Collaborate Disseminate
[Trent M. Wyatt]’s CPUVolt library provides a fast way to measure voltage using no external components, and no I/O pin. It only applies to certain microcontrollers, but he provides example …read more Continue reading Arduino Measures Remaining Battery Power With Zero Components, No I/O Pin
We’ve all seen the little USB power meters that have become popular since nearly every portable device has adopted some variation of USB for charging. Placed between the power source and the device under test, they allow you to see voltage and current in real time. Perfect for determining how long you’ll be able to run a USB powered device on batteries, or finding out if a USB power supply has enough current to do the business.
[Jonas Persson] liked the idea of these cheap little gadgets, but wanted something a bit more scientific. His design, which he refers to …read more
Continue reading Open Hardware Board For Robust USB Power Monitoring
Some time ago [Xose Pérez] got interested in generating a notification when his washer had completed a cycle, and now with added features like reporting power usage and cost, he’s put it all together into a Node-Red node that makes it easy to modify or integrate with other projects.
[Xose] started this journey with a Laundry Monitor he created that effectively used cheap hardware (and his own firmware) to monitor his washing machine’s current usage. That sensor was used as the basis for sending notifications informing him whenever the appliance’s cycle was done. Since then, he has continued to take …read more
Continue reading Adding Energy Use and Cost to “Laundry Done” Notifications
It seems that one can buy cheap power meters online and, well, that’s it. They work just fine, but to use them for anything else (like datalogging or control or…) they need a bit more work. The good news is that [Thomas Scherrer], alias [OZ2CPU], just did that reverse engineering work for us.
Inside these budget power meters, you’ll find an LCD driver, a power-monitoring chip, and an STM32F030, which is a low-cost ARM Cortex M0 chip that’s fun to play with on its own. [Thomas] traced out the SPI lines that the power-monitoring chip uses to talk to the …read more
Continue reading Put a Reverse Engineered Power Meter in Your Toolkit