This is for an add on board designed for the flipper zero. It allows the flipper zero to send RS-232 commands through it's USB to UART mode. You can have the raw pcb made at OSHPARK
The RS-232 is sent via the 3.5mm TRS Headphone jack. You will need an adapter cable to go from 3.5mm to DB9, RJ12, or RJ45 LINK
BOM for Flipper zero add on board
5 x 0805 SMD 100nf ceramic capacitor (Generic common part) Designator Footprint: C1 - C5
1 x TRS headphone jack (part number PJ-307N5) Designator Footprint: CN1
2 x 1206 SMD 1k resistor Designator Footprint: R1, R2
2 x 0805 SMD LEDs (Generic 20ma ≈2.5v) Designator Footprint: TX, RX
1 x SOP16 MAX3232CDR (most max232 sop16 chips will work but MAX3232 works nicely with 3.3v and uses less power. Check datasheet for Capacitor values if you change the ic) Designator Footprint: MAX
2.54mm pitch right angle pin header male. One 8 pin one 10 pin.
SCHEMATIC:
