Skip to content

Latest commit

 

History

History
58 lines (45 loc) · 1.9 KB

README.md

File metadata and controls

58 lines (45 loc) · 1.9 KB
Raw

SioFus

Simple Input Output From USB to Serial adapter is a short code designed to read and write digital signals to/from the real world. Based on the highlighted PINs of the following list, we will be able to setup 4 digital inputs and 2 digital outputs just using a cheap USB2Serial adapter

USB PIN # Name
1 USB VCC
2 Data -
3 Data +
4 Ground -
Serial (DB9) PIN # Name
1 DCD (Carrier Detect)
2 RxD (Receive Data)
3 TxD (Transmit Data)
4 DTR (Data Terminal Ready)
5 SG (Signal Ground)
6 DSR (Data Set Ready)
7 RTS (Request To Send)
8 CTS (Clear To Send)
9 RI (Ring Indicator)

Launch the process

./siofus -p /dev/ttyUSB0

Usage as OUTPUT

We will be able to control DTR and RTS PINS on our adapter. The process will be listening (NONBLOCK) for input on the stdin:

  • if key "a" is pressed send +5V to PIN4 (DTR)
  • if key "s" is pressed send -5V to PIN4 (DTR)
  • if key "d" is pressed send +5V to PIN7 (RTS)
  • if key "f" is pressed send -5V to PIN7 (RTS)

You would get a current around 0.05A

Usage as INPUT

The idea is being able to tell weather a circuit is open or closed. For this purpouse, we will be using USB PIN 1 as the VCC source. The process will be able to tell when the circuit is closed or opened. These are then PINS used in the Serial conector:

  • PIN1 (DCD) : INPUT0
  • PIN6 (DSR) : INPUT1
  • PIN8 (CTS) : INPUT2
  • PIN9 (RNG) : INPUT3

The process will be able to tell to the stdout when a PIN has been closed or opened. For example, when someone connect USB PIN1 to Serail PIN6 (DSR), SioFus will simple write to stdout "#C1#"; when the connection is released, it will write "#O1#".

Compile

gcc -o siofus siofus.c

Version

0.0.1