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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hello all,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>In a Nut/OS 3.3.2 program one of the things I’m doing
is reading from serial port 0 using <span class=GramE>fread(</span>). <span
style='mso-spacerun:yes'> </span>Occasionally, <span class=GramE>fread(</span>)
returns < 0.<span style='mso-spacerun:yes'> </span>This puzzles me,
since shouldn’t it block until the specified number of bytes are
available? <span style='mso-spacerun:yes'> </span>I don’t see how an
error condition could form with this embedded hardware.<span
style='mso-spacerun:yes'> </span>I had big problems with this issue using
version 3.3.0 (or maybe .1?), it always failed.<span
style='mso-spacerun:yes'> </span>To fix the problem (mostly) I upgraded
to 3.3.2.<span style='mso-spacerun:yes'> </span>It works a lot of the
time, maybe 85%, but others it returns the error…<span
style='mso-spacerun:yes'> </span>Also note that errno is set to 0, I
assume it’s not implemented fully.<span style='mso-spacerun:yes'>
</span>Here is how I’m opening the serial port and reading data from it:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span>//Open serial
port<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>NutRegisterDevice(</span>&devUart0, 0, 0);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span>cd.rs232 = <span
class=GramE>fopen(</span>"uart0", "r+b");<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>tmp</span> = DATA_UART_SPEED;<span style='mso-tab-count:2'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span>_<span
class=GramE>ioctl(</span>_fileno(cd.rs232), UART_SETSPEED, &tmp);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
style='mso-spacerun:yes'> </span><span class=GramE>tmp</span> = 1;<span
style='mso-tab-count:2'> </span>//Odd
parity<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
style='mso-spacerun:yes'> </span>_<span class=GramE>ioctl(</span>_fileno(cd.rs232),
UART_SETPARITY, &tmp);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>NutSleep(</span>500);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>///////////////////////////////////////////////////////<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><span class=GramE><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>size_t</span></font></span><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
readFull(void *ptr, size_t size, FILE *fp)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>{<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>size_t</span> retVal;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>size_t</span> numRead = 0;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>unsigned</span> char *cptr;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>cptr</span> = (unsigned char *) ptr;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:1'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>while(</span>numRead < size)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span>{<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>retVal</span> = fread(&cptr[numRead], 1, size - numRead, fp);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:2'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>if(</span>retVal < 0)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span
style='mso-spacerun:yes'> </span><span
class=GramE>return(</span>retVal);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:3'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>numRead</span> += retVal;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:1'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>return(</span>numRead);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><span class=GramE><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>char</span></font></span><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
readDih(FILE *fp, struct dihType *dihPtr)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>{<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>size_t</span> retVal;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:1'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>retVal</span> = readFull(dihPtr, DIH_SIZE, fp);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:5'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>if(</span>retVal <= 0)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>return(</span>CONNECTION_ERROR);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:2'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>if(</span>dihPtr->magic != MAGIC_NUMBER)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>return(</span>XFER_ERROR);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-tab-count:2'> </span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><span style='mso-spacerun:yes'> </span><span
class=GramE>return(</span>OK);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The <span class=GramE>readFull(</span>) function fails ‘sometimes’
when called to read a packet of data from the serial port which is always 60
bytes.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>If anyone can help it would be greatly appreciated.<span
style='mso-spacerun:yes'> </span>This controller is for an in house
machine that needs to be online ASAP. <span
style='mso-spacerun:yes'> </span>This is the reason it is not online
yet!<span style='mso-spacerun:yes'> </span>Please help!<span
style='mso-spacerun:yes'> </span></span></font><font size=2
face=Wingdings><span style='font-size:10.0pt;font-family:Wingdings;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial;mso-char-type:
symbol;mso-symbol-font-family:Wingdings'><span style='mso-char-type:symbol;
mso-symbol-font-family:Wingdings'>J</span></span></font><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoAutoSig><font size=3 face="Times New Roman"><span style='font-size:
12.0pt;mso-no-proof:yes'>Kyle Rhodes<o:p></o:p></span></font></p>
<p class=MsoAutoSig><font size=3 face="Times New Roman"><span style='font-size:
12.0pt;mso-no-proof:yes'>Hardware / Software Engineer<o:p></o:p></span></font></p>
<p class=MsoAutoSig><font size=3 face="Times New Roman"><span style='font-size:
12.0pt;mso-no-proof:yes'>gh, LLC<o:p></o:p></span></font></p>
<p class=MsoAutoSig><st1:Street><st1:address><font size=3 face="Times New Roman"><span
style='font-size:12.0pt;mso-no-proof:yes'>3000 Kent Ave</span></font></st1:address></st1:Street><span
style='mso-no-proof:yes'><o:p></o:p></span></p>
<p class=MsoAutoSig><st1:place><st1:City><font size=3 face="Times New Roman"><span
style='font-size:12.0pt;mso-no-proof:yes'>Lafayette</span></font></st1:City><span
style='mso-no-proof:yes'>, </span><st1:State><span style='mso-no-proof:yes'>IN</span></st1:State><span
style='mso-no-proof:yes'> </span><st1:PostalCode><span style='mso-no-proof:
yes'>47906</span></st1:PostalCode></st1:place><span style='mso-no-proof:yes'><o:p></o:p></span></p>
<p class=MsoAutoSig><font size=3 face="Times New Roman"><span style='font-size:
12.0pt;mso-no-proof:yes'>(765) 775-3776<span style='mso-spacerun:yes'>
</span>ext 205<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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