king.oslo

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  1. Hello there. At present I power my Tinker Board S with a bench power supply set to 5.25V. The power supply has 10A current limiter. I measure the voltage at the GPIO pins using a 6.5 digit multimeter (in cal). The micro usb cord is 1.2 meters (4 feet). When the board is running in tinker os at idle, it is drawing 500mA, and i read 5.00V on the GPIO. But when I load the CPU using sysbench the current spikes to 1.6A, and the voltage measured on the GPIO drops to 4.45V. I measured that the micro USB cable is 0.37Ohm resistance, so about 0.55V of that power drop is due to the micro usb cable. That means all of the voltage drop is not due to the power cord, and the voltage onboard at the micro usb connector is exactly 4.6V, and I have some questions: 0. What is causing of the power drop of 0.25V measured on the GPIO pins relative to onboard at the micro usb connector? This is a cause for concern if I want to attempt to power the board using the GPIO. 1. In the thread below, TonyMac32 propose to drive the tinker board using the GPIO pins directly. Are there any other viable options? 2. I get a low voltage warning in the OS when I start loading the CPU with sysbench, and I read this thread: Since this is not a plug and play solution to the problem, what are ASUS recommendation to deal with the voltage drop in the usb cable? 3. What is the absolute maximum voltage rating of the tinker board s? I am not asking about the USB maximum voltage specification, I am asking what the onboard hardware has as maximum rating. Thank you for your time. Kind regards, Marius