get keyboard input contiki - contiki

Question

I want to know how can I get a keyboard input in contiki os.
I already tried getchar(),getch(),scanf(),gets() and none worked, so I want to know if somebody can help me.

Answer 1

getchar,getch,scanf,gets are sort of POSIX things that read from files (e.g. stdin) --- these don't exist in Contiki (all though you could probably use them with the native platform).
So the first question to ask is what platform are you using and what do you mean by "keyboard". If keyboard means typing characters that are sent via a serial port from a computer then you have to know where they are received on the thing running Contiki. A typical arrangement is to receive characters on a uart, say, uart1.
In this case, contiki uses a callback such as uart1_input_handler that will be defined by the application. Platform main loops will check if there are characters to send to the input_handler and then check that an input_handler is defined. If so, will call something like uart1_input_handler(c).
You can see this code for the various platforms by grepping for uart1_input_handler:
platform/redbee-econotag/contiki-mc1322x-main.c: uart1_input_handler(uart1_getc());
cpu/msp430/dev/uart1x.c: if(uart1_input_handler(c)) {
cpu/stm32w108/dev/uart1.c: uart1_input_handler(c);
etc...
Some examples that register an input handler and process the characters:
example/shell:
/* set up the shell */
uart1_set_input(serial_line_input_byte);
serial_line_init();
serial_shell_init();
slip, in examples/ipv6/rpl-border-router/slip-bridge.c
slip_set_input_callback(slip_input_callback);
My guess for what you want to do would be to start with the shell examples and try to get those working.

Answer 2

The example cited below is from the Wiki pages of contiki on github. It demonstrates how the contiki specific mechanism for serial input works. Like mariano mentioned above that a callback has to be defined for the serial drivers specific to the platform you are using. I have used for ex. "rs232_set_input(RS232_PORT_0, serial_line_input_byte) ; " for my atmega128 MCU. The serial i/o drivers use this callback mechanism to post input characters to the "serial_line_process" defined in serial-line.c file. This process then broadcasts the serial_line_event_message to all processes along with the data read on the serial line. A process like the eg. stated below, can catch this event and process the input as per the requirements.
The callback mentioned above is defined in $(CONTIKI)/core/dev/serial-line.c. Check that out.
Once you initialise it using serial_line_init(), you are good to go.
#include "contiki.h"
#include "dev/serial-line.h"
#include <stdio.h>
PROCESS(test_serial, "Serial line test process");
AUTOSTART_PROCESSES(&test_serial);
PROCESS_THREAD(test_serial, ev, data)
{
PROCESS_BEGIN();
for(;;) {
PROCESS_YIELD();
if(ev == serial_line_event_message) {
printf("received line: %s\n", (char *)data);
}
}
PROCESS_END();
}

Answer 3

I assume you use COOJA (or maybe you connected a keyboard to your device so my answer will not be correct).
COOJA is an emulator, not a simulator.
If you want a responsive design, use the sensor button (on sky platform for example)
SENSORS_ACTIVATE(button_sensor);
/* Wait until we get a sensor event with the button sensor as data. */
PROCESS_WAIT_EVENT_UNTIL(ev == sensors_event &&
data == &button_sensor);
Hope it helped.