New design for DIY propeller board

bomber

I came up with a new design for a propeller board. It has:

• 7 remaining outputs put onto a header
• 5 LEDs
• 4 pushbuttons
• 4 servo headers (can be used for other things too)
• 4 High current outputs (L293D)
• 2 piezospeakers
• 2 potentiometers
• basic circuitry for propeller (crystal, power regulators, EEPROM, ect.)

This board could be bought as a solder-it-yourself kit. I have taken some screenshots of the board, schematic, and PCB.

Schematic (I am sorry that it is so small)

PCB screenshot

screenshot of a blank PCB

back of PCB

PCB with components

Duane Degn

I'm curious what the second buzzer is for.

How are you reading the potentiometers? Are you using a sigma-delta circuit or some sort of RC time circuit.

I'm not an expert, but I've read several times on the forum that the leads to the crystal should be short. I don't think you'd want the EEPROM between the Propeller chip and the crystal.

I've also read several times about the importance of having 0.1uF caps close to each Vdd pin on the Prop.

I also think you might have some issues with the width of some of your traces. I'm pretty sure power and ground traces should be wider than what you have.


Do you have a specific application in mind for your board? With the motor and servo connections, I'd guess you're planning on some sort of robot control.

It would probably be a good idea to have a schematic to show the forum so the experts here (I'm not one) can help you out.

Thanks for posting your work.

Duane

bomber

The reason that you have found so many errors is that the software that I used has an auto placer that chose the location for almost every component on the board. The second buzzer is for creating sound in stereo, not mono. An important fact is that the buzzers are piezo buzzers. They have no internal driver circuitry. The pots are being read with RC circuits. The two red rectangles are the capacitors. The application for this board would be a board that would allow a person wanting to learn to program, but who wouldn't want to build the circuits. Aout the traces, the power and ground traces are actually twice the size of the other traces. For some reason it is hard to tell the thicknesses apart.

Duane Degn

bomber, I just noticed this is the "Suggestions to Parallax" forum. I was looking at "What's New" and found your post. I thought this was the Propeller forum.

So is this board something you think Parallax should make and you're just giving them a general idea of what you're thinking of?

Or is this a board you plan to have made for your own use?

If this is a suggestion then all the things I noted don't really matter because the people at Parallax would know how to make a board without problem.

I suppose your software put the two piezo buzzers next to each other? So you probably already know you'd want them separated for stereo sound.

Sorry for the misunderstanding.

Duane

bomber

This is actually a board that I designed in my spare time. I was thinking that it would be a neat idea for them to see it. This was mostly for fun.