Seeking Local Help with WP34s

[lcwright1964]

I haven't touched my three units in ages and foolishly tried to update flash them recently. I now have three bricks.

I am keen to connect with someone in my region or even better locally to help me diagnose this in person if possible. If the units flash with someone else's hardware I can pinpoint the problem to my gear, though all seemed well as year or so ago.

I do my flashing old school with the Gene Wright serial cable, the FTDI adapter recommended from Eric Rechlin, and MySamba in a Win XP Fusion virtual machine under Mac Yosemite. Used to work fine, but OS X and Fusion have seen updates since so heaven knows what has changed.

If I can't get these to flash I just might have to send them to someone like Eric to install the USB board. I am.really concerned my cable and adapter are bad and I have fried my units.

It is stupid that I tried to flash the third one after the second failed. But I just had to check.

I am in Toronto. If any WP34S fans are around here who might help if would be delighted. Otherwise, if anyone could point me toward someone who could test the units and solder the USB board for a price I would be elated.

Many thanks.

Les

[Paul Dale]

You are about half way around the world from here, so I can't easily help witht he flashing. I've bricked my 34S's a couple of times and repeated erasure and reprogramming has always bought them back to life.


- Pauli

[TASP]

I would not let such an excellent reason to attend the annual conference slip away . . .

[mfleming]

Hi Les,

Having repeatedly (and reliably) bricked my own WP34's I can attest to Pauli's observation about recovery. I've sometimes had to repeat the process nearly a dozen times before it will take. A couple of suggestions; power the calculator from the FTDI 3.3V rail rather than batteries, and remove and reapply power after every few failures.

I once flashed an HTML web page instead of the .bin file I thought I had downloaded, but I was eventually able to recover!

Good luck with nearby help,
~Mark

[lcwright1964]

Thanks all. I will put these away for a bit and come back to them in time when I am less frustrated. I have plenty of other calculator stuff to amuse me.

I have no idea what an FTDI rail is.

Les

[BarryMead]

(03-28-2016 07:28 PM)lcwright1964 Wrote:  I have no idea what an FTDI rail is.

Les:
FTDI is a company (Future Technology Devices International) who make many of the USB to serial cables and the chips that power them. Some of these cables (the ones recommended to flash the WP34s) have a built in voltage regulator that converts the 5 Volt native USB power down to 3.3 Volts. The 3.3V cables that include this regulator, have enough current (10 milliamps) to power the calculator in addition to converting the USB interface into a serial interface with 3.3V logic levels. This regulated 10mA 3.3V power coming out of the FDTI cable is what mfleming was referring to when he said to "power the calculator from the FTDI 3.3V rail". He means remove the calculator's batteries and use the +3.3V power coming out of the FTDI cable to power the calculator instead of the batteries.

I hope this helps, Barry

[mfleming]

Boy, my face is red! Sorry for the unnecessary jargon. Barry is right, I did intend to suggest powering the calculator from the same source as the serial interface signals. Doing so would insure you did not inadvertently exceed the voltage rating on the processor pins due to low battery voltage (documented in an earlier thread somewhere). I use a small USB to serial breakout board that provides the 3.3V power in my own programming setup.

As an interesting sidenote, I've most always seen voltage supplies referred to as "rails" as in my "3.3V rail" reference. Or when referring to an amplifier whose output can swing all the way from the positive to the negative supply levels as having "rail to rail" output. I'm not really sure of the origin of the term rail (could it be an Americanism?), but I would not be surprised if it dates back to early electrical wiring practices, such as with relay ladder logic. I'd love to see someone chime in with a little history of electrical/electronic terminology

~Mark

[lcwright1964]

Success! I have my ANCIENT Compaq Presario at the office, so I took one unit and my paraphrenalia in today.

Flashed with the new firmware the first time...

Thanks to everyone for your input. Looks like old school was the way to go here. I am so relieved my cable and adapter and calculator are fine, and that something seem to have gotten broken on my my Mac/Fusion/XP set up with various upgrades.

And to think I was going to recycle this old Presario paperweight. But it is good for this one thing

Les

[BarryMead]

(03-29-2016 02:30 PM)lcwright1964 Wrote:  Success! I have my ANCIENT Compaq Presario at the office, so I took one unit and my paraphrenalia in today.

Flashed with the new firmware the first time...

Flashing the WP34s requires VERY PRECISE timing as the data is transferred at 115200 bits per second. Any deviation from a simple standard serial port can throw off the timing including emulation hardware simulation, and other such modern creations. While these things are ALMOST the same as the original thing that they simulate or emulate, there can be tiny differences especially to timing.

You may find that you are able to load/save programs to/from your WP34s with your modern emulation/simulation computer even though flashing does not work, because the Computer to Calculator communication used to load/save programs and data take place at a less critical slower 9600 bits per second and are therefore more forgiving of tiny timing issues.

Great News on reviving your WP34s calculators!

[lcwright1964]

And thank you. I lugged the old notebook home and the other units flashed fine. I have experimented a little with communicating to and from the emulator, and that works both ways too.

Les