From 6cda8e027715114e826ac550bc24cab66e12667e Mon Sep 17 00:00:00 2001
From: Neil Gershenfeld <gersh@cba.mit.edu>
Date: Sun, 4 Apr 2021 13:08:12 -0400
Subject: [PATCH] add termios
---
comm/termios/ring.termios.c | 60 +++++++++++++++++++++++++++++++++++++
index.html | 8 +++++
2 files changed, 68 insertions(+)
create mode 100644 comm/termios/ring.termios.c
diff --git a/comm/termios/ring.termios.c b/comm/termios/ring.termios.c
new file mode 100644
index 0000000..2eb49b0
--- /dev/null
+++ b/comm/termios/ring.termios.c
@@ -0,0 +1,60 @@
+//
+// ring.termios.c
+//
+// termios communication ring test
+//
+// Neil Gershenfeld 4/4/21
+//
+// This work may be reproduced, modified, distributed,
+// performed, and displayed for any purpose, but must
+// acknowledge this project. Copyright is retained and
+// must be preserved. The work is provided as is; no
+// warranty is provided, and users accept all liability.
+//
+#include <stdio.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/time.h>
+//
+#define nloop 100
+//
+int main(int argc,char *argv[]) {
+ if (argc != 3) {
+ printf("command line: ring.termios serial_port port_speed\n");
+ return -1;
+ }
+ int speed = atoi(argv[2]);
+ int port = open(argv[1],O_RDWR|O_NOCTTY|O_NDELAY);
+ fcntl(port,F_SETFL,0);
+ struct termios term;
+ tcgetattr(port,&term);
+ term.c_cflag &= ~(PARENB|CSTOPB|CSIZE|CRTSCTS);
+ term.c_cflag |= (CS8|CREAD|CLOCAL);
+ term.c_lflag &= ~(ICANON|ECHO|ECHOE|ECHONL|ISIG);
+ term.c_iflag &= ~(IXON|IXOFF|IXANY|IGNBRK|BRKINT
+ |PARMRK|ISTRIP|INLCR|IGNCR|ICRNL);
+ term.c_oflag &= ~(OPOST|ONLCR);
+ term.c_cc[VTIME] = 0;
+ term.c_cc[VMIN] = 1;
+ cfsetispeed(&term,speed);
+ cfsetospeed(&term,speed);
+ tcsetattr(port,TCSANOW,&term);
+ unsigned char chr = 0;
+ struct timeval start,end;
+ tcflush(port,TCIOFLUSH);
+ gettimeofday(&start,NULL);
+ for (int i = 0; i < nloop; ++i) {
+ while (1) {
+ write(port,&chr,1);
+ read(port,&chr,1);
+ if (chr == 0)
+ break;
+ }
+ }
+ gettimeofday(&end,NULL);
+ printf("byte ring cycles per second: %6.3g\n",nloop*256/((end.tv_sec+end.tv_usec/1e6)-(start.tv_sec+start.tv_usec/1e6)));
+ close(port);
+ return 0;
+ }
diff --git a/index.html b/index.html
index 93b393a..0649d41 100644
--- a/index.html
+++ b/index.html
@@ -189,6 +189,14 @@ The communication test measures how quickly two nodes can exchange messages; thi
<th>date</th>
</tr>
+<tr>
+<td>0.010</td>
+<td><a href=comm/termios/ring.termios.c>i7-8700T, C, termios</a></td>
+<td>USB 2.1</td>
+<td><a href=comm/SerialUSB/ring.SerialUSB.ino>ATSAMD11C, Arduino, SerialUSB</a></td>
+<td>April2021</td>
+</tr>
+
<tr>
<td>0.007</td>
<td><a href=comm/pySerial/ring.pySerial.py>i7-8700T, Python, pySerial</a></td>
--
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