This document provides a list of steps to help confirm the pin
settings in the Klipper printer.cfg file.  It is a good idea to run
through these steps after following the steps in the
[installation document](Installation.md).

During this guide, it may be necessary to make changes to the Klipper
config file. Be sure to issue a RESTART command after every change to
the config file to ensure that the change takes effect (type "restart"
in the Octoprint terminal tab and then click "Send"). It's also a good
idea to issue a STATUS command after every RESTART to verify that the
config file is successfully loaded.

### Verify temperature

Start by verifying that temperatures are being properly
reported. Navigate to the Octoprint temperature tab.

![octoprint-temperature](img/octoprint-temperature.png)

Verify that the temperature of the nozzle and bed (if applicable) are
present and not increasing. If it is increasing, remove power from the
printer. If the temperatures are not accurate, review the
"sensor_type" and "sensor_pin" settings for the nozzle and/or bed.

### Verify M112

Navigate to the Octoprint terminal tab and issue an M112 command in
the terminal box. This command requests Klipper to go into a
"shutdown" state. It will cause Octoprint to disconnect from Klipper -
navigate to the Connection area and click on "Connect" to cause
Octoprint to reconnect. Then navigate to the Octoprint temperature tab
and verify that temperatures continue to update and the temperatures
are not increasing. If temperatures are increasing, remove power from
the printer.

The M112 command causes Klipper to go into a "shutdown" state. To
clear this state, issue a FIRMWARE_RESTART command in the Octoprint
terminal tab.

### Verify heaters

Navigate to the Octoprint temperature tab and type in 50 followed by
enter in the "Tool" temperature box. The extruder temperature in the
graph should start to increase (within about 30 seconds or so). Then
go to the "Tool" temperature drop-down box and select "Off". After
several minutes the temperature should start to return to its initial
room temperature value. If the temperature does not increase then
verify the "heater_pin" setting in the config.

If the printer has a heated bed then perform the above test again with
the bed.

### Verify stepper motor enable pin

Verify that all of the printer axes can manually move freely (the
stepper motors are disabled). If not, issue an M84 command to disable
the motors. If any of the axes still can not move freely, then verify
the stepper "enable_pin" configuration for the given axis. On most
commodity stepper motor drivers, the motor enable pin is "active low"
and therefore the enable pin should have a "!" before the pin (for
example, "enable_pin: !ar38").

### Verify endstops

Manually move all the printer axes so that none of them are in contact
with an endstop. Send a QUERY_ENDSTOPS command via the Octoprint
terminal tab. It should respond with the current state of all of the
configured endstops and they should all report a state of "open". For
each of the endstops, rerun the QUERY_ENDSTOPS command while manually
triggering the endstop. The QUERY_ENDSTOPS command should report the
endstop as "TRIGGERED".

If the endstop appears inverted (it reports "open" when triggered and
vice-versa) then add a "!" to the pin definition (for example,
"endstop_pin: ^!ar3"), or remove the "!" if there is already one
present.

If the endstop does not change at all then it generally indicates that
the endstop is connected to a different pin. However, it may also
require a change to the pullup setting of the pin (the '^' at the
start of the endstop_pin name - most printers will use a pullup
resistor and the '^' should be present).

### Verify stepper motor direction

Make sure the printer.cfg file does not have "homing_speed" set for
any axis (or set it to a value of 5 or less).

On cartesian style printers, manually move the X axis to a midway
point, issue a G28X0 command, and verify that the X motor moves slowly
towards the endstop defined for that axis. If the motor moves in the
wrong direction issue an M112 command to abort the move. A wrong
direction generally indicates that the "dir_pin" for the axis needs to
be inverted. This is done by adding a '!' to the "dir_pin" in the
printer config file (or removing it if one is already there). For
example, change "dir_pin: xyz" to "dir_pin: !xyz". Then RESTART and
retest the axis. If the axis does not move at all, then verify the
"enable_pin" and "step_pin" settings for the axis. For cartesian style
printers, repeat the test for the Y and Z axis with G28Y0 and G28Z0.

For delta style printers, manually move all three carriages to a
midway point and then issue a G28 command. Verify all three motors
move simultaneously upwards. If not, issue an M112 command and follow
the troubleshooting steps in the preceding paragraph.

### Verify extruder motor

To test the extruder motor it will be necessary to heat the extruder
to a printing temperature. Navigate to the Octoprint temperature tab
and select a target temperature from the temperature drop-down box (or
manually enter an appropriate temperature). Wait for the printer to
reach the desired temperature. Then navigate to the Octoprint control
tab and click the "Extrude" button. Verify that the extruder motor
turns in the correct direction. If it does not, see the
troubleshooting tips in the previous section to confirm the
"enable_pin", "step_pin", and "dir_pin" settings for the extruder.

### Calibrate PID settings

Klipper supports
[PID control](https://en.wikipedia.org/wiki/PID_controller) for the
extruder and bed heaters. In order to use this control mechanism it is
necessary to calibrate the PID settings on each printer. (PID settings
found in other firmwares or in the example configuration files often
work poorly.)

To calibrate the extruder, navigate to the OctoPrint terminal tab and
run the PID_CALIBRATE command. For example: `PID_CALIBRATE
HEATER=extruder TARGET=170`

At the completion of the tuning test, update the printer.cfg file with
the recommended pid_Kp, pid_Ki, and pid_Kd values.

If the printer has a heated bed and it supports being driven by PWM
(Pulse Width Modulation) then it is recommended to use PID control for
the bed. (When the bed heater is controlled using the PID algorithm it
may turn on and off ten times a second, which may not be suitable for
heaters using a mechanical switch.) A typical bed PID calibration
command is: `PID_CALIBRATE HEATER=heater_bed TARGET=60`

### Next steps

This guide is intended to help with basic verification of pin settings
in the Klipper configuration file. It may be necessary to perform
detailed printer calibration - a number of guides are available online
to help with this (for example, do a web search for "3d printer
calibration").
