VT132 modem+ Wifi = reboot.

[Andres Plaza]

Hi,

I'm slowly coming back to all my hardware after moving to a new house (more space, so it is great!), and finally found the VT132 standalone to play with. Last time I connected it, I was able to connect to WiFi and to a few BBS, to test.

But now, although I have not changed the WiFi SSID and password, it did not connect. Well, I said, maybe it lost the info, not a biggy: I tried the AT+W=sss,ppp command but, after pressing Enter, the VT132 reboots (after a few seconds it shows "Wait" and then it goes back to whatever was configured, online or local). Even using AT+W+ reboots it. AT+W? shows "WIFI NOT STARTED".

FYI, ATI2 shows v4.0.1-199-gb9e89a254

Any ideas of what could be happening, and how to fix it?

Thanks!

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Andres Plaza R.

[Andres Plaza]

Oh, I should mention:

* Using firmware 1.2.0

* Tried erasing NVR; same problem

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Andres Plaza R.

[Andres Plaza]

This is bad... :-(

Using FTDI, I upgraded the VT132 to 1.4.0. Cleared NVR and, without thinking, I selected the option to connect to WiFi automatically... And now the VT132 is in a constant loop of rebooting, never coming back (it does not even beep, but I can see the lights of the keyboard turning on and off).

Any suggestions or ideas are welcome.

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Andres Plaza R.

[Andres Plaza]

So... I connected my Imsai 8080 replica to the VT132, and I did not see anything.

I'm guessing, at this point, if the ESP32 is busted (correct me if I'm wrong, but the WiFi functionality has nothing to do with the PCB). I'm wondering if my next step should be unsoldering it from the board (what a pain) and test it outside of it.

Opinions?

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Andres Plaza R.

[TheHighNibble]

Hi Andres, sorry for the delay responding - been a busy week wrapping up the school term.

Good idea to upgrade to V1.4.0

I'm sorry that setting Enable wi-fi autoconnect put you in an unrecoverable loop. I'll take a look at the code and try to prevent that from happening on wi-fi failure to connect.

Meanwhile I would not give up on the ESP32 you have just yet.

The first thing to try is a full erase of the ESP32 flash and then reinstall V1.4.0

Something like:

esptool.py --chip esp32 --port /dev/tty.usbserial-A105T1N1 --baud 2000000 erase_flash

changing the "port" path for whatever you used when you upgraded to V1.4.0 over the FTDI

Let me know how you get on.

[Andres Plaza]

[Just realized I didn't answer the list, copying my answer here:]

Hi,

No worries, we are all doing this in our spare time, for fun. :-)

I was reviewing the emails I sent, and I missed one important detail: some time after I enabled the option to connect to the WiFi automatically, and the VT132 went into a reboot loop, the system stopped rebooting and I got a terminal prompt; that's why I thought about test connecting the VT132 to the IMSAI 8080 replica (otherwise, it did not make sense). As I mentioned, I did not see any output in the physical serial (I was able to see the CP/M output in the virtual serial of the IMSAI 8080, and the configuration seems to indicate the serial is being sent to both physical and virtual).

I just tried doing the erase_flash and writing 1.4.0 again, but I get the same symptoms: as soon as I use AT+W+ or AT+W=SOMETHING,SOMETHING , the VT132 reboots.

Any other ideas?

Thanks,

Andres.

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Andres Plaza R.

[TheHighNibble]

When things are working but starting WiFi causes a reboot usually indicates a power problem.

Just as the WiFi starts, the current draw spikes and will cause a brown-out if the power supply is marginal.

For example, I cannot start WiFi if I am powering my VT132 from the FTDI connector/adapter.

How are you powering your VT132? Can you try some other options?

[Andres Plaza]

Aha!!!

I just changed to a 12V 3A and problem solved!!! :-)

I really thought 5V 4A was enough...

Thank you so much!

Andres

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Andres Plaza R.

[TheHighNibble]

>> I really thought 5V 4A was enough...

It absolutely should be. I use a 5V 2A switch mode supply without a problem.

Maybe that supply is failing or has marginal voltage. But also, if you are feeding in 5V you need JP6 in place to bypass the 7805 regulator.

But I'm glad you have it working.