Questions about serial to propeller circuit (no MAX232)

[Dennis Ferron]

I don't have any money right now but I have a lot of discrete components on hand, so I thought I'd build the serial to propeller circuit given here:

www.parallax.com/dl/docs/prod/prop/SerialtoPropeller.pdf (http://www.parallax.com/dl/docs/prod/prop/SerialtoPropeller.pdf)

The thing I'm wondering is, that can be used to program the Propeller, but does the circuit also allow the Propeller to transmit serial data back to the computer so that hyperterminal can receive communications?

[David B]

Yes! I've done it.

What I did was to load my spin program in EEPROM, then shut down the Windows propeller tool to free up the Windows COM port, then start HyterTerminal, then restart the propeller board so it reboots from the EEPROM.

Then the newly started spin code is free to send or receive whatever RS232 data it wants, and you can see it on HyperTerminal.

David

[Beau Schwabe (Parallax)]

Dennis Ferron,

You could try the modification mentioned here, that would allow the Propeller to transmit.

http://forums.parallax.com/showthread.php?p=610217

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe (mailto:bschwabe@parallax.com)

IC Layout Engineer
Parallax, Inc.

[The Fat Kid]

I did mine on strip board and it works.· It's messy and it's ugly, but it works.

[M. K. Borri]

I use a 74HCT14 shcmitt trigger inverter for the level shifting and so on... works fairly happily. :)