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FLL EV3 Robot

This blog post is about our current EV3 robot we're planning to use in the 2023/2024 FLL competition. Some features: 2 large motors for steering. 2 medium motors for attachments.  2 colour sensors for picking up the white and black lines, also used for line squaring. 1 gyro sensor. To enable attachments to be changed as quickly as possible we're using gravity to keep the gears connected, i.e. you don't need to fasten anything to the robot. Every attachment has 2x 12 tooth double bevel gear (part 32270) which comes in contact with the 2x 20 tooth double bevel gears (part 32269) on the robot. The medium motors are horizontally aligned on the robots, but we use 12 tooth double bevel gears to convert that to vertical alignments. These in turn are connected to 20 tooth double bevel gears, and the attachments in turn connect to these 20 tooth double bevel gears with their 12 tooth double bevel gears.  The complete robot is modelled in Bricklink Studio 2 . You can download the rob...
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HP Laptop Battery calibration

My HP 510 laptop's battery is supposed to keep the laptop running for 2 hours. However it lasted only 1 hour (I bought it new), and 1.5 years later I got about 15 minutes. The laptop runs WinXP Home.

Reading some pages on the HP battery check utility, I've decided to reclaibrate my battery. This means charging the battery to 100%, set the power saving setting to "Always on", and keep the laptop running until it eventually dies. 

For the first 15 minutes, the power level dropped at a constant rate, until it hit about 5%. Then it stayed for almost 30 minutes at 5%, and then died quickly.

Running the laptop on AC power, I saw that the HP battery check utility reported a different battery level as Windows. After a restart both reported the same level.

This means Windows does not always report the right battery level, and this is why you need to calibrate your laptop's battery every couple of months.


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