Here is Revision D of the code for the Stamp Tester.· This revision includes the new time period for the BS2PE and the BS2P based on findings by Jeff Martin.· Please update your files.
I see a HUGE potential here, just a few questions:
So has the final schematics been decided? And apparantly there are some doing 8 pin versions, and others doing 16 pin versions, I assume the schematic is going to be the same, and the code almost the same?
·· I was the one who made the 16-pin version.· Plugs right into all my development boards just once, except the BS2p40, and that's 2 jumps.· But it works great.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Chris Savage Parallax Tech Support csavage@parallax.com
I've considered a 8 pin version, however for a BS2P40, it would take 4 jumps. Not what I want to do. I'm likly to build a 16 pin version.
I assume the revision D is the most recent? It seems to be a little "in the raw" so to speak, and that's why I was wondering if it's the most recent version.
Any chance of Parallax making the boards for commercial sale?
·· The hardware and the software are pretty straight forward.· Don't concern yourself with revisions so much as functionality.· All you need to do is build the circuit and you could even write your own version of the code.· I did, since I didn't want to be prompted to moved my board when I didn't need to.
·· All you're looking for is an RCTIME value within the range it should be for functional pins.· If a pin doesn't perform properly it is supposed to result in·a failure handled within the software (PBASIC Code).
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Chris Savage Parallax Tech Support csavage@parallax.com
1 Other thing..... Has a schematic been decided on?
I'm not understanding the "Round Robin" method. I assume if the stamp is testing pin 0 then it uses pin 1 for the ground, then when testing pin 1 it uses pin 0, then if testing pin 2 it uses pin 0, pin 3 uses pin 0 as gnd, and so on, is that how the Round robin method is working? And if so, is that reflected in the code?
How does the stamp tester get it's ground? I can't seem to figure that part out. [noparse]:)[/noparse]
TIA,
Knigtht
Post Edited (knightofoldcode) : 7/15/2005 10:04:22 PM GMT
It does not need a ground as such. The pin under test is an input, while the voltage on the capacitor drops, and the other pins in the round robin are outputs that fix the voltage on the other side of the capacitor. Those outputs are as good as ground.
For example, the pin under test starts off as output HIGH, and all the other pins in the round robin are output LOW, and that arrangement charges the two capacitors connected to the pin under test to 5 volts. With the RCTIME command, the two capacitors discharge through the two parallel resistors, until they reach the Stamp threshold of about 1.4 volts. . The other side of those caps is fixed effectively at ground by the low outputs.
The time to discharge is measured and compared with the expected value. The tests sequence shows that each pin is capable of being an input, a high output, and a low output.
I'l post a schematic as an attachment to this message. Make the chain as long or as short as you want, to test a group of pins. The schematic shows an 8 stage round robin.
The choice of R and C values is not at all critical. I use 100k with 0.01uF, but I think others have different components.
There is also a schematic on page 1 of this thread, 12th message down from the top.
Comments
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Sid Weaver
TWS/RWS RF Modules
http://hometown.aol.com/newzed/index.html
·· I suppose I could've just as easily edited the values myself, but I wanted to be using the exact same code as everyone else...
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Chris Savage
Knight Designs
324 West Main Street
P.O. Box 97
Montour Falls, NY 14865
(607) 535-6777
Business Page:·· http://www.knightdesigns.com
Personal Page:··· http://www.lightlink.com/dream/chris
Designs Page:··· http://www.lightlink.com/dream/designs
·
I see a HUGE potential here, just a few questions:
So has the final schematics been decided? And apparantly there are some doing 8 pin versions, and others doing 16 pin versions, I assume the schematic is going to be the same, and the code almost the same?
TIA,
Knight.
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Sid Weaver
Do you have a Stamp Tester yet?
http://hometown.aol.com/newzed/index.html
·
·· I was the one who made the 16-pin version.· Plugs right into all my development boards just once, except the BS2p40, and that's 2 jumps.· But it works great.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com
I've considered a 8 pin version, however for a BS2P40, it would take 4 jumps. Not what I want to do. I'm likly to build a 16 pin version.
I assume the revision D is the most recent? It seems to be a little "in the raw" so to speak, and that's why I was wondering if it's the most recent version.
Any chance of Parallax making the boards for commercial sale?
Knight.
·· The hardware and the software are pretty straight forward.· Don't concern yourself with revisions so much as functionality.· All you need to do is build the circuit and you could even write your own version of the code.· I did, since I didn't want to be prompted to moved my board when I didn't need to.
·· All you're looking for is an RCTIME value within the range it should be for functional pins.· If a pin doesn't perform properly it is supposed to result in·a failure handled within the software (PBASIC Code).
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com
1 Other thing..... Has a schematic been decided on?
I'm not understanding the "Round Robin" method. I assume if the stamp is testing pin 0 then it uses pin 1 for the ground, then when testing pin 1 it uses pin 0, then if testing pin 2 it uses pin 0, pin 3 uses pin 0 as gnd, and so on, is that how the Round robin method is working? And if so, is that reflected in the code?
How does the stamp tester get it's ground? I can't seem to figure that part out. [noparse]:)[/noparse]
TIA,
Knigtht
Post Edited (knightofoldcode) : 7/15/2005 10:04:22 PM GMT
For example, the pin under test starts off as output HIGH, and all the other pins in the round robin are output LOW, and that arrangement charges the two capacitors connected to the pin under test to 5 volts. With the RCTIME command, the two capacitors discharge through the two parallel resistors, until they reach the Stamp threshold of about 1.4 volts. . The other side of those caps is fixed effectively at ground by the low outputs.
The time to discharge is measured and compared with the expected value. The tests sequence shows that each pin is capable of being an input, a high output, and a low output.
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Tracy Allen
www.emesystems.com
MUCH TIA,
Knight.
·· This thread is several pages long, but if you go back through, there were ASCII schematics at the very least.
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Chris Savage
Parallax Tech Support
csavage@parallax.com
The choice of R and C values is not at all critical. I use 100k with 0.01uF, but I think others have different components.
There is also a schematic on page 1 of this thread, 12th message down from the top.
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Tracy Allen
www.emesystems.com
Post Edited (Tracy Allen) : 7/20/2005 7:52:38 AM GMT