I ran the calibration routine and recorded 2,500 cycles. The number seemed excessive given the speed and that it would have taken 25K spins, and I should have had less than one thousand. I added an RPM column to the spreadsheet, and it said that a 60-microsecond rotation would have been 1000 rpm, which was preposterous. I will get a tachometer. The minimum cycle time was too low to be genuine readings, so there must be some jitter, and if that's true, I can't use this sensor.
I reprogrammed the sketch to ignore any pulse less than 6000 microseconds. During these readings, the motor was jittery, like the ESC occasionally got zero-speed commands. I adjusted the hall effect module's potentiometer and recorded 575 cycles, and this time the RPM calculation showed 500 revolutions per minute, which seemed reasonable. The spreadsheet program calculated the value from the average pulse time, but the readings were still unstable.
Potentiometer adjustment
The subsequent readings were similar, but my minimum time was always between 6008 and 6040 microseconds with an average of 6.8 KRPM. The old RPM was probably inaccurate, but I'll use a tachometer next time to confirm.
I turned on the bit to show every rotation time in manual mode, and when I ran the motor slowly, there was tons of noise, but when I commanded higher speeds, the plot smoothed out. There is a wide disparity between alternating readings, which suggests the sensor detects when the magnet comes into range, then falsely triggers when it leaves. I hope to program around this or dampen the magnetic field to improve my accuracy. I will ignore the slow speeds in my calibration routine.
Predictable modulations as I changed speed
The rest of the posts for this project have been arranged by date.
First time here?
Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7
Completed projects from year 8
Disclaimer for http://24hourengineer.blogspot.com and 24HourEngineer.com
This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.
All information on this blog, or linked by this blog, is not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property, or similar, is the responsibility of those involved in the replication.
All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.
Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.
This blog, including pictures and text, is copyright to Brian McEvoy.
2022-11-15
I reprogrammed the sketch to ignore any pulse less than 6000 microseconds. During these readings, the motor was jittery, like the ESC occasionally got zero-speed commands. I adjusted the hall effect module's potentiometer and recorded 575 cycles, and this time the RPM calculation showed 500 revolutions per minute, which seemed reasonable. The spreadsheet program calculated the value from the average pulse time, but the readings were still unstable.
The subsequent readings were similar, but my minimum time was always between 6008 and 6040 microseconds with an average of 6.8 KRPM. The old RPM was probably inaccurate, but I'll use a tachometer next time to confirm.
I turned on the bit to show every rotation time in manual mode, and when I ran the motor slowly, there was tons of noise, but when I commanded higher speeds, the plot smoothed out. There is a wide disparity between alternating readings, which suggests the sensor detects when the magnet comes into range, then falsely triggers when it leaves. I hope to program around this or dampen the magnetic field to improve my accuracy. I will ignore the slow speeds in my calibration routine.
The rest of the posts for this project have been arranged by date.
First time here?
Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7
Completed projects from year 8
Disclaimer for http://24hourengineer.blogspot.com and 24HourEngineer.com
This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.
All information on this blog, or linked by this blog, is not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property, or similar, is the responsibility of those involved in the replication.
All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.
Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.
This blog, including pictures and text, is copyright to Brian McEvoy.
2022-11-15
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