View Full Version : Propellor proto board switch

02-14-2007, 09:31 AM
· Hi all,

Have been intersted in the Prop when it first came out and have added a demo board and the education kit to my collection .Received my order for the 5 Proto Boards and a couple of the Acessory Packs.I must say that I've never had any problem with the Prop so far and having·Objects that work
really makes it fun to use. I assembled one with the AP and went to test it out (using the prop plug ) .The prop was not seen with the switch in the middle position but it is seen on the end position . Then I tried another Proto Board but it had nothing added to it (bare) . It would not be recognized at either switch position . Then retried the first one and removed the jumper (which I had at the 5V position) and it would not be recognized also.

Am I wrong in thinking that the prop should be running (logic power) with the switch at the center position and that the jumper only controls what voltage source the servos see ?


Paul Baker
02-14-2007, 10:34 AM
Thats odd, the switch has polarity (it can only be inserted one way into the board) and the boards were powered up by the manufacturer. You are plugging the PropPlug with the badge facing upwards? Does the green LED light when its in the right two positions? The jumper position only selects the power for the servos. Do you have a multimeter on hand? Tomorrow I will deduce the proper continuity tests for you to run on your boards. If it turns out they are defective, we will get you replacement boards.

Paul Baker (mailto:pbaker@parallax.com)
Propeller Applications Engineer
[/url][url=http://www.parallax.com] (http://www.parallax.com)
Parallax, Inc. (http://www.parallax.com)

Post Edited (Paul Baker (Parallax)) : 2/14/2007 3:38:59 AM GMT

02-14-2007, 11:31 PM

The first thing I did when I received the 5 boards and 2 Accessory Packs ·was to assemble 1 board . I put the jumper for the servo power at the 5volt selection and just hooked up a vga monitor to test it. Noticed that the prop would not be seen at the center position of the power switch so I tried the end position and it got recognized .Loaded up the VGA demo and it works. So I decided to try a bare Proto Board (no added components ) and was not able to have it recognized at either switch position .So I went back to the first board and removed the servo jumper completely and it too would not work at either switch position . I think why no one has seen this is that most likely they did what I did (populated their board with the AP) and just pushed the switch all the way over. The test for anyone interested would be to remove the servo jumper and see if their board still works. I tried 2 other bare boards and they both refuse to work . I thought that maybe i was missing something (like a jumper for the 3.2 supply needing to be soldered in somewhere ) but did not see anything mentioning that . I would have got back to youlast night but I was at work and it was a little late.


Mike Cook
02-14-2007, 11:38 PM
I ordered 12 boards.

Populated 1 with the accessory part kit and the 3 resistors required for the composite video out. Board works in both switch positions, Logic and Servo, whether or not the servo jumper is installed or not.

After seeing your post, last night, I went through all 11 other ProtoBoards. None of them populated. And made sure that the Propeller Tool would do an 'Identify' (F7). All boards worked.

Take a look at your first board for solder bridges. If I'm understanding, your posts, correctly now you can not get your Prop Plug to work with any of your boards?

Mike (http://www.allsurplus.net/)

Post Edited (Mike Cook) : 2/14/2007 4:57:22 PM GMT

02-15-2007, 12:01 AM
No my proplug works fine . On the populated board It will only 'Iderntify" when the switch is set at the last position and with the servo jumper set at 5volts ( did not try the Vin position) . Just tried all my other boards ( unpopulated) and they are all dead ( led lights up but no communication) . I've got a demo board and have built up the education board to do vga and video plus both PS2's . I thought that maybe a jumper for the 3.2V was missing or something . Kinda strange . I'm sure there has to be a simple explanation for this .


02-15-2007, 12:04 AM
Well, grab a scope or multimeter and scope out the schematic; it is a very simple board.

By the way, I love your handle (Propability).

02-15-2007, 12:07 AM
edit -double post

Post Edited (Propability) : 2/14/2007 5:13:38 PM GMT

02-15-2007, 12:21 AM
Rokicki ,

Thanks for the nod . Yeah I was about to get down to seeing what was going on . No need for the scope just some continuity checking with a meter . I let the 1st board with the VGA Demo run all night long and its still going . Loaded the Demo into the eeprom and and it will boot up but only at the last switch position . I think it would be better to look at a bare board and see why they don't work . I'm sure that this is just something simple on my part .


02-15-2007, 12:52 AM
Propability got me spooked. http://forums.parallax.com/images/smilies/freaked.gif

So decided to test all of my '6-pack'. Yep, they all passed the Identify (F7) test. http://forums.parallax.com/images/smilies/yeah.gif Phew! Sure didn't want to have the hassle of returning any.

Bonus. When the 6-pack arrived, I only reached into a bag and removed the board. Not until today did I do the testing and 'dumped' one into my hand. And there was that strip of 4 rubber feet. Yep, bonus. http://forums.parallax.com/images/smilies/yeah.gif

Nice layout for the Propeller ProtoBoard. And like the helpful silkscreening on the back side; nice touch, Parallax. First saw that on the BS2 OEM boards.

Harley Shanko
h.a.s. designn

02-15-2007, 12:54 AM
O K got it solved ! The wall-wart 9v that works with the Education Board ( with VGA ,video , 2 ps2's ) just does'nt like the Proto Board ( the extra capacitance of the servo circuit capacitor 1000uf would make it work when switched to the servo position) . Dam wal-warts .


02-15-2007, 01:02 AM
Scope the wall wart. It would be interesting to see what the problem is. Sounds like either the wall wart has little to no
capacitance on the output, or that the internal capacitor is fried.

02-15-2007, 02:00 AM
Heres a photo of my Education Board pretty much like a Demo Board ( no stereo or mike) using the same wall-wart that just gave me troubles with the Proto Board . Tried the Demo Board and it too didn't like it . Didn't mean to cause a stir, just sometimes something doesn't add up at first and the obvious is not so.