Introduction - If you have any usage issues, please Google them yourself
(1) the completion of the keyboard, Seven-Segment LED display, buzzer, A/D data acquisition, the self-test program design watchdog (2) the use of dial, the keyboard and the Seven-Segment LED displays, the realization of arbitrary-19999 to+19999 5 sets of digital input, storage, read out with the necessary protective measures. Tip: master key 74HC245, Seven-Segment LED displays, and programming circuit 25045.