RS232 interface circuit diagram highlights

Seiko original 32.768KHZ 3215 (3.2*1.5mm) 12.5P

Figure 1 AT90S2313 MAX232 AVR microcontroller serial port circuit diagram

Figure 2 RS232 to RS485 interface circuit diagram (HIN232CP SN75LBC184)

Figure 3 RS232 interface circuit diagram