Troubleshooting

WARNING: this page needs to be updated to become compatible with Fast Stacker v2.0
= Rail issues =
== After a software upgrade, weird things happen ==
Issue: Some parameters have crazy values. 
The solution: do a factory rest (press "#*" keys combo). Alternatively, re-upload the firmware, making sure to set "Tools > Erase Flash" to "All Flash Contents" in Arduino IDE.
== Motor skips some steps ==
This is manifested by fairly loud clicking noise when the rail is moving. It happens when the motor doesn't have enough of torque to move the camera.
First, make sure the tiny pot on your motor driver board is set to the maximum current your motor + AC adapter can handle. Measure VREF voltage straight from the pot (it has a metal top), to the ground. Your Current Limit = VREF × 2. For example, set VREF to 0.75V to get 1.5A current limit per coil.
If that doesn't solve the issue - perhaps the rail has some mechanical issues (it takes too much effort to turn the focusing knob), or the alignment of the motor shaft with the focusing knob is not great.
Finally, the batteries you are using might be not very good, or need to be recharged. Test if using an AC power solves the issue.
If all else fails, you can mitigate this problem by reducing the SPEED_LIMIT_MM_S parameter in stacker.h. You can also try to reduce the number of microsteps per step. Change the N_MICROSTEPS parameter in stacker.h, and also the parmeters MOTOR_M0, MOTOR_M1, MOTOR_M2 accordingly. (You will lose positional accuracy with this mod.)
== Limiting switches behave erratically ==
This issue plagued my old (pre-h2.0) designs. In h2.0, I found the proper solution: solder a 10nF ceramic capacitor between the limiter switch reading pin (D8) and the ground - right on top of the microcontroller. This will eliminate impulse noise coming from the stepper motor wiring.
= Camera issues =
== In continuous stacking, camera doesn't take any shots ==
Perhaps you need to set AF_SYNC to 1 in stacker.h
Another possibility - if you enabled the Mirror lock feature in your camera. If so, you should disable it when using continuous stacking mode. You can only enable it when using non-continuous stacking. In the latter case, make sure the mirror lock parameter is on (*C function).
== In continuous stacking, camera ignores the first shot ==
In stacker.h, if AF_SYNC=0, try to increase CONT_STACKING_DELAY value.
== Some shots are not taken ==
Perhaps increasing one or more of the following parameters in stacker.h can help: SHUTTER_TIME_US, SHUTTER_ON_DELAY, SHUTTER_OFF_DELAY.
Or could be because your camera doesn't support the current FPS parameter - try to reduce it until the problem goes away.