void main (void) {
nx_systick_install_scheduler(security_hook);
nx_rs485_init();
while (1) {
lock = 1;
nx_rs485_send(out_buffer, sizeof(out_buffer), send_callback);
while (lock) {
nx_systick_wait_ms(1000);
}
}
}
void main() {
/* We'll use this buffer to read data from the RS485 bus. This needs
* to be volatile because it gets modified outside of the main code
* path (in interrupt handlers).
*/
U8 buffer_hello[12] = "Hello world";
U8 buffer_empty[12] = {0};
/* Install our emergency shutdown hook. See above for details. */
nx_systick_install_scheduler(shutdown_hook);
/* Initialize the RS485 driver for communication at 9600 bits per
* second with no timeout. If you need special communication modes
* (number of start/stop bits, parity checks...), you can specify an
* explicit mode register value.
*/
nx_rs485_init(RS485_BR_9600, 0, 0, FALSE);
for (int i = 0; i < 10; ++i) {
/* This is just to alternate between sending two different
* messages. One time we send "hello world", the other an empty
* string.
*/
U8 *buffer = (i % 2 == 0) ? buffer_hello : buffer_empty;
/* Display what we are transmitting, for the record */
nx_display_clear();
nx_display_string("Iteration ");
nx_display_uint(i+1);
nx_display_string("\n");
nx_display_string((char*)buffer);
/* Wait a bit before actually sending, to get a nice obvious
* delayed transmission effect.
*/
nx_systick_wait_ms(1000);
/* Try to write 12 bytes to the RS485 bus. This call merely
* instructs the RS485 driver to start writing data, and returns
* immediately.
*
* Once the read of all 12 bytes is complete, the given callback
* function will be called, with a status value, indicating
* whether or not there was an error.
*/
nx_rs485_send(buffer, sizeof(buffer), send_callback);
/* Since the above function returns immediately, we need a way to
* wait for the receive to complete. How you do this depends on
* how you want your application kernel to work, but in this case,
* we'll just block on our spinlock, until the callback unlocks it
* after the write completes.
*/
nx_spinlock_acquire(&lock);
/* Wait before transmitting the next round, again purely for
* effect.
*/
nx_systick_wait_ms(1000);
}
}
