[Gumstix-users] C++ coding on gumstix

[rketcham <Ric...@gm...>]

Hi,=20
I'm having a slight problem with some code I wrote for the gumstix in c++.
Essentially, I want to take in numeric values from a sensor node and conver=
t
those values to a string. On my Ubuntu platform, it works fine. This is the
printout:

Enter the Basestation's com port number to use:
0
open_port: Port /dev/ttyUSB0 was opened successfully.
insert into LDC448 (TimerTick,NodeAddress,ChannelData) values (80,448,8190)
insert into LDC448 (TimerTick,NodeAddress,ChannelData) values (81,448,8190)

The numbers 80 448 and 8190 were correctly converted to strings.=20

However, when I compiled it using the c++ cross-compiler and then used it o=
n
the gumstix (via ssh), it didn't quite work so smoothly.  Here's the
printout:

Enter the Basestation's com port number to use:
0
open_port: Port /dev/ttyUSB0 was opened successfully.
insert into LDCX=EF=BF=BD (TimerTick,NodeAddress,ChannelData) values (X=EF=
=BF=BD,X=EF=BF=BD,X=EF=BF=BD)
insert into LDC=EF=BF=BD=EF=BF=BD! (TimerTick,NodeAddress,ChannelData) valu=
es (=EF=BF=BD=EF=BF=BD!,=EF=BF=BD=EF=BF=BD!,=EF=BF=BD=EF=BF=BD!@)


Here's the gist of the program:

std::string s;

s=3D"insert into LDC"+stringify(ldcPacket.nodeAddress)+"
(TimerTick,NodeAddress,ChannelData) values (" +
stringify(ldcPacket.timerTick) + ","+ stringify(ldcPacket.nodeAddress)+ ","=
+
stringify(ldcPacket.channelData.back())+")";=09

cout<<s<<endl;

where stringify is this function:

//Convert a number to string using a string stream
inline std::string stringify(double x)
{
=09std::ostringstream o;
=09o<<x;
=09return o.str();
}

This is what's included:

#include <iostream>
#include <exception>
#include <limits>
#include <sqlite3.h> //sqlite version 3
#include <string>//Added


Okay. During the process of writing the above, I managed to fix the problem
by doing the following:

std::stringstream s; //SQL string

s<<"insert into LDC"<<ldcPacket.nodeAddress<<"
(TimerTick,NodeAddress,ChannelData) values
("<<ldcPacket.timerTick<<","<<ldcPacket.nodeAddress<<","<<ldcPacket.channel=
Data.back()<<")";=09

cout<<s.str()<<endl;

If any of you know why this worked and not what I had above, please let me
know.

Thanks,
Rich

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