Prop Plug Alternative?

electromanj

Hello. Some weekends are better then others. Last night I decided to revive my onboard computer project (http://www.savagecircuits.com/forums/showthread.php?1284-Onboard-Computer/page2&highlight=onboard+computer) as the season is getting ready to start. I had the power connections to the switch dangerously close to where the Prop Plug plugs into the board. After many many many revisions to the project I had worn holes through the heatshrink on the power connectors that made contact with certain parts on the Prop Plug that evidently are not 12 volt tolerant, and put a nice bubble on the FTDI chip. Not a big deal at the time. I decided to move the power switch out of the way, and use my remaining Prop Plug (broken connector replaced with a 4 pin header solder at a 90 degree angle.) This was going to be nice because with the right angle I could drill another hole in the enclosure and plug straight in without having to remove the cover! Very ingeniously I plugged the Prop Plug into the board so I could Very wisely line up the pilot hole. That was a fantastic idea and I have to say that the hole was dead on. That is proved by the brand new hole in the usb connector of my remaining Prop Plug! I ordered a new Prop Plug this morning from another vendor (P is out of stock at the moment) but now I'm in a pickle. I have a few of the serial to usb adapters, and means to make cables. Is there any hope of using these as an alternative until I recieve my new Prop Plug?

Thanks,
traVis.

doggiedoc

I like your 90 degree connector on the one fix! But I don't think you can use the USB-Serial connector because of level shifting. Here's the schematic for the PropPlug....



I'm still looking for the USB-serial schematic.... maybe it's in the BS manual.

Doc

electromanj

I guess if I get really desperate I can pull the eeprom and put it into the PPDB right?

doggiedoc

Do you have a spare surface mount USB connector? You could use a heat gun carefully on one of you USB-SER Adaptors and solder a good connector onto you 90 degree prop-plug. What do you think?

LoopyByteloose

I've never owned a PropPlug. At first, I built a transistor RS232 interface that i used and they work fine if you have a good USB to RS232 adapter or just direct RS232.

http://www.parallax.com/tabid/254/Default.aspx

Parallax also has a USB to SER adapter that I use, but it has a different alignment of pins. Verify that any USB to RS232 is safe for 3.3v and not including an inversion of the logics 1s and 0s.

And my Arduino USB programmer might even work as it provide 3.3v logic serial as an optional feature, but I've yet to try.

electromanj

Thanks for the replies. Removed the USB connectors from the both Prop Plugs tonight using a combination of solder braid and the heat gun. Got a little skittish about getting the good board too hot and shifting a componant and ended up lifting a trace under the connector of the good board. oops! I tried to lay it back in place, and solder on the good connector but to no avail. I think I'll stop now before I do more damage. Regardless I had fun, and the new Prop Plug will be here on Friday.

P.S. I've got to get some of those glasses Doc!

traVis.

Duane Degn

I don't suppose you have an USB version of a Propeller Protoboard?

If so, and you don't mind hacking into it, you could liberate the USB portion to turn into a Prop Plug.

After killing a couple of Prop Plugs myself, I figured it was cheaper to buy a USB Protoboard than it was to buy a regular Protoboard plus a Prop Plug.

Here's the set of headers I added to allow the remaining board accept a Prop Plug.

I scraped off the solder resist on the bottom traces to make the connection to the header pins.

Here's the DIY Prop Plug used with the "donor" board.

And here it is with a normal Protoboard.



Of course this requires an USB Propeller Protoboard in order to make this hack.

I've made two of these DIY Prop Plugs and they have both lasted longer than the two "official" Prop Plugs I orginally used (before burning them out).

Dr_Acula

If I were in this situation I wouldn't be able to wait till Friday!

Looking at the photos on post #1, the middle one looks a perfect replacement (and indeed looks the same as what I use as like Loopy, I've never owned a prop plug). Zooming in, it looks like the right chip (FTDI)

So - if you have three transistors you can use the circuit Loopy posted in #5. Or there is another circuit on the parallax site that uses one transistor (either NPN or PNP) and either a max232 or a max3232. So if you have any of these bits lying around then it could save waiting.

The plug in the picture on the left might be usable too - what is the chip on that one?

Martin_H

I've never used a Prop Plug because I already had an FTDI programmer I use for Arduino programming which supports 3.3 or 5 volts. So I bought Brian Riley's Multi-BUB adapter. It basically switches the six pin FTDI to the Propeller's 4 pin and it's worked great for me.