The goalEnable your MR3020 OpenWrt router to communicate with microcontrolers via RS232 port in both ways.
- TP-LINK MR3020 router flashed with OpenWrt
- pin connectors
- signal cable
DescriptionRecently I needed another router for Openwrt, my previous MR3420 went down, I accidentally burn him :)
This one is a beauty, it's small and has capabilities that fit my needs: CPU:Atheros AR7240@400MHz, Ram:32M, Flash:4M, USB 2.0 and of course most important for me - RS232 port.
|Board with soldered pins for RS232.|
|RS232 connector with cable. TX, RX, GND, VCC|
As a default, RS232 port is used for debug kernel messages (you need to recompile the kernel to disable that behaviour), furthermore there is a console running on this port, so it need to be turned off.
I'm to lazy to recompile kernel, so I just disabled serial console. Debug kernel messages was still on serial port, so on the other side of the wire (microcontroler) I wrote a program which uses my custom protocol with pseudo data validation. It's working for now, so I don't bother anymore, of course MCU has more work to do, but who cares.
Default port path from device is /dev/ttyATH0, you can use it the same way, as standard linux port e.g. screen /dev/ttyATH0 9600.
|My ugly custom connector|