With no intention to be sophomoric... in any communications from-to link, rare is the case where the receiver can always keep-up (accept all) arriving data without coordination with the sender. So an OSI stack of protocols is used (like TCP) or simpler, a header + data packet or frame is created by the sender. Header contains data length and an ascension number to detect duplicate and lost packets (data frames). And an agreement that the sender will stop sending after 1-n frames and wait for the receiver to acknowledge receipt. The ACK says "ready for more". No ack at all can cause the sender to timeout and retransmit. Apologies if the OP knows well these basics.
#include <Arduino.h>
#include <cstdio>
void setup()
{
Serial.begin(9600); // USB is always 12 Mbit/sec
while ( !Serial || millis() < 10000); //wait for user to start up serial listener...
}
char datastring[100];
void fillbuffer(uint32_t iterationCount, uint32_t timeStart, uint32_t timeNow, uint32_t timeDelta)
{
sprintf(datastring,"%08lu\n%010lu\n%08lu\n%08lu\n", iterationCount, timeNow - timeStart, timeDelta, (uint32_t) Serial.availableForWrite() );
sprintf(&datastring[strlen(datastring)], "%04d\n", 5+8+strlen(datastring)); //account for header, footer, and this message itself
}
void loop()
{
uint32_t timePrev = 0;
uint32_t timeStart = micros();
uint32_t samples = 80000;
timePrev = timeStart;
for (uint32_t iterationCount = 0; iterationCount<samples; iterationCount++){
delayMicroseconds(iterationCount * 2000.0/samples);
uint32_t timeNow = micros();
fillbuffer(iterationCount, timeStart, timeNow, timeNow-timePrev);
timePrev = timeNow;
Serial.print("START\n"); //header
Serial.print(datastring);
Serial.print("\n\n"); //footer
//Serial.send_now();
}
while(1){};
}
#!/usr/bin/env python
import serial # requires pyserial
import sys, os
def collectRawData(port, samples):
collected_data = False
serial_timeouts = 0
f = open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'raw.txt'), 'w')
f.seek(0)
with serial.Serial(port, timeout=0.01) as ser:
i = 0
while i<samples:
i += 1
newline = ser.readline()
if not newline:
serial_timeouts+=1
else:
collected_data = True
serial_timeouts = 0
if collected_data and serial_timeouts>100:
break
f.write(newline)
if (i%1000) == 0:
print i
f.close()
def parseRawData():
message_length = 5 # iteration, ts, deltatime, serialbytes, bytelength
with open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'parsed.csv'), 'w') as out:
with open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'raw.txt'), 'r') as f:
state = 0
buffer = ""
line_number = 0
data_iteration = 0
for line in f:
if line.strip() and (line.strip() == "START"):
if state <= 0: #-1 when recovering from an error
state = 1
else:
#error!
print "****** unexpected start sequence: '", line.strip(), "' @ line ", line_number
data_iteration += 1
# don't put bad data line in our outfile
state = 0 # reset for next S
elif state > 0 and state < message_length:
buffer = buffer + line.strip() + ", "
state += 1
elif state == message_length:
buffer = buffer + line.strip() + "\n"
state += 1
elif state == message_length + 1: #first tailing \n
if line.strip():
print "****** unexpected text: '", line.strip(), "' @ line ", line_number
data_iteration += 1
state = 0 #skip to START seek
else:
state += 1
elif state == message_length + 2: #second tailing \n
if line.strip():
print "****** unexpected text: '", line.strip(), "' @ line ", line_number
data_iteration += 1
state = 0 #skip to START seek
else:
try:
data_iteration = int(buffer.split(',')[0])
out.write(buffer)
buffer = ""
state = 0 # reset for next S
except:
print "****** iteration can't be found: '", line.strip(), "' @ line ", line_number
state = 0 # reset for next S
else:
print "syncing to 'START' @ line", line_number
if state == 0:
buffer = str(data_iteration) + ', ' + ( '-1, '*(message_length-1) ) + '\n'
out.write(buffer)
print "error line: ", buffer
buffer = ""
state = -1 #don't write multiple error lines
line_number +=1
if __name__ == '__main__':
collectRawData('COM7', 500000)
parseRawData()
if (++wait_count > TX_TIMEOUT || transmit_previous_timeout) {
transmit_previous_timeout = 1;
return -1;
}
C:\Program Files (x86)\Arduino\hardware\teensy\avr\cores\teensy3\usb_serial.c -o C:\Users\Robb\AppData\Local\Temp\build8800891962364582893.tmp\usb_serial.c.o
C:\Program Files (x86)\Arduino\hardware\teensy\avr\cores\teensy3\usb_serial.c: In function 'usb_serial_write':
C:\Program Files (x86)\Arduino\hardware\teensy\avr\cores\teensy3\usb_serial.c:184:11: warning: variable 'wait_count' set but not used [-Wunused-but-set-variable]
uint32_t wait_count;
// #define TX_TIMEOUT_MSEC 70
#define TX_TIMEOUT_MSEC 90
static uint8_t transmit_previous_timeout=0;