Communication Issue
CharlieII
Posts: 70
Well, I have always run the Propeller from my breadboard and have never had any issue using the "dip plus" kits, numerous different times. It uses the "prop plug" to do the USB to Serial work.
Well, I tried to move past the breadboard and get an actual PCB worked up so I could take my projects off the desktop and into the real world, but I have a problem with the propeller tool not recognizing the existence of the propeller chip now.
My question is this...
What are the bare essentials needed for the propeller tool software to flash the propeller ram in terms of connections and such?
As it stands, I have just tested the PCB, and the chip has power, RX TX RES and Gnd connections appear as they should be in terms of the wire pinouts vs the little prop plug connections. I took an LED and tested the prop plug GND vs VDD and it lit up, so I assume the GND is good. I also removed and reversed the RX and TX wires at the PCB header to make sure that wasn't the problem. No change.
I connected the wires to the prop plug by removing the little plastic connector and soldering the wires directly to the little tabs. Is it likely that I damaged the prop plug when I did that?
I plan to setup another 40pin propeller on a section of breadboard and try to flash it with the same prop plug to check, but right now I'm tired, and was curious if you all might have some general guidelines or usual suspects when it comes to this sort of thing before I went to bed.
Maybe when I check back in the morning things will look a bit better.
Thanks.
Well, I tried to move past the breadboard and get an actual PCB worked up so I could take my projects off the desktop and into the real world, but I have a problem with the propeller tool not recognizing the existence of the propeller chip now.
My question is this...
What are the bare essentials needed for the propeller tool software to flash the propeller ram in terms of connections and such?
As it stands, I have just tested the PCB, and the chip has power, RX TX RES and Gnd connections appear as they should be in terms of the wire pinouts vs the little prop plug connections. I took an LED and tested the prop plug GND vs VDD and it lit up, so I assume the GND is good. I also removed and reversed the RX and TX wires at the PCB header to make sure that wasn't the problem. No change.
I connected the wires to the prop plug by removing the little plastic connector and soldering the wires directly to the little tabs. Is it likely that I damaged the prop plug when I did that?
I plan to setup another 40pin propeller on a section of breadboard and try to flash it with the same prop plug to check, but right now I'm tired, and was curious if you all might have some general guidelines or usual suspects when it comes to this sort of thing before I went to bed.
Maybe when I check back in the morning things will look a bit better.
Thanks.
Comments
I cut the Prop Plug out of the harness to the PCB and put it on the breadboard where I had setup another prop chip for the sole purpose of testing this. With a seperate Prop Plug it flashed fine. When I stuck the one in there that I had soldered to it did the same thing, no propeller chip found on any port...
Looks like I trashed the Prop Plug when I soldered the wires to it.
So what is a good way to get the thing connected to an actual wire without soldering to the leads leaving it?
Thanks.
www.leonheller.com/Propeller/Propeller_schematic.pdf
I don't understand why you had to solder wires to the Prop Plug. Why didn't you simply put a header on your PCB?
Leon
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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle
Post Edited (Leon) : 4/21/2009 3:20:01 AM GMT
This is the header I used.
www.laddinc.com/shared/pdf/DTM13-12P--12P--R008RevD.pdf
And while that definitely gets the RX,TX, RES and GND wires out of the enclosure, near as I can tell it still leaves me with a handful of wire in one hand, and a USB port on a PC in the other. Only way I could see to reconcile that problem was to connect the two in some way. The Prop Plug seemed the most logical choice.
But I messed up the Prop Plug in the process, so what should I have done? How do you get from wires leaving an enclosure to your USB port cleanly?
lol.
So what if hardly anyone has a serial port on their computers anymore.... not my problem, cause I do.
Looking at the "Alternate Serial Port Connection" in the manual, I can't help but wonder if you can't just skip the transistors between the Prop Tx pin and the pc serial Rx and between the pc Serial Tx and the prop Rx pin.
What's the point of the transistor there? It shows 3.3v on both sides, so what's the point of it?
Thanks.
Post Edited (CharlieII) : 4/21/2009 12:19:18 PM GMT
While making do with what you have when prototyping is sometimes necessary I find it saves time and money in the long run to do a neat professional job once you move beyond the prototype stage.
How am I supposed to connect the 4 wires leaving my header to the Prop Plug in a permanent way, without risking damaging it again by soldering directly to the 4 tabs on it?
I don't understand why putting a header on the PCB keeps coming up. I did. It was a 24pin header, and the 4 com wires were included. That does nothing to solve the problem of connecting those wires to a PC though. The prop plug seemed the obvious choice, but how to get from wire, to prop plug is the question I suppose. The need for transistors and making my own "Prop Plug" little PCB to house the serial stuff makes it less appealing.
The project enclosure I am using is water tight, and it works in conjunction with the 24pin header I linked. Therefore, simply adding another 4 pin header isn't an option.
If you are really fussy there are four pin connectors with a plastic shell that fits the prop plug snugly. Just solder the wires to the back of it.
I guess I just don't see something that "plugs in" as being permanent. I was looking to permanently attach the prop plug to the harness so that when you wanted to program the unit all you needed was a standard USB cord from any computer in the world. I guess if it "clicked" in when you stuck it on there it would probably be fine. But this harness is going to live on the chassis of a vehicle. It needs to be robust, and not fall apart.
Can you point me toward the four pin connector for the prop plug? I"ll take a look at that. Maybe I can glue it together.
Thanks.
After reading your last post I am not sure if you want the computer connected permanently, or are looking for a connector that makes a reliable connection for connecting the computer occasionally for programming/data transfer. If it is an occasional connection and you want to use a standard USB cable you could make a small board to go on the harness with the FT232 circuit and USB connector on it as shown in the attachment.
I then have a USB port on a computer that can communicate with my Propeller chip. The most obvious method of facilitating this connection is via the Prop Plug.
However...
Every joe-blow on planet earth does not own a Prop Plug. But if they have a USB port, and expect to use it, they will have a USB cable. As I will.
So...
What would be nice, is if the Prop Plug were permanently attached to the harness (4 wires consisting of Rx, Tx, Res, and Gnd). That way it was just always sitting there, awaiting you to plug a USB cord into it and program to your heart's content.
Problem...
I have a Prop Plug (usb to serial interface) that wants to recieve a dinky little 4 pin header that merely slides in place and can just as easily come back apart, and on the other hand, I have 4, 20Ga wires that need to connect with that thing.
I think I may just buy a heatsink, and solder it again with the heatsink clipped on the Prop Plug side each time and see if that doesn't cure the issue.
Think of it like this. When you go to download pictures off of most cameras, you will likely find a mini usb jack sitting there. You simply plug in a USB cord, and away you go. What you don't find is a 4 pin header hanging out the side of the camera.
I want the same thing.
I agree. And I could take a picture of precisely that laying on my desk, as that is exactly what I did and I now have a worthless desk ornament.
Do you think it was just a freak deal that the Prop Plug stopped working after I soldered the wires to it? I am tempted to try it again, although burning those things up isn't my goal.
Thanks.
How long a cable do you have between the prop board and the prop plug on the harness. It may be that the signal is too low, distorted, or noisy by the time it gets to the prop.
A little experimenting may be in order. First make sure the signals are going to the right pins on the prop.
The second thing to try would be programming a prop with a cable equivalent to what would be in the harness between the prop and the prop plug to see if that works.
If that works the next thing would be to try programming the prop while connected to the harness in the vehicle with only the prop powered (if possible).
If this works then try programming the prop with the vehicle running.
Yeah, I verified those things a few days ago the night it wouldn't program my board.
First thing I did was take a spare Prop Plug and just use jumper wires to connect it to my harness. It programmed as usual on the first try. I also took the soldered one and pinned it to a breadboard and it would not program another propeller chip I had sitting on the breadboard. I then came right in after that with the good Prop Plug and programmed that one just fine on the first try as well.
It's definitely toast.
I have no idea...
I have taken zero measures to protect against static discharge because I don't know what to do, other than just keep moving forward and hope it doesn't damage anything. My soldering iron is a Weller WES51.
I don't know anything about grounding it.
The only thing I am planning at the moment is to buy a heatsink that I can clip onto leads on the component side that can help pull the heat out of the lead before it reaches the component itself.
Any other soldering tips are welcome and appreciated.
Thanks.
I have done the following for my workbench:
Installed a heavy duty power strip with surge protection'
Mounted 4 banana jacks on the power strip and connected them to ground through a 1 meg resistor.
Made a piece of pink antistatic foam (16x24 inches) into an anti static mat (fender washer on both sides with a bolt and nut for wire) and screw it to one of the banana plugs.
Made a wrist strap from a dead watch with the metal flexible strap. I removed the innards and glass, had a small stud brazed to the back, and viola, a very comfortable wrist strap. The wire from the strap to the banana plug is a very flexible wire with silicone rubber insulation from an instrument that was scrapped.
The only items I had to buy was the banana jacks and plugs and the fender washers. Everything else I either had in my junk box or was already using.