08-16-2017, 11:47 PM
(08-16-2017, 08:28 AM)fire219 Wrote: Technically you could try to time it blind, but unless you already know how the boot output over serial looks you are unlikely to get it right.
Yesterday I tried to it blind.
When I removed the jumper 3 seconds after turning on the power, writing the image succeeded.
However, this method may be dangerous. Then I will try to it by using a serial adapter (CP2104) tonight.