely control the built-in stepper motor driver chips externally with your own step/dir/enable signals. Use the pins listed in the schematic from J5 and J4. (new in 2.2.2)
  
• SC,4,<servo_min> - sets the minimum value for the servo (1 to 65535, in units of 83nS ). This is the 'Pen up position', and defaults to 12000 (1.0mS) on boot.
  
• SC,5,<servo_max> - sets the maximum value for the servo (1 to 65535, in units of 83nS). This is the 'Pen down position', and it defaults to 16000 (1.3mS) on boot.
  
• SC,8,<maximum_S2_channels> - sets the number of channels, each of <S2_channel_duration_ms> before cycling back to channel 1 for S2 command. Values from 1 to 24 are valid. Defaults to 8 on bootup. (new for EBB 2.1.1)
  
• SC,9,<S2_channel_duration_ms> - sets the number of milliseconds before firing the next enabled channel for the S2 command. Defaults to 3ms. (new for EBB 2.1.1)
  
• SC,10,<servo_rate> - sets both going up and going down rates of change for the servo. (Same as <rate> parameter in S2 command below)
  
• SC,11,<servo_rate_up> - sets the rate of change of the servo when going up (new in v1.9.2) (Same as <rate> parameter in S2 command below)
• SC,12,<servo_rate_down> - sets the rate of change of the servo when going down (new in v1.9.2) (Same as <rate> parameter in S2 command below)
• SC,13,<use_alt_pause> - turns on (1) or off (0) alternate pause button function on RB0. On by default. For v1.1 boards, it uses RB2 instead. (new in v2.0)


• Example: "SC,4,8000"
• Return Packet: "OK"

The "S2" Command (general RC servo output) - for versions prior to 2.2.0

• Format: "S2,<channel>,<position>,<output_pin>,<rate><CR>"
• <channel> is a number from 0 to 8 (with 0 as a special value which shuts off all S2 outputs)
  
• <position> is a number from 0 to 32,000, and represents the 'on' time in 1/12,000,000ths of a second (0 = channel off, 1=83us, 32,000 = 3ms)
  
• <output_pin> is a number from 0 to 24, and is the RPx pin number you want this channel to come out on- see schematic for RPx numbers
  
• <rate> is the rate at which to change from the current value to the new value. Use 0 to have changes instant. See below for the units of this value. Values from 0 to 65535 are valid. Optional parameter.
  
• This command is a generic RC servo output command. It allows you to control the RC servo output system on the EBB. Many I/O pins have RPx numbers (see the schematic) - and you can output RC servo pulses on up to 8 of these RPx pins. Any of them that you want - it doesn't matter to the software. There are seven RC servo 'channels', which have no physical meaning other than we can (by default) only output up to 8 separate signals at once. But you can assign any RPx pin to any channel - that's up to you to manage. The RC servo system will cycle through each of the 8 channels. Each gets 3m of 'time'. (Thus giving a 24ms repeat rate for the whole RC system.) If the current channel is enabled, then at the beginning of its 3ms time slot, it's RPx pin is set high. Then, <position> time later, the RPx pin is set low. This time is controlled purely by hardware (the ECCP2 in the CPU) so there is no jitter for the pulse durations. <position> is in units of 1/12,000 of a second, so 32,000 for <position> would be exactly 3ms.
• The number of available channels is normally (by default) 8. This can be changed with the SC,8 command (see above). The S2 RC servo output command cycles from channel 1 through channel <maximum_S2_channels> (normally 8), outputting any enabled channel's pulse from 0ms to 3ms. For a given channel, the repetition rate is determined by <maximum_S2_channels> * <S2_channel_duration_ms> which is normally 8 * 3 or 24ms. Thus, each channel's output pulse will be repeated every 24ms. Note that channel 0 is not a real channel - the <channel> = 0 value is used to disable all S2 functionality. If you change the <maximum_S2_channels> you will change the repetition rate of the pulses.
  
• The <rate> parameter is used to indicate how quickly to move from the current pulse width (servo position) to the new pulse width. If <rate> is zero, then the move is made on the next PWM cycle (i.e. the next time the pin is pulsed). If <rate> is not zero, then <rate> is added to (or subtracted from) the current pulse width each time the pulse is generated until the new target is reached. This means that the units of <rate> are 1/12,000ths of a second per <maximum_S2_channels> * <S2_channel_duration_ms> or 1/12,000ths of a second per 24ms.
• The normal pen up/down servo control (SP and TP commands) use S2 channel 1. So if you want to use SP and TP, then leave channel 1 alone and start with channel 2. If you don't care to use SP and TP anymore, then you can use channels 1 through <maximum_S2_channels>.
• The S2 command will always make <output_pin> an output before it starts outputting pulses to that pin.
  
• For example, to use RP6 as a RC servo output, and to set it's on-time to 2ms, and using channel 3 of the RC system, you would send the command (note <rate> is optional)
  
• S2,3,24000,6<CR>
• S2,0 - will turn off all RC servo support (freeing up CPU time, if that's important to you)
• S2,3,0 - will turn off the output on whatever pin channel 3 was assigned to.
  
• Return Packet: "OK"

The "S2" Command (general RC servo output) - for versions 2.2.0 and above

• Format: "S2,<position>,<output_pin>,<rate>,<delay><CR>"
• <position> is a number from 0 to 32,000, and represents the 'on' time in 1/12,000,000ths of a second (0 = off, 1=83us, 32,000 = 3ms)
  
• <output_pin> is a number from 0 to 24, and is the RPx pin number you want this channel to come out on- see schematic for RPx numbers
  
• <rate> is the rate at which to change from the current value to the new value. Use 0 to have changes instant. See below for the units of this value. Values from 0 to 65535 are valid. Optional parameter.
• <delay> is the number of milliseconds to delay the start of the next command (optional, defaults to 0 = instant)
  
• This command is a generic RC servo output command. It allows you to control the RC servo output system on the EBB. Many I/O pins have RPx numbers (see the schematic) - and you can output RC servo pulses on up to 8 of these RPx pins. Any of them that you want - it doesn't matter to the software. There are seven RC servo 'channels', which have no physical meaning other than we can (by default) only output up to 8 separate signals at once. But you can assign any RPx pin to any channel - that's up to you to manage. The RC servo system will cycle through each of the 8 channels. Each gets 3m of 'time'. (Thus giving a 24ms repeat rate for the whole RC system.) If the current channel is enabled, then at the beginning of its 3ms time slot, it's RPx pin is set high. Then, <position> time later, the RPx pin is set low. This time is controlled purely by hardware (the ECCP2 in the CPU) so there is no jitter for the pulse durations. <position> is in units of 1/12,000 of a second, so 32,000 for <duration> would be exactly 3ms.
• The <rate> parameter is used to indicate how quickly to move from the current pulse width (servo position) to the new pulse width. If <rate> is zero, then the move is made on the next PWM cycle (i.e. the next time the pin is pulsed). If <rate> is not zero, then <rate> is added to (or subtracted from) the current pulse width each time the pulse is generated until the new target is reached. This means that the units of <rate> are 1/12,000ths of a second per <maximum_S2_channels> * <S2_channel_duration_ms> or 1/12,000ths of a second per 24ms.
• The S2 command will always make <output_pin> an output before it starts outputting pulses to that pin.
  
• For example, to use RP6 (which is pin RB3) as a RC servo output, and to set it's on-time to 2ms,you would send the command (note <rate> and <delay> are optional)
  
• S2,24000,6<CR>
• S2,0 - will turn off all RC servo support (freeing up CPU time, if that's important to you)
• S2,0,5 - will turn off the output on RP5 (which is pin RB2) so it stops sending any pulses.
  
• Return Packet: "OK"
• More examples:
• Say you want to control a servo on RB2. (RB2 = RP5 as per schematic). You could send
• "S2,10000,5" to send a 1ms pulse out pin RB2. (This made my servo go full clockwise)
• "S2,27500,5" to send a 2.3ms pulse out pin RB2. (This made my servo go full counter-clockwise)
• You  have to experiment to see what <position> value makes your servo go all the way CW and all the way CCW. Each servo model is slightly different. Also it is common that servos will refuse to move at all if the pulse is outside their normal 'accepted' range (whatever that is for that model servo). So if you send a very short pulse (like 0.1mS) the servo may just completely ignore it rather than going all the way in one direction.
• RPn vs pin number table:
  

  RPn

  RP0

  RP1

  RP2

  RP3

  RP4

  RP5

  RP6

  RP7

  RP8

  RP9

  RP10

  RP11

  RP13

  RP17

  RP18

  Pin

  REF_RA0

  RA1

  RA5

  RB0

  RB1

  RB2

  RB3

  RB4

  RB5

  RB6

  RB7

  RC0

  RC2

  RC6

  RC7

  
  

• Format: "A<CR>"
• When any analog channels are enabled (see "AC" command below), the "A" command will cause the EBB to return a list of all enabled channels and their associated 10 bit values. Note that this is a different format from the "A" command that is in pre v2.2.3 versions. Before version 2.2.3, the "A" command format is the same as the normal UBW "A" command. (See UBW documentation for details.) Once the analog commands were re-written in v2.2.3, the AC command was added and the A command modified to return a list that includes the channel number as well as the ADC value for each channel.
• Format of return packet: "A,<channel>:<value>,<channel>:<value>. . . <CR>"
• The <value> returned for each enabled channel will range from 0 (for 0.0V on the input) to 1023 (for 3.3V on the input).
  
• The list of channels and their data will always be in sorted order from least (channel) to greatest. Only enabled channels will be present in the list.
• The channel number and ADC value are both padded to 2 and 4 characters respectively in the A response.
  
• Return Packet: "A,00:0713,02:0241,05:0089:09:1004<CR>" if channels 0, 2, 5 and 9 are enabled. 
• NOTE: Analog inputs can ONLY take up to 3.3V inputs. They are not able to take voltages more than 3.3V. Be careful not to put 5V on them or you may damage the pin.
• Also, if you connect an ADC pin to GND (0.0V) it will likely not read exactly 0. It will be a bit higher than that. (I got 0023 in my testing) This is because of the way that the analog input reference voltages are supplied to the PIC.
  

• Format: "AC,<channel>,<enable><CR>"
• <channel> is a number from 0 15, and represents the PIC's analog channel number (ANx on the schematic and datasheet) you wish to enable/disable.
  
• <enable> is either 1 to enable, or 0 to disable <channel>.
  
• Use this command to turn on or turn off individual analog channels. Once a channel is turned on, it will begin converting analog values to digital values and the results of the conversions will be displayed in the returned value of the "A" command. See "A" command above. You can turn on and off any of the 16 analog channels individually on this microcontroller. Once a channel is turned off, it will no longer show up in the "A" packet returned value list.
• You can find the pins that are analog inputs by looking at the EBB schematic, and looking at the pins on the PIC microcontroller. They will show ANx as one of their functions. For example, pin 11 of the PIC, which is labeled RB2 and comes out as the RB2 pin on the servo header, has the text "RB2/AN8/CTEDG1/PMA3/VMO/REFO/RP5" next to it on the CPU symbol. This means that this pin is connected to Analog Channel 8 inside the PIC. Check out chapter 21 of the PIC18F46J50 datasheet to read more about the ADC converter.
  
• Return Packet: "OK"

• Format: "QM<CR>"
• Return Packet: "QM,<CommandExecutingStatus>,<Motor1Status>,<Motor2Status>"
• <CommandExecutingStatus> will be 0 if there are no currently executing 'motion commands', and will be non-zero if there are any currently executing 'motion commands'.
  
• <Motor1Status> will be 0 if motor 1 is idle, and will be 1 if motor 1 is currently running
• <Motor2Status> will be 0 if motor 2 is idle, and will be 1 if motor 2 is currently running
• This command takes no parameters.
• Use this command to see what the EBB is currently doing. It will return the current state of the 'motion system' and each motor's current state.
• The definition of a 'motion command' is any command that has a time associated with it. For example, all SM commands. Also, any command (like S2, SP, or TP) that uses a <delay> or <duration> parameter. All of these commands cause the motion processor to 'do something' for some length of time, which then prevents later motion commands from running until they have finished.
  
• It is very important to realize that with the existing EBB firmware (all versions), there are a limited number of  'motion commands' that can be executing or queued up at a time. In fact, there can only be three. One (the first one) will be actually executing. Another one (the second) will be stored in the 1-deep FIFO that sits between the USB command processor and the motion engine that executes motion commands. Then the last one (the third) will be stuck in the USB command buffer, waiting for the 1-deep FIFO to be emptied before it can be processed. Once there are these three motion commands, the whole USB command processor will block (i.e. lock up) until the FIFO is cleared, and the third motion command can be processed and put into the FIFO. This means that NO USB commands can be processed by the EBB once the third motion command gets 'stuck' in the USB command processor. Using the QM command can help prevent this situation by allowing the PC to know when there are no more motion commands to be executed, and so can send the next one on.
  

EggBotBoard by Brian Schmalz is licensed under a Creative Commons Attribution 3.0 United States License.
Based on a work at www.schmalzhaus.com/EBB.
Permissions beyond the scope of this license may be available at www.schmalzhaus.com/EBB.