Camera Setup calibration issues

I have been running the new Setup procedures for my FarmBot Express V1.0. I ran into some issues with the camera calibration.

  1. Using the multiple white dot calibration card, when I pressed the calibrate button, the z-axis started going down and smashed into the card on the ground. Tried twice with same outcome. I then tried the alternate method with the two red dots and that was successful,.
    2.) The calibrate height worked although it took longer than I was expecting. It would be good to provide a time estimate or progress bar.
    3.) The last camera calibration step was a odd in that it said to move the camera to a known position but it never asked for input as to what that position was. So, not sure what that step does.
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Hi @dlmcshan ,

That is unfortunate since the card method is usually the easier and more accurate method. It sounds like there is an issue with motor calibration. Does performing a “FIND HOME” operation beforehand help the situation? Please let me know. This is what the FIND HOME button looks like on the controls page:


Unfortunately, it is a very CPU-intensive process. Even on Genesis, this process can take a long time. The Express has a slower CPU than the full version, making the operation take even longer. I will make a note of your feature request. In the future, we may move this operation into the cloud where the operation can be performed on higher-powered machines, thereby providing a better experience for Express users.

Please let me know if the FIND HOME helps the situation. I will forward this report to the rest of the team for further investigation.

May I ask to what you have set the camera resolution? The higher the resolution, the more time it needs to process. I know higher resolution will give you nicer crisper images, but if you’re on an Express bot you probably shouldn’t go higher than 640 * 480 px resolution.

That said, things taking a “long time” is really a subjective matter. We humans are an impatient bunch. We want to see results, especially when we’re testing and trying stuff. But eventually, when you feel assured the bot can perform its tasks unattended, it really does not matter how long it takes to execute.

I’m already thinking about drastically lowering my steps-per-second once I’m confident the bot operates as desired, simply because it increases its accuracy and fault-tolerance and it won’t bother me anymore.

The same could be said in your case: lower the camera resolution and test calibration. Once you find that it works and is accurate, increase the resolution. You must recalibrate after changing resolution but now you know it will succeed (still you should confirm this) but you won’t be bothered even if it takes 15 minutes to complete the task.

FarmBot’s have 24 hours a day to work.

The home button raises the vertical to the hard stop but I have to press E-Stop to stop the motor running. So, I am guessing there is a bit of calibrating needed.
The Go to Home button puts the vertical gantry about halfway up and positions it near the middle of one end of the bed.
I will do some measurements.

After you have E-stopped it, go to your Axes settings and:

  • click Set Home Z in the Z-axis column;
  • set STOP AT HOME to YES in the Z-axis column.

If you want to prevent it from hitting the end-stop at the other end of the axis, you’ll want to extend it as far as you’ll allow, then take note of the Z position and:

  • enter the Z-position (without - minus symbol) in the SET AXIS LENGTH (MM) field in the Z-axis column;
  • set STOP AT MAX to YES in the Z-axis column.

For example, after you used the jog controls on the Controls screen, your Z position is now -451. You enter the axis length as 451.

@dlmcshan It sounds like you may need some extra help with motor calibration still. Assuming you purchased a full kit from FarmBot, Inc., you may request direct email support from our staff by emailing Please have your order number ready for proof of purchase. Alternatively, you may provide the email address used to purchase the device.