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At the beginning of February I dug out one of my Board of Education Rev C educational boards so I could wrap the LCD Bar Graph Demo [BS2] (https://savagechats.com/index.php?topic=76.0). During testing the LCD kept glitching and I couldn't figure out what was going on. So I grabbed another Board of Education Rev C and the same thing was happening, but worse. I finally tracked it down to the power switch.
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I'm not sure if it was oxidation or what was going on, but the power switch was not making good contact at all. These are not a common switch. They are a DP3T slide switch in a fairly small package with mounting tabs.
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Fortunately, I was able to find them at Digikey (https://www.digikey.com/) as part #: 2223-SLW-127787-4A-S-D-ND (https://www.digikey.com/short/zp8qdtpw)
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Once I desoldered the old switch, I was able to replace this on multiple boards. I'm curious if anyone else is experiencing these issues with the switches?
My BOE does not have the power switch. That makes it a bit of a pain in turning it on and off, to modify the circuitry.
(https://savagechats.com/proxy.php?request=http%3A%2F%2Ffiles.granzeier.com%2FDownloads%2FSavageCircuits%2FMyBOE.jpg&hash=51eab34a1f6cfe241a69e9a5ece165c9fc6c744c)
It does, however, have a 3-pin male header, directly beneath the servo connectors, with a shorting jumper. From somewhere in my dusty memory, it seems that this jumper is for choosing the servo power. Unfortunately, I cannot remember what the settings do, and I do not have the manual for this particular board.
(https://savagechats.com/proxy.php?request=http%3A%2F%2Ffiles.granzeier.com%2FDownloads%2FSavageCircuits%2FJumper.jpg&hash=df12d38313a4f7d644b35570136ecb0b97aca4e6)
It's a little hard to see, but the jumper is just left of the X4 servo port. There are no markings for it on the silkscreen layer, or anywhere else.
I have looked for the manual for this, but all I can find on Parallax's web site is for newer boards that do have the power switch.
Do you (anyone) have the manual for the Stamps in Class Board of Education Rev nothing?
Quote from: granz on Apr 30, 2025, 07:26 AMIt does, however, have a 3-pin male header, directly beneath the servo connectors, with a shorting jumper. From somewhere in my dusty memory, it seems that this jumper is for choosing the servo power. Unfortunately, I cannot remember what the settings do, and I do not have the manual for this particular board.
I don't happen to have that manual handy, however the servo header jumper selects whether power to the servos comes from V
IN or V
DD. The idea being that if this is a BoE-Bot, you could select V
IN and run the servos from the 6V input from the battery pack. However, if you're using the BoE on the bench with a 7.5V or 12V P/S, you'd want to use V
DD so as not to overvoltage the servos.
You would also use the V
DD selection for PING))) sensors or other 5V accessories plugged into the servo headers. This is what I did for the LCD Bar Graph Demo originally.
Quote from: Chris Savage on Apr 30, 2025, 09:52 AMI don't happen to have that manual handy, however the servo header jumper selects whether power to the servos comes from VIN or VDD. The idea being that if this is a BoE-Bot, you could select VIN and run the servos from the 6V input from the battery pack. However, if you're using the BoE on the bench with a 7.5V or 12V P/S, you'd want to use VDD so as not to overvoltage the servos.
That is what I thought, but I couldn't remember if the V
IN was with the jumper placed on the left, or to the right two pins.
But then I took another look. On the bottom, the silkscreen shows that V
DD is on the side closer to the voltage regulator. Always remember to read the back page. :-[
V
DD is how my board has been jumpered since I received it.
Quote from: granz on Apr 30, 2025, 10:22 AMVDD is how my board has been jumpered since I received it.
Safest option in any event. By the way, not sure if you saw my reply in this thread (https://savagechats.com/index.php?msg=1675), but your package should be there by the end of the day.
By the way, the power switch on the BoE used to be a source of confusion for students and others because it is labeled, "0-1-2), rather than, "OFF-ON-ON (W/SVO)".
Quote from: granz on Apr 30, 2025, 07:26 AMDo you (anyone) have the manual for the Stamps in Class Board of Education Rev nothing?
https://www.parallax.com/package/getting-started-with-stamps-in-class-help-excerpt/ (https://www.parallax.com/package/getting-started-with-stamps-in-class-help-excerpt/)
Is this what you need??
Quote from: Chris Savage on Apr 30, 2025, 10:41 AMBy the way, not sure if you saw my reply in this thread (https://savagechats.com/index.php?msg=1675), but your package should be there by the end of the day.
I did see that, thanks. Our mail usually comes around 2:30-4:30PM, so I'll check on it later on today.
Quote from: JKnightandKARR on Apr 30, 2025, 11:48 AMQuote from: granz on Apr 30, 2025, 07:26 AMDo you (anyone) have the manual for the Stamps in Class Board of Education Rev nothing?
https://www.parallax.com/package/getting-started-with-stamps-in-class-help-excerpt/ (https://www.parallax.com/package/getting-started-with-stamps-in-class-help-excerpt/)
Is this what you need??
Thanks Joe, I had already seen that in my searching for the manual for my Board Of Education. Unfortunately, all of the BOEs in that manual have the power switch. Mine does not have any power switch (check out the picture of my board, compared to Chris'.)
Quote from: granz on Apr 30, 2025, 01:36 PMI did see that, thanks. Our mail usually comes around 2:30-4:30PM, so I'll check on it later on today.
Tracking says it was delivered to a parcel locked? Does that sound right?
Quote from: Chris Savage on May 01, 2025, 11:49 AMQuote from: granz on Apr 30, 2025, 01:36 PMI did see that, thanks. Our mail usually comes around 2:30-4:30PM, so I'll check on it later on today.
Tracking says it was delivered to a parcel locked? Does that sound right?
That is right. Our mailboxes are all in a unified location about a quarter of a mile from our house, and for packages which are too big for our mailbox, they have some lockers below the mailboxes to hold those packages. Then they leave a key to the locker in our mailbox so that we can get our package.
BTW, I have the package now - we did not go out yesterday, but had some running around that we needed to do today. Thank you.
Quote from: granz on May 01, 2025, 03:26 PMThat is right. Our mailboxes are all in a unified location about a quarter of a mile from our house, and for packages which are too big for our mailbox, they have some lockers below the mailboxes to hold those packages. Then they leave a key to the locker in our mailbox so that we can get our package. BTW, I have the package now - we did not go out yesterday, but had some running around that we needed to do today. Thank you.
Okay, I get it now. For some reason I thought you were more rural. You're welcome. Glad you got them.
Quote from: granz on Apr 30, 2025, 01:39 PMQuote from: JKnightandKARR on Apr 30, 2025, 11:48 AMQuote from: granz on Apr 30, 2025, 07:26 AMDo you (anyone) have the manual for the Stamps in Class Board of Education Rev nothing?
https://www.parallax.com/package/getting-started-with-stamps-in-class-help-excerpt/ (https://www.parallax.com/package/getting-started-with-stamps-in-class-help-excerpt/)
Is this what you need??
Thanks Joe, I had already seen that in my searching for the manual for my Board Of Education. Unfortunately, all of the BOEs in that manual have the power switch. Mine does not have any power switch (check out the picture of my board, compared to Chris'.)
I saw that. I don't have the BOE kit, just the one BS2 with the non change Stamp other then the PDB with the stamps i can change out.