PropStick not found by Propeller Tool

Jim C

Today I received a PropStick kit, and promptly soldered it all together. As per the instructions, I checked the 3.3v before insterting the Propeller chip. Next, following instructions, I connected the RS232/DB9 port to a PC, via a Keyspan USB/Serial converter. For reference, the Keyspan is on COMM port 5.

Next step, according to the Propeller Tool and the PropStick instructions is to confirm the Propeller can be found by pressing F7. This opens a little box "Propeller Communication" with 5 little circles, but nothing else happens.

According to the Propeller Tool Help, F7 scans available ports for a Propeller, but apparently the PropStick isn't visible

Am I doing something wrong?

Phil Pilgrim (PhiPi)

Jim,

Measure the idle voltage on pin 2 of the DB9. It should be negative. Also, if you have a 'scope or logic probe, you should see a pulse on pin 4 after you press F7, and also on RSTn on the Propeller. If not, download and install the BASIC Stamp editor from Parallax, if you don't already have it, and open the Debug screen to your COM5 port. Click the DTR button on and off. As you do so, you should sees the voltage on the DB9's pin 4 toggle between plus and minus voltages and, again, pulses on RSTn. If pin 4 doesn't change, your USB dongle doesn't support DTR and won't work with the Propeller. If pin 4 does change, and RSTn doesn't get pulsed, check your solder connections on the 10K resistors, the transistor, the 0.01uF cap, and the MAX3232. If pin 4 gets pulsed, make sure you have the right cap installed where the .01uF should be. It should read "103", not "104". If this all checks out, check the voltage on pin 2 of the DB9 at idle. It should be negative. If it isn't, check your soldering on the MAX3232 and its caps.

'Hope this helps. If not, post the results of your tests, and we'll go from there.

-Phil

Jim C

Regarding the PropStick not being found, I have additional info:

I hooked up a USB2SER to another USB port on the PC. Connected TX on the USB2SER to A31, and RX to A30. Connected RES on the USB2SER to RST on the Propeller. VSS was tied to gnd.

This time, hitting F7 gets an actual result, but not the preferred one. A box opens with "No Propeller chip found on any COM port". As an experiment, the TX and RX lines were switched, although the result was the same.

Any ideas?

Jim C

Phil:

Regarding tests you suggested. Using the DB9/RS232 set up, (not the USB2SER) Pin 4 on the DB9 is negative. (about -5.5v). I haven't 'scoped the RSTn pin yet, but using the alternate Stamp Debug window method you suggest, I confirmed that Pin 4 does change to positive when DTR is checked and negative when DTR box unchecked. As for the caps, I'm quite sure the 103 is in the correct spot, as I triple checked that before installation. I'll scope RSTn in the next little while.

But, seems to me most of your tests revolve around the MAX 232. Wouldn't coming at it with the USB2SER work even if the MAX 232 wasn't correctly installed?

Thanks for any ideas.

Currently frustrated,

Jim

Phil Pilgrim (PhiPi)

Hi Jim,

Connecting the USB2SER directly to the Propeller while plugged into the PropSTICK is not a good idea, since you'll get bus contention on the RxD line. That's probably why it wasn't found. I had mistaken the first message you received with the "not found" message. I've never seen the one you got before. But I've got an idea that it may have to do with some driver settings in your KeySpan driver. Open the driver settings window in the control panel, and see if there's a setting for "latency". If so, set it to as low a number as you can. This often clears up communications problems with FTDI's USB/serial drivers. I'm not familiar with the KeySpan parts, but it may help there, too, if such a setting exists.

As a check, if you have a PC with a native RS232 port that you can try the PropSTICK on, please do so. That will at least isolate the problem to either the USB dongle or to the Stick itself.

-Phil

Jim C

Phil:

OK, more info: I took the USB2SER off. Loaded the Propeller Tool into a legacy machine, with an original, legacy COM DB9 port. It took me a while, but I managed to confirm it works (first cable I tried didn't have a wire to Pin 4 for some reason). I then tried to find the Stick, and it worked. Then, compiled, loaded and ran the LED blinker program successfully. Oh, ya.

SO, it's starting to look like either the newer PC is the problem, or it's the Keyspan dongle that's the probem. I looked into the Keyspan software and can't find anyway to change latency, so I'm kind of stuck there. Next possibility is to try to find an old FDTI dongle that I lost somewhere.

I'll tell you, getting this thing up and running is a piece of work: dongles, cables, pull out the old machines (properly suited as door stops), can't have two things connected at once, etc, etc. What about an FTDI chip instead of the MAX232 thing? That kind of surface mount form factor is OK with me. Just takes a little practice...

But, we did get it going. Thanks for your help and your excellent work on the Stick. It's a beauty, and it was fun assembly, too.

Jim

Phil Pilgrim (PhiPi)

Good going, Jim! I'm glad you got it working. I hope you're able to find that FTDI dongle. I'd almost bet it will solve things for you on the newer computer.

And thanks for your kind comments about the Stick!

-Phil

Jim C

Phil:

Found the FTDI dongle. You were correct: it communicates fine with the PropStick. No further need for the original-style serial port.

Thanks for your help

Jiim C