Andy is looking at his code as we speak, I have only asked bits and pieces because he is getting involved. If we determine there is anything wrong with his chip, we will certainly send a replacement.
We've never seen·a PLL·partially fail, so we are trying to determine if it is the chip or something else.
Could we please swap boards? My wiring is about as clean as yours, and the platform works with both code examples that have been discussed on this thread. That way, you'll be able to continue, and we'll be able to examine the problem. (I haven't seen this one before!)
Will this work for you? If so, please use my email link (on the left of this post), and we'll set up a cross shipment.
Andy
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Andy Lindsay
Education Department
Parallax, Inc.
Post Edited (Andy Lindsay (Parallax)) : 8/1/2007 6:09:54 PM GMT
Glub, glub!
All the lifeguards are saving that guy!
Alas, my capacity has decoupled from common knowledge.
(Or more precisely, who's got a schematic of these apparently optional decoupling capacitors? Which go between pin x and y, and probably pin a and b on the other side. Which have the value of what? And they work why? And my pe kit doesn't have them and it works almost all of the time except when I tell it to do something stupid, so I need decoupling when?)
I do not know if it is an oversight. It is possible that the Propeller works happily without a bypass capacitor. But, especially when using one of these breadboards with inevitably long leads, it is good design practice to sprinkle a board with decoupling capacitors. It is not uncommon to see a tiny capacitor close to every IC that contains FF:s, counters, memories - in short any circuit that can be be upset by a transient on the supply lines.
These capacitors used to be in the 47 - 100 nF range. But as clock frequencies go up, the resonance frequency of those capacitors gets close to processor clock, so it is now customary to use lower values. Better process technology (or cricuit topology) also has reduced the current spikes that used to plague fast circuits.
It is possible that the propeller has been so well designed that it doesn't need any decoupling (or bypass) capacitors. That would be another achievment worthy the Prop people. But, other circuits may still need the decoupling. So it is never a bad idea to include them.
There could be a problem with the battery connector... a friend of mine just got his PE kit... and the first thing I did was break his battery connector... right at the plastic.
Comments
Paul, could you please have Jim send him another chip, in case there's something wrong with the one he's using?
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Chip Gracey
Parallax, Inc.
We've never seen·a PLL·partially fail, so we are trying to determine if it is the chip or something else.
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
Post Edited (Paul Baker (Parallax)) : 8/1/2007 5:58:16 PM GMT
Could we please swap boards? My wiring is about as clean as yours, and the platform works with both code examples that have been discussed on this thread. That way, you'll be able to continue, and we'll be able to examine the problem. (I haven't seen this one before!)
Will this work for you? If so, please use my email link (on the left of this post), and we'll set up a cross shipment.
Andy
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Andy Lindsay
Education Department
Parallax, Inc.
Post Edited (Andy Lindsay (Parallax)) : 8/1/2007 6:09:54 PM GMT
All the lifeguards are saving that guy!
Alas, my capacity has decoupled from common knowledge.
(Or more precisely, who's got a schematic of these apparently optional decoupling capacitors? Which go between pin x and y, and probably pin a and b on the other side. Which have the value of what? And they work why? And my pe kit doesn't have them and it works almost all of the time except when I tell it to do something stupid, so I need decoupling when?)
I do not know if it is an oversight. It is possible that the Propeller works happily without a bypass capacitor. But, especially when using one of these breadboards with inevitably long leads, it is good design practice to sprinkle a board with decoupling capacitors. It is not uncommon to see a tiny capacitor close to every IC that contains FF:s, counters, memories - in short any circuit that can be be upset by a transient on the supply lines.
These capacitors used to be in the 47 - 100 nF range. But as clock frequencies go up, the resonance frequency of those capacitors gets close to processor clock, so it is now customary to use lower values. Better process technology (or cricuit topology) also has reduced the current spikes that used to plague fast circuits.
It is possible that the propeller has been so well designed that it doesn't need any decoupling (or bypass) capacitors. That would be another achievment worthy the Prop people. But, other circuits may still need the decoupling. So it is never a bad idea to include them.
What do Paul and Chip say?
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Rich
Thanks to Andy for shipping one out without delay. I'm sending mine back so I will be interested to hear what went wrong.