Re: USB, Serial port -- what is it worth ?
- From: goog49@xxxxxxx
- Date: 15 May 2007 05:45:43 -0700
On May 15, 5:13 am, Marten <mar...@xxxxxxxxxxx> wrote:
I'm still unsure how to look at these ports. Therefore I would like to
ask you all: what can be done with the USB or the new serial port ?
USB port
- Could I add a bluetooth device to be able to communicate with a
modem ?
- Could I add an USB memory stick ?
- Do I have programmable access to the USB line ?
Serial Port
- Could I add an analog modem to the device ?
- Do I have programmable access to the USB line ?
- A cable seems to be there from a third party company for a high
price ($60) - though it may be ok. But can I add a normal analog modem
to this cable ?
Marten
I can't comment on the USB port except to say, from my limited
knowledge of the protocol, that the calculator _is_ the add-on. You
need a PC at the other end. At least that's the way I see it.
Now, then - the serial port. In theory, you can hack a cable together
with a level shifter and inverter, or do what I did, and buy the cable
from Samson Cables. Doing it yourself isn't a groundbreaking piece of
engineering - I just didn't want to put something together with a
soldering iron and shrink-wrap.
I'm writing programs that talk to a GPS receiver and a Kenwood TH-
D7A(G) data radio. You use the classic calculator serial port
commands, BUFLEN, SRECV, XMIT, OPENIO, CLOSEIO, and all the others.
Flag -78 toggles the port between serial and USB. Works fine. Should
work with a telephone modem, if that's what you have in mind.
I tested the Samson Cables cable at the highest speed listed. I've
heard that some units have trouble at _slow_ baud rates. This may
have to do with the self-biasing nature of the chips used, but I can't
say for sure. I've noted no problems from 4800 baud on up.
What I have so far is an add-on to the program described in
http://members.cox.net/above.
I'm going to troll for ideas about other stuff to do with the data
radio...
.
- References:
- USB, Serial port -- what is it worth ?
- From: Marten
- USB, Serial port -- what is it worth ?
- Prev by Date: Development tools, was: Urgent: 50g anti-piracy by 5 June 2007
- Next by Date: Re: Should EMU48/49 backup on startup by default?
- Previous by thread: USB, Serial port -- what is it worth ?
- Index(es):
Relevant Pages
|
