USB Protoboard not responding to _clkmode = xtal1 + pll16x

Rob_W

My newest protoboard usb will blink an led with no trouble, however, when I try using _clkmode = xtal1 + pll16x command preceded by the _xinfreq = 5_000_000 command nothing happens. I have been using the code RC4_ESC4_Demo.spin on another protoboard with no problems. If I comment out these commands, then run the code in PST the program displays as expected and the keyboard takes maybe one or two input keys and continues to run without responding. I expect it not to respond properly without the _xinfreq and _clkmode commands. I changed the pll16x to pll8x and random characters did display in PST.
What I am trying to find out is there a fix for this condition or does the board itself have a problem?

One last thought is that the program runs fine on my QuickStart board using the same cables on two computers, the proto doesn't work correctly on either computer.

Anyone Please Help

Thank You in advance
Rob

PS If no cure is available I will be needing Tiger's wrecking ball

Rayman

Well, the PLL is the first thing usually to fry when you do something wrong (like put 5V directly on any pin, or something like that...).
So, if it works without the PLL (like using the RCFAST mode), but doesn't work with the PLL, then perhaps something damaged the Prop.

On the other hand, maybe your crystal is loose...
It does just pop out of the protoboard... You might try wiggling it a bit and see if that helps.

Rob_W

Thank You Rayman for the quick reply. I tried the wiggle check, this did produce various characters being displayed. I also changed the crystal from another proto board. That produced the same result. I had kept the board in question stored in the original container for the 6-7 months, so I don't believe I fried it in any way.

Thanks Again for the suggestion,

Rob

Cluso99

Just to confirm a few things...

Try the FullDuplexSerial demo to just output some characters to the pc. Use PST (Parallax Serial Terminal) which can be invoked by F12 in PropTool after downloading. Just output a few characters continually (with a delay between to prevent overwriting). This way you will now you have a working pcb. BTW I presume the ProtoBoard still uses 5MHz xtal (some various boards use a 10MHz xtal and require PLLx8).

Rob_W

Thank You for the suggestion Cluso99.
I tried outputting characters, which displayed incorrectly. I also used PLLx8, with no luck.I do know the board will accept a program as I used the output.spin examples to blink leds at various rates. This seems to be the limitation of this board. Also, I tried 3 crystals, all with the same results.
I assume something internal to the chip isn't working, I'm not an EE. I do have a QuickStart board which I will use with the dead Proto. The Protoboard can be a sensor board that the QuickStart communicates with.
This Proto was my backup for another I purchased years ago. The original Proto lost the entire usb connector after many years of service, so I'm not dissatisfied.. I'll just move forward in my quest to build an ELEV-8 using alternate means
Your code RC4_ESC4_Demo.spin worked great on my previous Proto. I should also mention to you that I used the "Just ESC" routine to program my esc's with by setting the value high "2000- max throttle" first then low "1000 - off" I plugged them in one at a time and waited for the appropriate beeps from the esc's. This programmed the throttle range and Lipo mode which is selected by one beep of the esc,s.
Thank You So Much for your help and your programs.
Rob

Cluso99

Rob: Sorry your board is not working correctly. It is quite unusual for the prop to fail like this without some form of error in the first place.

Glad the programs helped. They are derived from others works too (all acknowledged in the source). Look forward to seeing you on the quad threads

Sapieha

Hi Rob_W

It is ProtoBoard eles ProtoBoard-USB

And in both cases have You EXTRA Tantalum caps installed near V-Regulators.

Some of ProtoBoards without that caps had some problems with stability of Voltage to prop that prevented correct function of PLL

Rob_W wrote: »

My newest protoboard usb will blink an led with no trouble, however, when I try using _clkmode = xtal1 + pll16x command preceded by the _xinfreq = 5_000_000 command nothing happens. I have been using the code RC4_ESC4_Demo.spin on another protoboard with no problems. If I comment out these commands, then run the code in PST the program displays as expected and the keyboard takes maybe one or two input keys and continues to run without responding. I expect it not to respond properly without the _xinfreq and _clkmode commands. I changed the pll16x to pll8x and random characters did display in PST.
What I am trying to find out is there a fix for this condition or does the board itself have a problem?

One last thought is that the program runs fine on my QuickStart board using the same cables on two computers, the proto doesn't work correctly on either computer.

Anyone Please Help

Thank You in advance
Rob

PS If no cure is available I will be needing Tiger's wrecking ball

Rob_W

@ Sapieha - Thanks for the caps suggestion. I did measure resistances on both sides of the caps back to the V-regs. They were the same as the older Proto-USB. Visual inspection with a magnifying glass showed no obvious defects as expected. It's unfortunate, The only thing I can think of is the possibility of static electricity damage. I've been careful but anything can happen I suppose.

@ Cluso99 - Thanks again for your help. I do realize the code is derived from many others, to all of whom I am grateful. There are just too many to list in these forums. I appreciate the combined efforts of all Parallax staff and the many private individuals who choose to share their knowledge with others like myself.

Leon

If you think the chip is damaged you could get some Chip Quik and replace it:

http://chipquik.com/

Sapieha

Hi Rob_W.

On new Protoboards >Parallax added 2 extra Tantalum capacitors 10uF bottom on V-Regulators .
Betwen 3.3V trace and GND and 5V and GND if You don't have that ones -- Add them and test ( maybe You still not blown PLL ) and it is only instability in V-Regulators.

You can add all between 10uF to 33uF


Ps. Look on picture in this thread how that Capacitors is placed.

http://forums.parallax.com/showthread.php?138082-USB-port-on-proto-board-or-is-it-my-lap-top&p=1075933#post1075933

Rob_W wrote: »

@ Sapieha - Thanks for the caps suggestion. I did measure resistances on both sides of the caps back to the V-regs. They were the same as the older Proto-USB. Visual inspection with a magnifying glass showed no obvious defects as expected. It's unfortunate, The only thing I can think of is the possibility of static electricity damage. I've been careful but anything can happen I suppose.

@ Cluso99 - Thanks again for your help. I do realize the code is derived from many others, to all of whom I am grateful. There are just too many to list in these forums. I appreciate the combined efforts of all Parallax staff and the many private individuals who choose to share their knowledge with others like myself.

User Name

Leon wrote: »

If you think the chip is damaged you could get some Chip Quik and replace it

Wow, great idea! Just alloy the existing solder with bismuth (to drastically lower the melting point) and then pull the chip off! I've got some indium solder, but bismuth is both cheaper and more effective. (An alternate source of bismuth would be the local Cabella's.) I'm tucking this one away.

Rob_W

@ Leon - Thanks for the link, it may be worth trying if I can make sure the chip is bad, I'm not sure how to prove it is the chip vice anything else. So, I bookmarked the link for the future. For now, it is probably quicker to buy another ProtoBoard in order to continue my project.
@ Sapieha - My ProtoUSB does have those caps installed and I measure continuity and resistances of both boards, not finding anything significantly different between the two. Thank for the advice.

Rob