Spin Stamp and Parallax Serial Terminal

heliboy

Hi All. I just got some spin stamps because I wanted a small form factor and did not need all the pins. I can program the spin stamp fine using a propplug but I cannot get any output to the PC serial terminal program. Weird !!

The test program is just using FullDuplexSerial to send a text string every second. The program works fine on parallax proto board. Is the spin stamp unusable for debugging ? Or am I just missing something ?

Thanks

Mike G

How about posting your code and setup?

What pins are connected to the prop plug?

Mike Green

The Spin Stamp works fine with a serial terminal. There must be something about how you've hooked it up. If you're trying to use the SIN / SOUT / ATN pins (pins 1, 2 & 3), they're not supported according to the documentation. This is because the voltage swings are not RS232 compatible and may not work with some serial ports and USB to serial adapters. I've used a Spin Stamp on a Board of Education with the USB to serial adapter that Parallax sells and that combination has worked for me. The programming port (PropPlug or PropClip) also worked.

WBA Consulting

Mike, do you mean that Spin Stamp can be programmed straight through the Board of Education as long as you use Parallax's USB2Ser adapter on a Serial version BOE? I will dig out my Spin Stamp this week to try it out if so.

Mike Green

No, you can't program the Spin Stamp through the DB9 connection. You have to use a PropPlug or PropClip. What you can do is have another serial connection through the DB9 connection. You can use that for debugging or data, but not programming.

WBA Consulting

Mike, thanks for the clarification. One thought, if I were to make an adapter for the spin stamp would I be able to add some sort of circuitry to use the 3 native BOE programming pins for the Spin Stamp? Maybe map traces to a header that pokes up through the propclip header openings or use a level shifter or use some transistor based inverting circuits or ? I am just curious as to what it would take to use those three pins to program a propeller even if it requires a ton of modifications.

Mike Green

Other than the difficultly of making changes to a surface mount PCB, sure you could make an adapter that would use the existing DB9 socket on the Stamp BOE for Spin Stamp programming. Have a look at the 3 transistor programming interface shown here. This would be an adapter that sits between the DB9 and the PropClip connections. You'd cut the existing traces from the DB9 socket.

I can think of ways you might place jumpers on the Spin Stamp module from the existing interface transistors to the PropClip connections, but you'd need magnification and really fine tools so you could cut traces on the module and solder fine jumpers to it. I wouldn't recommend it. Hopefully the traces don't run under the processor chip.

WBA Consulting

Thanks Mike. I reviewed the schematic and it does seem fairly simple to create a Propeller compatible programming connection from the Sin, Sout, and ATN pins on the BS2 socket. My idea was an adapter that would sit like a DIP socket between the Spin Stamp and the BOE. All other pins would be be pass through, but the Sin, Sout, and ATN pins would be routed through some circuitry and then to the propclip holes via a 4 pin header. If I put the 3 transistor interface on this adapter board between the Stamp's pins (Sin, Sout, ATN) and the Propclip's pins (Rx, Tx, RESn, and GND) it should work fine. I think I will pull out the BS2 from my Board of Education and run wires from it to my PE Kit breadboard to try it out.