Serial port questions

[SimonLothar]

What kind of DB9-connector does your WiSnap have. Male or female?
Do you use any gender changer?

[happy Profile]

Male. The 3pin-serial I bought (the one that used to be called FA-122) has a female plug. So nothing in between: calculator, cable, WiSnap. To configure WiSnap: laptop, USB-Serial adapter, a gender changer (female on both ends), WiSnap. (That worked..)

[SimonLothar]

Male. The 3pin-serial I bought (the one that used to be called FA-122) has a female plug. So nothing in between: calculator, cable, WiSnap. To configure WiSnap: laptop, USB-Serial adapter, a gender changer (female on both ends), WiSnap. (That worked..)

That's a bit peculiar. Do you know, if your gender changer is a straight through or a crossover type?

I understood, the WiSnap has some dip switches. How are these set?

[happy Profile]

That's a bit peculiar. Do you know, if your gender changer is a straight through or a crossover type?

No clue. Those ones were lying around in the house, atleast 10 years old, don't even remember why I bought them in the first place! How do I find out?

I understood, the WiSnap has some dip switches. How are these set?

I haven't touched them, so all are "on" (default). Anyway, from the manual, only 1 seems to be used (the 1st one). On/Off determines whether WiSnap should startup with an ad-hoc LAN or not.

There are also these jumper settings. "The WiSnap AAA Dongle serial interface can be configured to enable flow control and null modem signalling. The jumper block is accessed by removing the battery cover from the WiSnap AAA Dongle." Again, haven't touched them. It is set to "Male DB9 (Default Config)". Other ways to set the jumpers are "Male DB9 - Null Modem", "Drive DTR on pin 4 of the male DB9", "Drive DSR on pin 6 of the male DB9" or "Drive DCD on pin 1 of the male DB9".

I haven't gotten as far as to setting up WiSnap to automatically call URLs etc. Thought it was pointless doing it unless I see that it is accepting serial data from the calculator. Did however set it up to connect to my home WLAN and get itself an IP etc.

[SimonLothar]

No clue. Those ones were lying around in the house, atleast 10 years old, don't even remember why I bought them in the first place! How do I find out?

If you have a continuity tester, check if pin 2 of either side of the gender changer are connected. Then you have a straight through type. If pin 2 and the other side's pin 3 are connected, you have a cross over type.

You are sure that the jumper setting at present is 1-2 and 3-4 (Male DB9 default) and not 2-4 and 1-3 (Male DB9 Null modem) according to page 9 of the manual?

If the gender changer is a straight through type and the laptop works with the WiSnap, then it is not possible, that the WiSnap works without some crossover device with the calculator. In this case I would try the WiSnap "Null modem" jumper setting. But do not set the DTR, DSR or DCD jumper settings!
If the gender changer is a crossover type, I will upload two programs (tomorrow), one receiver for your laptop and one sender for your calculator, to do further diagnostics.

[happy Profile]

If you have a continuity tester, check if pin 2 of either side of the gender changer are connected. Then you have a straight through type. If pin 2 and the other side's pin 3 are connected, you have a cross over type.

I don't know what a continuity tester is, but in the morning will ask around if anybody I know knows and try and figure this out.

You are sure that the jumper setting at present is 1-2 and 3-4 (Male DB9 default) and not 2-4 and 1-3 (Male DB9 Null modem) according to page 9 of the manual?

Yes, it is like in the diagram for Male DB9 default.

If the gender changer is a straight through type and the laptop works with the WiSnap, then it is not possible, that the WiSnap works without some crossover device with the calculator. In this case I would try the WiSnap "Null modem" jumper setting. But do not set the DTR, DSR or DCD jumper settings!
If the gender changer is a crossover type, I will upload two programs (tomorrow), one receiver for your laptop and one sender for your calculator, to do further diagnostics.

Thanks, I really appreciate this!

(Also, check this video out, especially from 1:14 - http://www.youtube.com/watch?v=jw-JqGEpf6E. I was hoping my calculator would work just as easy! )

[happy Profile]

If you have a continuity tester, check if pin 2 of either side of the gender changer are connected.

Not done this yet, but:

If it is straight through, I will need to change the jumper settings depending on whether I connect WiSnap to laptop or to calculator, right? I'd rather not, since I would need to connect to either frequently (laptop, to configure WiSnap and calculator, to test my addin). So can I use something like http://www.pccables.com/01323.html while connecting to calculator and leave jumper settings always as 'Male DB9 default'?

And if it is cross over, we don't know what to do yet?

FWIW the gender change cable I use looks exactly like this: http://en.wikipedia.org/wiki/File:Null_ ... able_1.jpg (taken from http://en.wikipedia.org/wiki/Null_modem which seems to hint that majority of null modem cables are of the cross-over type)

[SimonLothar]

If it is straight through, I will need to change the jumper settings depending on whether I connect WiSnap to laptop or to calculator, right? I'd rather not, since I would need to connect to either frequently (laptop, to configure WiSnap and calculator, to test my addin). So can I use something like http://www.pccables.com/01323.html while connecting to calculator and leave jumper settings always as 'Male DB9 default'?

Yes, that would be sensible (but I think in this case useless; see below).

And if it is cross over, we don't know what to do yet?

Yes, further investigations would be necessary.

FWIW the gender change cable I use looks exactly like this: http://en.wikipedia.org/wiki/File:Null_ ... able_1.jpg (taken from http://en.wikipedia.org/wiki/Null_modem which seems to hint that majority of null modem cables are of the cross-over type)

A Null-Modem is a cross-over device by definition. Usually gender changers (both connectors assembled in the same case; no cable) are straight through, unless they are labeled "Null-modem". Though, a cable with female connectors on either side usually is a Null-modem, t. i. cross-over.

Obviously the hardware is not the problem. I will prepare a test package.

Did you ever try to send "$$$" from the calculator? Does the WiSnap show any LED-activity, if it enters the setup mode?

[happy Profile]

A Null-Modem is a cross-over device by definition. Usually gender changers (both connectors assembled in the same case; no cable) are straight through, unless they are labeled "Null-modem". Though, a cable with female connectors on either side usually is a Null-modem, t. i. cross-over.

Thanks, so from the looks of it, what I have is a null modem cable and not a gender changer.

Did you ever try to send "$$$" from the calculator? Does the WiSnap show any LED-activity, if it enters the setup mode?

Not yet from calculator, will test in 4-5 hours. Yes, it does show LED activity even in command/setup mode (seen while I was configuring it using Macwise).

[SimonLothar]

Perhaps it is a passive-TTL/RS232-converter problem (personally I think this is it!):

On page 8 of the WiSnap manual they say:
"NOTE: The RS232 interface uses the SIPEX SP3232ECA
chip with capacitor switch to generate the + and – signals
and thus is not driving the full RS232 voltages. Devices
stealing power from the RS232 pins may not have enough
voltage."

Above that, if you do not set either of the WiSnap jumpers, which drive DTR, DSR or DCD, your cable won't get power at all. The communication cannot work.

I assume, that your TTL/RS232 converter cable is passive. It tries to steal power from the WiSnap, usually from the pins DTR, DSR or DCD, which are not connected by default.
It is like with the cables described here:
viewtopic.php?f=20&t=1473&hilit=serial+3+pin
There you can see, that the MAX232 pin 16 (its power supply input) is connected with DTR, DCD and/or DSR to the external RS232 device to steal power.

Does your TTL/RS232 converter have means to connect its own external power supply?
Does the manual of your TTL/RS232 converter say, which line of the external RS232-device is used to steal power?

If not:
The WiSnap manual is not clear at this point and I don't want to talk you into some risk. Try to contact the WiSnap manufacturer and ask, if it could be a problem to set one of the jumpers to drive DTR, DSR or DCD. Perhaps it is sufficient to drive one of the WiSnap pins DTR, DSR or DCD.

BTW: I use active TTL/RS232-converters. That's why I got the idea this late. Sorry, I should have thought of it earlier.