voltage reg
C1
VS1
C4
Capacitance
22uF
CD
RS
er-cd
C2
R1
Resistance
10kΩ
CS
reset
VS2
cd-dr
rs232tx
C3
Capacitance
1µF
rs232rx
R2
Resistance
10kΩ
cs-rs
ER
DR
ESP-01
usb power
rs232 converter