The bases and key caps were nearly finished, so I assembled the basic light circuit with an Arduino Micro. I first put the LED filament between an IO point and the 3.3V reference to run a BLINK example. The light was overwhelmingly bright. I reconnected it to a PWM pin so I could dim it programmatically and lower it enough to be comfortable, giving me one good option. Next, I connected the pin between GND and the PWM pin so it would use 5V, and the max brightness was too high again, but I could easily lower the duty cycle and have control. Lastly, I added 100Ω resistors in series with the light. I expected to need 1-watt components, but my 1/4W resistors did not get warm. 300Ω produced a comfortable light intensity, and I could dim it with full resolution. I will use IO expanders for the lights and pushbuttons, so I should know enough to draw the complete circuit.
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
Completed projects from year 9
Completed projects from year 10
Completed projects from year 11
Completed projects from year 12
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.
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This blog, including pictures and text, is copyright to Brian McEvoy.
2026-02-19
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| Arduino testing with a 3.3V LED filament |
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
Completed projects from year 9
Completed projects from year 10
Completed projects from year 11
Completed projects from year 12
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.
2026-02-19
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