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Wookie

New USB Serial to ComLynx Adapter

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So I was reading about the BLL serial to comlynx cable the other day and thougt that a USB version would be simple and cheap. So I designed one. I haven't actually built one yet, but I'm 99% sure it will function the same as the BLL cable.

 

Usblynx_board.png

Usblynx_schem.png

 

You can get the eagle and gerber files from my blog. I have the parts laying around to prototype this. If it works, I'll see if I can have a batch or two of these boards made so I can share with you guys.

 

--Wookie

 

PS The reason I fell off the earth there for a while was because my wife and I had a new baby last September. He's now closing in on one year and I'm having a little more free time so I plan to get back in the saddle soon.

Edited by Wookie

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FTDI do something ready built with an audio jack :-

 

http://www.ftdichip.com/Products/EvaluationKits/TTL-232R-3V3-AJ.htm

 

That doesn't work with the Lynx for two reasons:

1. It operates at 3.3V on the cable. Comlynx is 5V.

2. It separates the receive (Rx) and transmit (Tx) signals on the audio jack. The Lynx doesn't. The comlynx bus has 5V+ on the tip and both Rx/Tx multiplexed on the ring. My adapter has both Rx and Tx on the ring connector in the jack.

 

--Wookie

Edited by Wookie

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You completely missed my second reason. Comlynx multiplexes the receive and transmit on a single wire. The FTDI adapters separate the receive and transmit onto two different wires. Those FTDI adapters will not work with the Lynx.

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You completely missed my second reason. Comlynx multiplexes the receive and transmit on a single wire. The FTDI adapters separate the receive and transmit onto two different wires. Those FTDI adapters will not work with the Lynx.

 

Yes they will if you connect TX and RX like it shows in your schematic. That could be done in the cable to the audio jack.

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You completely missed my second reason. Comlynx multiplexes the receive and transmit on a single wire. The FTDI adapters separate the receive and transmit onto two different wires. Those FTDI adapters will not work with the Lynx.

 

Yes they will if you connect TX and RX like it shows in your schematic. That could be done in the cable to the audio jack.

 

And then you have to also connect the 5V tip from the Lynx to ground with a capacitor.

 

--Wookie

Edited by Wookie

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I just ordered a batch of 5 boards to be made. I'll post build photos when I get them.

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I just ordered a batch of 5 boards to be made. I'll post build photos when I get them.

 

I have been using a proto-board from the FTDI chip manufacturer. The good thing with this chip is that it works with the Lynx non-standard speeds (62500 and 31250) out-of-the-box. Actually my Mttty.exe application already has built-in support for this in case you use Windows. (It also works using wine with Linux).

 

--

Karri

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Did you have to mod it as I said above? Based on all the info I've been able to find, my schematic should work and the stock boards from FTDI won't work without some modding.

 

Still, I won't know if my board works until I build one and try it out.

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So what will the benefits of such a cable give? It looks very interesting and it's got me excited. It's always good to see new hardware devices.

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This is mostly a cable for programmers. It is a way to debug games in development. Previous adapters use old serial or parallel port connections. My board modernizes the adapter to use USB. My boards should arrive in the next couple of weeks.

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I placed my order with batchpcb.com a couple weeks ago and I'm still waiting for the boards...

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I received my boards yesterday. I made a mistake though. I forgot to add the board outline to the silk layer and ask them to cut the board to that shape. So I have to hand cut a pair of notches on the USB end. The next batch will be correct. Here's a pic:

post-20384-128337136298_thumb.png

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I received my boards yesterday. I made a mistake though. I forgot to add the board outline to the silk layer and ask them to cut the board to that shape. So I have to hand cut a pair of notches on the USB end. The next batch will be correct. Here's a pic:

 

Great stuff, any chance you could make me one?

I hereby welcome myself back in action btw. :D

 

Had a couple of rough months with uni, relationship, etc.

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I got my parts yesterday but haven't had time to solder it up yet. I have a few revisions to the design already so once I have the prototype working, I'll send off for another batch of version 2 boards and then take orders here on the board. I haven't worked out the exact cost of each board + parts but it's about $10 I think. So the version 2 adapters will probably be between $15-$20 shipped.

 

--Wookie

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So I took some time to solder up the prototype adapter this morning. When I plug it into my linux box, the LED's blink and the device is detected as a USB serial adapter. I now need to figure out how to test it. I need to write an example ROM that talks on the comlynx.

 

--Wookie

post-20384-128535566137_thumb.jpg

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So I took some time to solder up the prototype adapter this morning. When I plug it into my linux box, the LED's blink and the device is detected as a USB serial adapter. I now need to figure out how to test it. I need to write an example ROM that talks on the comlynx.

 

Much fatser:

Use a BLL loader cart like SIMIS, Alpine GAmes, Champ Rally, Lyxn Reloaded etc and send one of the prototype games

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Does anybody know where I can buy one of those carts? I almost bought Alpine Gamess from Carl at CGE this year. Now I wish I had.

 

--Wookie

Edited by Wookie

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