USB to UART on multi-UART AVR

[Admin]

I am wiring up a circuit for the ATmega2560.

My end goal is to use USB to bootload the ATmega2560.

USB -> CP2102 USB to UART adapter -> UART of ATmega2560

The problem I have however is that the ATmega2560 has four UART's! Would it matter which one I use? My guess is no . . .

Also, possibly related but not sure, what does WR (PG0) and RD (PG1) do on this AVR?

And what is the difference between the CP2102 and CP2103 other than the ~40% difference in price?

[JonHylands]

I can answer the last question - the CP2103 has some (4, I think) general digital I/O pins that can be controlled.

I suspect which UART you use will depend on the bootloader.

- Jon

[Admin]

ok, browsing around I found this:
http://www.ifas.htwk-leipzig.de/easytoweb/indexe.php?content=download

According to the manual, the software has "macros [that] allow the configuration of the data communication."

They have an example that shows me how to define which UART I want and baud rate using some form of GUI. Looks easy!

Just to make sure I understand this right, I upload the .hex bootloader using a programmer (MISO/MOSI stuff). Then to upload future programs, all I need to do is upload a different .hex using the UART, correct? Would I need to add anything to that second program, or can it run just as it was as if there wasnt a bootloader?

And I can use hyperterminal to upload the program while in bootload mode, right?

(only robotics can make me feel like a daily noob )

[JonHylands]

How the second program is uploaded depends on the bootloader. Some of them work with the ASCII hex files directly, so you can upload from HyperTerminal. Some require a custom application (command line or GUI) to upload over the serial port.

- Jon

[Admin]

If HyperTerminal doesnt work, I know how to use AVR Dude (command prompt).

[Graynomad]

what does WR (PG0) and RD (PG1) do on this AVR?

This chip can address external memory, the RD and WR pins are used for that.

[GearMotion]

what does WR (PG0) and RD (PG1) do on this AVR?

This chip can address external memory, the RD and WR pins are used for that.

______
Rob

Timely.

[Graynomad]

He he, yes I didn't notice the date until after hitting the go button. No matter, maybe the OP is still interested  

[Admin]

He he, yes I didn't notice the date until after hitting the go button. No matter, maybe the OP is still interested  

lol yeap still interested. Funny thing is, I never did figure out what it was! thanks