HP 50G serial cable
Eric Rechlin
will have some unusual features that could be useful to hobbyists, while at
the same time having ultra-low power consumption.
My target price is no more than US$20, and it will likely be even cheaper
once the design is finalized. I wouldn't normally be doing this, but the
price of a certain other cable on the market is obscene, and I think I can
provide a better product at a significantly lower price. I don't want this
to sound like an advertisement, but it bothers me to see a cable selling for
half the price of the calculator so I felt the need to develop this.
I hope to have it ready within a couple weeks. If you might be interested,
please email me with your intended use. I will probably want to pick a
couple individuals to help test it.
Regards,
Eric Rechlin
reth
Good on you, Eric!
I'll be using it to upload/download data to/from Leica total stations
so I'd buy a couple with free end or 9 pin m/f connector.
Cheers,
Reth
jeff
I wish you good luck. We discovered many issues when trying to solve
this strange problem hp has handed us. The power line on the port is
always on, it doesn't power down when the calculator is powered down,
so you can't leave the cable plugged in or it drains the batteries in
a very short time. Since the hp50 doesn't provide 1200 baud, you have
to address that issue, if you wish to communicate with any device that
operates at that speed. A task that seems so simple became very
complicated and the price to develope the circuitry to perform the
chores that the hp48 accomplished out of the box doubled from the
first estimate to the final design and then produce in numbers. If
you are able to do that for $20, more power to you. So far R&D has
cost well over $10,000
Jeff
Wes
serial port? The 48gII data sheet says that it comes with a serial
cable to connect to a PC. Perhaps a better question would would be:
What is the difference between the serial cable that comes with the
48gII and the ones for the 50g? According to past posts, the 48gII
cable also has some electronics embedded within it.
-wes
Wes
Colin Croft
>
> I wish you good luck. We discovered many issues when trying to solve
> this strange problem hp has handed us. The power line on the port is
> always on, it doesn't power down when the calculator is powered down,
> so you can't leave the cable plugged in or it drains the batteries in
> a very short time. Since the hp50 doesn't provide 1200 baud, you have
> to address that issue, if you wish to communicate with any device that
> operates at that speed. A task that seems so simple became very
> complicated and the price to develope the circuitry to perform the
> chores that the hp48 accomplished out of the box doubled from the
> first estimate to the final design and then produce in numbers. If
> you are able to do that for $20, more power to you. So far R&D has
> cost well over $10,000
>
> Jeff
>
I purchased one of Samson's cables to try to see if it would allow the
serial port on the 39gs/40gs to be used with the old software (HPGComm)
that was used for the old model 39G calculators released back in 2000.
Part of the reason for this is that I (and others) have encounted some
problems with the stability of the communication via the USB port. It
tends to drop in and out all the time and sometimes takes quite a long
time to establish a connection. I get inquiries via my website quite
often about it. The old 39G, on the other hand, had *extremely* reliable
communication with the PC and the HPGComm program was very easy to use.
It was mainly in the nature of an experiment but what I've found is that
the connection using the mini-serial port and the cable from Samson does
not seem to be reliable. It will seem to start to transmit and then time
out or report "No longer in communication with calculator" or "Bad data"
or "Invalid object". I can't even get it to do a screen capture, which
is about as basic as you can get.
I'm not really up on the hardware/cable side of things - can anyone
suggest if this is worth pursuing? I seem to recall that there were some
comments in a previous thread about some of the Samson cables being
faulty - how can I tell if mine is ok or not? ie whether the problem is
that the 39gs just won't work with the old software or whether it's the
cable?
Jim D.
If you would send an email to Samson and ask that they forward it to me,
I will resolve any issues that I can.
(Just say forward this to Jim D.)
The cable will perform to specifications - or else! :-)
Jim D.