Does exist an apk for android 4.0 that is able to read and write data on RS485 connection?
I'm using a noise sensor which has 4 output pins (485A, 485B, V+, V-), the device where android is installed has a female RS485 port and i'm conneting directly that 4 pins to the port. I have already used apps like Serial Communication RS232 and Serial Communication by STMicroelectronics but both of them need to be connected via OTG Cable.
When i run any of these applications, no device is detected, so i'm probably connecting the wires wrongly but i honestly i don't know what is happening.
Finally I found the apk that allowed me to perform this whole procedure. It is android-serialport-api. To make it work, I just needed to check to port that RS485 was using (/dev/ttymxcs1), choose it and select the baudrate.
However, Is mandatory to use an on-screen keyboard (OSK) since i was using an external one and i wasn't able to send data because the "Enter" key was a line break.
On the other hand, it can also be an alternative to use an android-terminal-emulator but since the baudrate can't be selected, you would need an external package like screen or stty (in my case i had no internet connectivity so i couldn't download them)
SCREEN
# sudo apt-get install screen
# screen /dev/ttymxcs1 4800
STTY
# sudo apt-get coreutils
# stty -F /dev/ttymxcs1 4800