Introducing (and interest check) AirTalk: Wireless plug-and-play LocalTalk dongles

[Phipli]

Hi all,
has anyone used the device on a mac plus? If yes, how do you power it? Can we steal some power from e.g. floppy drive connector?
@cheesestraws do you believe it would be ok to solder a wire on the usb +5v terminal and feed it to the floppy drive connector? Would it be already grounded or would in need an additional wire for ground?

Many thanks,

Andrew

Cheesey included a USB Micro port to power it using a USB charger, it doesn't specifically need ADB, that was just for convenience.

 

[cheesestraws]

@cheesestraws do you believe it would be ok to solder a wire on the usb +5v terminal and feed it to the floppy drive connector? Would it be already grounded or would in need an additional wire for ground?

The easiest option would be to power it with USB. It's safe to have the USB and the serial plugged in at the same time: that's what it's for . If you want to power it from the machine, you should be fine to get 5V from the floppy port I think. (I can't remember how much power is actually available from that port but if it can run a floppy drive with a motor in it ought to be fine for this).

Ground—I would give it its own ground pin, mostly because if the box is wired up to a computer through a localtalk box, that box is an isolation transformer. If you're modifying the device to have an extra 5V input, you might as well add the extra GND at the same time and save yourself trouble later if you want to pop it on the far side of a localtalk box.

I'd actually suggest adding the wires to one of the ADB ports rather than the USB port: they're functionally identical, and the soldering job will be much easier because the connections are rather larger.

 

[piernov]

Hi, just for fun I made CopperTalk (blue PCB), "AirTalk on Ethernet". Sadly firmware is in a pretty bad shape, file transfers are extremely slow, so it's not ready to use yet, maybe one day I'll be able to figure out what the problem is, or if ever someone wants to look at it… firmware is mostly the AirTalk firmware ported to Zephyr. Hardware is an STM32F107 MCU.
Also made my own spin of the AirTalk board (black PCB) just for fun as well.

 

[cheesestraws]

Hi, just for fun I made CopperTalk (blue PCB), "AirTalk on Ethernet". Sadly firmware is in a pretty bad shape, file transfers are extremely slow, so it's not ready to use yet, maybe one day I'll be able to figure out what the problem is, or if ever someone wants to look at it… firmware is mostly the AirTalk firmware ported to Zephyr. Hardware is an STM32F107 MCU.

Oh, this is great stuff. Is your AirTalk PCB working reliably / did you have enough information to do it relatively straightforwardly? Reproducibility is great .

Do you know where the slowness in CopperTalk is creeping in? There was a weird issue I never really tracked down with some older AirTalk firmware where there was obviously a timing issue of some description that made things get wedged in a state where there was a big delay in it responding to LLAP frames. Some fix along the line got rid of it, and I never totally worked it out...

 

[piernov]

The AirTalk board is inspired from the schematics you posted a while ago (not sure about the license of that though). It's mostly the same, I mainly added a CH330N for programming and debugging the ESP32 from USB. I redrew it in Kicad and designed the PCB there as well. It runs your FreeRTOS-based AirTalk firmware. Of course I made a few mistakes but that's how it goes, otherwise it seems like it's working as expected between a PowerBook 170 and Mini vMac.

I started porting the AirTalk firmware to Zephyr using the AirTalk board and IIRC it had the same issue I have now with the CopperTalk board. So it shouldn't be related to the MCU or the Ethernet but more likely a threading/queuing problem I guess. Sadly I don't have a great understanding of the inner workings of the firmware (and the LocalTalk protocol and communication with TashTalk) so I'm not sure where to look for the problem.

I put the firmware here for now: https://github.com/piernov/coppertalk_firmware
CopperTalk firmware is on the master branch, AirTalk Zephyr firmware is on the airtalk branch.
(in fact it's been a while since I worked on that and it's a bit of a mess but eh)

 

[cheesestraws]

The AirTalk board is inspired from the schematics you posted a while ago (not sure about the license of that though).

Yeah I really should do something about clarifying the licensing situation. How about this: the AirTalk hardware is under the CERN-OHL-S-2.0. I haven't uploaded my gerbers and stuff, but that's out of inertia rather than anything else. If anyone wants them please let me know and that'll give me the impetus to do something about it. If that license is incompatible with what anyone wants to do with it, please contact me. I am not a license absolutist

added a CH330N for programming and debugging the ESP32 from USB

Good call. Not adding USB for this to mine was, in retrospect, a mistake. Programming and debugging would have been significantly more ergonomic if I had!

more likely a threading/queuing problem I guess

I'm pretty sure that the issues I was seeing was that, but as I said, they "organically" went away before I found out what they were. Sigh.

Sadly I don't have a great understanding of the inner workings of the firmware (and the LocalTalk protocol and communication with TashTalk)

I'm very happy to answer any questions you have about the AirTalk firmware, and I can tell you my understanding of talking to the TashTalk though I'm not an expert in its innards. @tashtari 's own thread about the TashTalk is here: https://68kmla.org/bb/index.php?threads/tashtalk-single-chip-localtalk-interface.38955/ and might be a good place to ask!

(in fact it's been a while since I worked on that and it's a bit of a mess but eh)

Code is always a bit of a mess. I shall find it interesting having a look at your code. Thankyou!

 

[micheledipaola]

Hi all,
has anyone used the device on a mac plus? If yes, how do you power it? Can we steal some power from e.g. floppy drive connector?
@cheesestraws do you believe it would be ok to solder a wire on the usb +5v terminal and feed it to the floppy drive connector? Would it be already grounded or would in need an additional wire for ground?

Many thanks,

Andrew

I am moving files between my Plus and my SE/30 this moment, using two AirTalk boxes.
What I did is using the second ADB port of the AirTalk connected to the SE/30 to plug another ADB cable towards the AirTalk connected to the Plus, thus providing power there too.

All hail @cheesestraws for these little devices!

 

[jazzius]

I am interested in getting this to use with my Macintosh SE for quickly copying files over from my modern PC! I recently got an internal BlueSCSI for it, but I have no convenient way of moving files to it and ZIP disks seem to be flaky and clunky at absolute best. How can I get one of these? What is the asking price?

FYI: Also, is this a kit? I CAN solder by the way and I actually soldered together my BlueSCSI kit myself to begin with.

 

[daanvdl]

Hi Jazzius,

I am working on a Airtalk kit and manuals, aiming at sub €50 for preprogrammed complete sets.
I will update within a few weeks. I need to do some more testing and finetuning before going live.

Cheers,
Daan

 

[Iesca]

Perhaps I missed it, but how does one setup Mini vMac 37's LocalTalk-to-UDP functionality?

 

[cheesestraws]

Perhaps I missed it, but how does one setup Mini vMac 37's LocalTalk-to-UDP functionality?

You need to compile it with -lt -lto udp (IIRC), then it should Just Work.

 

[Phipli]

You need to compile it with -lt -lto udp (IIRC), then it should Just Work.

Unless you persist in trying on an obscure ARM based linux machine, in which case you just lose hours of your life... or so I hear.