Serial_interrupts - Test

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Dr. Pucher / Mbed 2 deprecated Serial_interrupts

Test

main.cpp@0:023c5cda6102, 2010-11-16 (annotated)

Committer:: 4180_1
Date:: Tue Nov 16 15:00:30 2010 +0000
Revision:: 0:023c5cda6102
Child:: 2:f026b40fadb1

Who changed what in which revision?

User	Revision	Line number	New contents of line
4180_1	0:023c5cda6102	1
4180_1	0:023c5cda6102	2	#include "mbed.h"
4180_1	0:023c5cda6102	3	// Serial TX & RX interrupt loopback test using formatted IO - sprintf and sscanf
4180_1	0:023c5cda6102	4	// Connect TX to RX (p9 to p10)
4180_1	0:023c5cda6102	5	// or can also use USB and type back in the number printed out in a terminal window
4180_1	0:023c5cda6102	6	// Sends out ASCII numbers in a loop and reads them back
4180_1	0:023c5cda6102	7	// If not the same number LED4 goes on
4180_1	0:023c5cda6102	8	// LED1 and LED2 indicate RX and TX interrupt routine activity
4180_1	0:023c5cda6102	9	// LED3 changing indicate main loop running
4180_1	0:023c5cda6102	10
4180_1	0:023c5cda6102	11
4180_1	0:023c5cda6102	12	Serial device(p9, p10); // tx, rx
4180_1	0:023c5cda6102	13	// Can also use USB and type back in the number printed out in a terminal window
4180_1	0:023c5cda6102	14	// Serial monitor_device(USBTX, USBRX);
4180_1	0:023c5cda6102	15	DigitalOut led1(LED1);
4180_1	0:023c5cda6102	16	DigitalOut led2(LED2);
4180_1	0:023c5cda6102	17	DigitalOut led3(LED3);
4180_1	0:023c5cda6102	18	DigitalOut led4(LED4);
4180_1	0:023c5cda6102	19
4180_1	0:023c5cda6102	20
4180_1	0:023c5cda6102	21	void Tx_interrupt();
4180_1	0:023c5cda6102	22	void Rx_interrupt();
4180_1	0:023c5cda6102	23	void send_line();
4180_1	0:023c5cda6102	24	void read_line();
4180_1	0:023c5cda6102	25
4180_1	0:023c5cda6102	26
4180_1	0:023c5cda6102	27	// Circular buffers for serial TX and RX data - used by interrupt routines
4180_1	0:023c5cda6102	28	const int buffer_size = 255;
4180_1	0:023c5cda6102	29	// might need to increase buffer size for high baud rates
4180_1	0:023c5cda6102	30	char tx_buffer[buffer_size];
4180_1	0:023c5cda6102	31	char rx_buffer[buffer_size];
4180_1	0:023c5cda6102	32	// Circular buffer pointers
4180_1	0:023c5cda6102	33	// volatile makes read-modify-write atomic
4180_1	0:023c5cda6102	34	volatile int tx_in=0;
4180_1	0:023c5cda6102	35	volatile int tx_out=0;
4180_1	0:023c5cda6102	36	volatile int rx_in=0;
4180_1	0:023c5cda6102	37	volatile int rx_out=0;
4180_1	0:023c5cda6102	38	// Line buffers for sprintf and sscanf
4180_1	0:023c5cda6102	39	char tx_line[80];
4180_1	0:023c5cda6102	40	char rx_line[80];
4180_1	0:023c5cda6102	41
4180_1	0:023c5cda6102	42	// main test program
4180_1	0:023c5cda6102	43	int main() {
4180_1	0:023c5cda6102	44	int i=0;
4180_1	0:023c5cda6102	45	int rx_i=0;
4180_1	0:023c5cda6102	46	device.baud(9600);
4180_1	0:023c5cda6102	47
4180_1	0:023c5cda6102	48	// Setup a serial interrupt function to receive data
4180_1	0:023c5cda6102	49	device.attach(&Rx_interrupt, Serial::RxIrq);
4180_1	0:023c5cda6102	50	// Setup a serial interrupt function to transmit data
4180_1	0:023c5cda6102	51	device.attach(&Tx_interrupt, Serial::TxIrq);
4180_1	0:023c5cda6102	52
4180_1	0:023c5cda6102	53	// Formatted IO test using send and receive serial interrupts
4180_1	0:023c5cda6102	54	// with sprintf and sscanf
4180_1	0:023c5cda6102	55	while (1) {
4180_1	0:023c5cda6102	56	// Loop to generate different test values - send value in hex, decimal, and octal and then read back
4180_1	0:023c5cda6102	57	for (i=0; i<0xFFFF; i++) {
4180_1	0:023c5cda6102	58	led3=1;
4180_1	0:023c5cda6102	59	// Print ASCII number to tx line buffer in hex
4180_1	0:023c5cda6102	60	sprintf(tx_line,"%x\r\n",i);
4180_1	0:023c5cda6102	61	// Copy tx line buffer to large tx buffer for tx interrupt routine
4180_1	0:023c5cda6102	62	send_line();
4180_1	0:023c5cda6102	63	// Print ASCII number to tx line buffer in decimal
4180_1	0:023c5cda6102	64	sprintf(tx_line,"%d\r\n",i);
4180_1	0:023c5cda6102	65	// Copy tx line buffer to large tx buffer for tx interrupt routine
4180_1	0:023c5cda6102	66	send_line();
4180_1	0:023c5cda6102	67	// Print ASCII number to tx line buffer in octal
4180_1	0:023c5cda6102	68	sprintf(tx_line,"%o\r\n",i);
4180_1	0:023c5cda6102	69	// Copy tx line buffer to large tx buffer for tx interrupt routine
4180_1	0:023c5cda6102	70	send_line();
4180_1	0:023c5cda6102	71	led3=0;
4180_1	0:023c5cda6102	72	// Read a line from the large rx buffer from rx interrupt routine
4180_1	0:023c5cda6102	73	read_line();
4180_1	0:023c5cda6102	74	// Read ASCII number from rx line buffer
4180_1	0:023c5cda6102	75	sscanf(rx_line,"%x",&rx_i);
4180_1	0:023c5cda6102	76	// Check that numbers are the same
4180_1	0:023c5cda6102	77	if (i != rx_i) led4=1;
4180_1	0:023c5cda6102	78	// Read a line from the large rx buffer from rx interrupt routine
4180_1	0:023c5cda6102	79	read_line();
4180_1	0:023c5cda6102	80	// Read ASCII number from rx line buffer
4180_1	0:023c5cda6102	81	sscanf(rx_line,"%d",&rx_i);
4180_1	0:023c5cda6102	82	// Check that numbers are the same
4180_1	0:023c5cda6102	83	if (i != rx_i) led4=1;
4180_1	0:023c5cda6102	84	// Read a line from the large rx buffer from rx interrupt routine
4180_1	0:023c5cda6102	85	read_line();
4180_1	0:023c5cda6102	86	// Read ASCII number from rx line buffer
4180_1	0:023c5cda6102	87	sscanf(rx_line,"%o",&rx_i);
4180_1	0:023c5cda6102	88	// Check that numbers are the same
4180_1	0:023c5cda6102	89	if (i != rx_i) led4=1;
4180_1	0:023c5cda6102	90	}
4180_1	0:023c5cda6102	91	}
4180_1	0:023c5cda6102	92	}
4180_1	0:023c5cda6102	93
4180_1	0:023c5cda6102	94	// Copy tx line buffer to large tx buffer for tx interrupt routine
4180_1	0:023c5cda6102	95	void send_line() {
4180_1	0:023c5cda6102	96	int i;
4180_1	0:023c5cda6102	97	char temp_char;
4180_1	0:023c5cda6102	98	bool empty;
4180_1	0:023c5cda6102	99	i = 0;
4180_1	0:023c5cda6102	100	// Start Critical Section - don't interrupt while changing global buffer variables
4180_1	0:023c5cda6102	101	NVIC_DisableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	102	empty = (tx_in == tx_out);
4180_1	0:023c5cda6102	103	while ((i==0) \|\| (tx_line[i-1] != '\n')) {
4180_1	0:023c5cda6102	104	// Wait if buffer full
4180_1	0:023c5cda6102	105	if (((tx_in + 1) % buffer_size) == tx_out) {
4180_1	0:023c5cda6102	106	// End Critical Section - need to let interrupt routine empty buffer by sending
4180_1	0:023c5cda6102	107	NVIC_EnableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	108	while (((tx_in + 1) % buffer_size) == tx_out) {
4180_1	0:023c5cda6102	109	}
4180_1	0:023c5cda6102	110	// Start Critical Section - don't interrupt while changing global buffer variables
4180_1	0:023c5cda6102	111	NVIC_DisableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	112	}
4180_1	0:023c5cda6102	113	tx_buffer[tx_in] = tx_line[i];
4180_1	0:023c5cda6102	114	i++;
4180_1	0:023c5cda6102	115	tx_in = (tx_in + 1) % buffer_size;
4180_1	0:023c5cda6102	116	}
4180_1	0:023c5cda6102	117	if (device.writeable() && (empty)) {
4180_1	0:023c5cda6102	118	temp_char = tx_buffer[tx_out];
4180_1	0:023c5cda6102	119	tx_out = (tx_out + 1) % buffer_size;
4180_1	0:023c5cda6102	120	// Send first character to start tx interrupts, if stopped
4180_1	0:023c5cda6102	121	device.putc(temp_char);
4180_1	0:023c5cda6102	122	}
4180_1	0:023c5cda6102	123	// End Critical Section
4180_1	0:023c5cda6102	124	NVIC_EnableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	125	return;
4180_1	0:023c5cda6102	126	}
4180_1	0:023c5cda6102	127
4180_1	0:023c5cda6102	128	// Read a line from the large rx buffer from rx interrupt routine
4180_1	0:023c5cda6102	129	void read_line() {
4180_1	0:023c5cda6102	130	int i;
4180_1	0:023c5cda6102	131	i = 0;
4180_1	0:023c5cda6102	132	// Start Critical Section - don't interrupt while changing global buffer variables
4180_1	0:023c5cda6102	133	NVIC_DisableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	134	// Loop reading rx buffer characters until end of line character
4180_1	0:023c5cda6102	135	while ((i==0) \|\| (rx_line[i-1] != '\r')) {
4180_1	0:023c5cda6102	136	// Wait if buffer empty
4180_1	0:023c5cda6102	137	if (rx_in == rx_out) {
4180_1	0:023c5cda6102	138	// End Critical Section - need to allow rx interrupt to get new characters for buffer
4180_1	0:023c5cda6102	139	NVIC_EnableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	140	while (rx_in == rx_out) {
4180_1	0:023c5cda6102	141	}
4180_1	0:023c5cda6102	142	// Start Critical Section - don't interrupt while changing global buffer variables
4180_1	0:023c5cda6102	143	NVIC_DisableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	144	}
4180_1	0:023c5cda6102	145	rx_line[i] = rx_buffer[rx_out];
4180_1	0:023c5cda6102	146	i++;
4180_1	0:023c5cda6102	147	rx_out = (rx_out + 1) % buffer_size;
4180_1	0:023c5cda6102	148	}
4180_1	0:023c5cda6102	149	rx_line[i-1] = 0;
4180_1	0:023c5cda6102	150	// End Critical Section
4180_1	0:023c5cda6102	151	NVIC_EnableIRQ(UART1_IRQn);
4180_1	0:023c5cda6102	152	return;
4180_1	0:023c5cda6102	153	}
4180_1	0:023c5cda6102	154
4180_1	0:023c5cda6102	155	// Interupt Routine to read in data from serial port
4180_1	0:023c5cda6102	156	void Rx_interrupt() {
4180_1	0:023c5cda6102	157	led1=1;
4180_1	0:023c5cda6102	158	// Loop just in case more than one character is in UART's receive FIFO buffer
4180_1	0:023c5cda6102	159	// Stop if buffer full
4180_1	0:023c5cda6102	160	while ((device.readable()) \|\| (((rx_in + 1) % buffer_size) == rx_out)) {
4180_1	0:023c5cda6102	161	rx_buffer[rx_in] = device.getc();
4180_1	0:023c5cda6102	162	// Uncomment to Echo to USB serial to watch data flow
4180_1	0:023c5cda6102	163	// monitor_device.putc(rx_buffer[rx_in]);
4180_1	0:023c5cda6102	164	rx_in = (rx_in + 1) % buffer_size;
4180_1	0:023c5cda6102	165	}
4180_1	0:023c5cda6102	166	led1=0;
4180_1	0:023c5cda6102	167	return;
4180_1	0:023c5cda6102	168	}
4180_1	0:023c5cda6102	169
4180_1	0:023c5cda6102	170	// Interupt Routine to write out data to serial port
4180_1	0:023c5cda6102	171	void Tx_interrupt() {
4180_1	0:023c5cda6102	172	led2=1;
4180_1	0:023c5cda6102	173	// Loop to fill more than one character in UART's transmit FIFO buffer
4180_1	0:023c5cda6102	174	// Stop if buffer empty
4180_1	0:023c5cda6102	175	while ((device.writeable()) && (tx_in != tx_out)) {
4180_1	0:023c5cda6102	176	device.putc(tx_buffer[tx_out]);
4180_1	0:023c5cda6102	177	tx_out = (tx_out + 1) % buffer_size;
4180_1	0:023c5cda6102	178	}
4180_1	0:023c5cda6102	179	led2=0;
4180_1	0:023c5cda6102	180	return;
4180_1	0:023c5cda6102	181	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	15 Nov 2018
Imports:	4
Forks:	0
Commits:	3
Dependents:	0
Dependencies:	1
Followers:	1

main.cpp@0:023c5cda6102, 2010-11-16 (annotated)

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