problem interfacing BS2sx to iPAQ Pocket PC w/ RS232 serial
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I'm currently working to design a robot control system using an iPAQ H3640
Pocket PC as the CPU. A BS2sx is used to output PWM and digital control signals
to the robot, as well as read an ADC and control the address on a pair of
multiplexers. The iPAQ's serial port is connected to these multiplexers,
allowing the stamp to switch communication to/from the iPAQ between itself, a
GPS, and a video text overlay device. The problem is this: once the multiplexer
is switched to one of the other devices, communication between the iPAQ and
stamp is lost. We had intended to signal the stamp using the DTR or RTS lines
on the iPAQ's serial port, and then have the stamp switch the multiplexer back
to itself to accept new instructions. However, the DTR and RTS lines on the
serial port don't seem to change state when our software tells them to,
according to the stamp (and a multimeter). I'm wondering if anyone has
attempted this sort of thing before. I imagine someone must have wanted to
output with a single serial port to multiple BS2's... Any information on what
special considerations need to be taken with the handshaking lines on the serial
port of a handheld or perhaps someone can recommend a chip that would escape
certain byte sequences from the serial communication and switch the multiplexer
accordingly? An internet search hasn't turned up anything useful on these
topics. Thanks.
Ryan Meador
Electrical Engineering Student
Cold Regions Research and Engineering Laboratory
email: ryan.meador@e...
phone: (603) 646-4454
Pocket PC as the CPU. A BS2sx is used to output PWM and digital control signals
to the robot, as well as read an ADC and control the address on a pair of
multiplexers. The iPAQ's serial port is connected to these multiplexers,
allowing the stamp to switch communication to/from the iPAQ between itself, a
GPS, and a video text overlay device. The problem is this: once the multiplexer
is switched to one of the other devices, communication between the iPAQ and
stamp is lost. We had intended to signal the stamp using the DTR or RTS lines
on the iPAQ's serial port, and then have the stamp switch the multiplexer back
to itself to accept new instructions. However, the DTR and RTS lines on the
serial port don't seem to change state when our software tells them to,
according to the stamp (and a multimeter). I'm wondering if anyone has
attempted this sort of thing before. I imagine someone must have wanted to
output with a single serial port to multiple BS2's... Any information on what
special considerations need to be taken with the handshaking lines on the serial
port of a handheld or perhaps someone can recommend a chip that would escape
certain byte sequences from the serial communication and switch the multiplexer
accordingly? An internet search hasn't turned up anything useful on these
topics. Thanks.
Ryan Meador
Electrical Engineering Student
Cold Regions Research and Engineering Laboratory
email: ryan.meador@e...
phone: (603) 646-4454