Problem of connection of my Propeller Education Kit with my PC!

Marc91

Hello,

I am a French student who just bought the Propeller Education Kit (40-PIN DIP version).

I’ve followed the instructions of the book (PE Kit Labs: Fundamentals). On part three (Setup and testing Lab), I’ve made the circuit step by step as written. I’ve made all the verifications written: they are ok. I’ve downloaded Propeller Tool version 1.2.7 (R2).

But when I try to connect my circuit with my computer using the USB cable, that doesn’t operate as expected. All the verifications from page 19 to page 32 are ok except this one, on page 32 : “Check the AC voltage across the red and black power connectors”. Instead of 50mV, I have 11mV. I don’t know whether it’s important or not… They‘ve spoken of 300mV values, while I have a lower value than expected.

My error happens in the paragraph “Test Communication” page 32, so I went to Troubleshooting entries 6 and 1. I’ve check everything from the sixth entry: it’s ok. Then, I’ve done all the instructions from the first entry. My error message says “No Propeller chip found on serial port”. I’ve tried on two different computers (one is in Windows XP, the other in Windows 7), with several USB ports, and I have the same problem every time. They both recognize the new USB device and have said “Your new hardware is installed and ready to use”. But when I press F7, I have the error message.

Here are pieces of information that I’ve noticed.

- - My computers recognize my USB device, because I can see it in the Device Manager.
- - In the Serial port Search List, in Propeller Tool, I have a port named “USB Serial Port” which is included in the search.
- - When I plug my USB link, I have a red and a blue lights shining for a very short while.
- - All the tensions have good values (except AC values).
- - I have re-installed Propeller Tool and shut down my computers several times.
- - I have re-installed (manually) the drivers.
- - My green LED is glowing faintly when my USB link in plugged (only USB).
- - My green LED is glowing brightly when I add the battery.
- - My error message happens when I have the battery and the USB link plugged.

After having done several times all this section, I’m now at “f. Contact Parallax Tech Support”. Hence, here is a list of questions I have.

What can I do? Do you have any idea where does the problem come from? Does that mean that my Propeller microprocessor doesn’t operate? How can I fix it?

Thanks to help me. If you have any questions, I would be pleased to answer it.

Marc Belardi

Mike Green

You have already taken care of most of the possible reasons for the error message. The Propeller Tool has to carry on a conversation with the Propeller chip with some tight time constraints, so there must be power and there must be a good serial connection between the PC and the Propeller. You are using the PropPlug with the proper drivers, so that should work. The crystal and EEPROM don't have to work at this point. You have checked the power supply voltages and they seem to be correct.

Check your wiring yet again. Some kind of wiring error is a common source of problems. Try a fresh battery.

You will probably have to contact Tech Support directly at <support@parallax.com>. When you have already dealt with the common causes, it often takes direct personal contact to sort out the trouble.

Marc91

Thanks for your answer.

Mike Green wrote: »

Check your wiring yet again. Some kind of wiring error is a common source of problems. Try a fresh battery.

My battery is new, and it voltage is correct.
I've checked my wiring again, and it's exactly the same than in the book.
I’ve also noticed that when I press F7 in the Propeller Tool, (Identify Hardware), the red and blue lights on the Propeller Plug also flicker briefly. And then, this error message happens. Any idea?


I’ve sent an email to Propeller’s support. Does anyone know if they answer quickly?

Mike Green

Pressing F7 in the Propeller Tool starts the same conversation used for downloading. The red and blue lights on the Propeller Plug flicker as the connection to the PropPlug is opened from the PC and as this conversation begins. For some reason the Propeller is not responding and you've already checked the most common causes.

Parallax is located in California. That's about 8 hours earlier than Paris.

sam_sam_sam

I think I know what your problem is there is a mistake in the wiring digram vers the label for what wire are what do not follow the way the wire are hook up on that page...> follow the label on the Propeller Plug and the label on the board this in Propeller Education Kit version 1.2 on page 27

I had the same problem I follow the wires not the labels

I hope this helps

Marc91

Mike Green wrote: »

For some reason the Propeller is not responding

Is that possible that one of the components I am using is broken ? If so, and with your explainations, it should be the Propeller microprocessor, isn't it ?
Can we imagine a simple circuit to check this point ?

I've tried sam's solution, but in vain. I've made my own circuit following the figure 3-4 on page 27, and the results are the same. But thanks you for the idea.

Rayman

My guess is there's something wrong with the wiring...
Make sure all of the Vdd and GND pins of the Prop chip are connected.
Make sure the reset pin of the Prop is connected only to the PropPlug.
Try posting a photo of your setup... Maybe somebody will spot the problem.

Mike Green

Marc91,
It would be very unusual and unexpected for the Propeller microprocessor to be defective. People have reported that the cause for similar problems has been broken wires, bad cables, a bad breadboard, a bad PropPlug. The simplest circuit to check it would be to borrow someone else's working PropPlug and to use some known good source of 3.3V along with the Propeller chip on a known good breadboard to see if that can be "identified".

Duane C. Johnson

Another thing to do is to simply place a jumper from TX to RX on the PropPlug.
Then, using a terminal emulator, send some characters out and see if they come back.
This will show that the PropPlug is recognized by your computer and what the com port is.

Next, remove the PropStick and put the jumper across pins 39 & 40 of the socket.
See if your characters come back. This checks the connections on the board.

Next, look at the RST pin with a meter. It should be normally high.
When you disconnect and reconnect the com port with your terminal this
line should pulse low for about 100uS or so.
This can't be read with a meter.
To observe this signal use a digital oscilloscope.
Connect a 100K resister between TX and RST.
Watch for the negatively going pulse when disconnecting the com port with your terminal.

Note! I think it's good practice to connect a 100K resister between RST and +3.3V when
when using any of the Propeller variations. The Propeller specifications doesn't say there
is a week pull-up on the chip. So the external resister can prevent accidental resets.

If the PropPlug passed these tests one can be assured it is working properly.

Duane

Marc91

Hi everybody, and thanks for your answers. My computer is now recognizing my Propeller.
What I've done ? I've made for the third time the circuit, and now it's working.
Thank you for your help, you may be right, it should be a wire wich was not at its place ...
Marc