Re: [Amforth] Flashing AmForth to Arduino Leonardo

[Tristan W. <ho...@tj...>]

Hello Jan, Erich,

I came across my Leonardo and remembered this thread.  I think Eric
is correct. There is no FTDI USB to serial chip. The USB connection is
provided by the ATmega32U4 itself.  The Leonardo bootloader enumerates
to the host as a CDC Class device (virtual serial port). However, once
the Leonardo has been flashed with the amforth hex files there is no
bootloader, and so no serial port via the USB connection. 

If you have access to a USB to TTL serial adaptor (5V) it is still
possible to use the RX1 and TX1 connection to the hardware USART to
host the AmForth interpreter. The file /appl/arduino/leonardo.asm
seems already setup to do this.

> warm
amforth 6.8 ATmega32U4 Forthduino
> unused .
2266  ok
> 

The fuses on my Leonardo were

Fuses OK (E:C7, H:99, L:CF)

Best wishes,
Tristan

On 13Dec18 12:39, Erich Wälde wrote:
> Hello Jan,
> 
> Jan Kromhout writes:
> 
> > Hi,
> >
> > Flashing the Arduino Uno is giving no problems.
> >
> > Try to flash the Leonardo.
> > I’m using the Pololu AVR programmer v2.1
> > This is my command.
> >
> > MacBook-Pro-van-Jan-10:avrdude jankromhout$ avrdude -p m32u4 -c avrispv2 -P /dev/tty.usbmodem00230362 -U efuse:w:0xFF:m -U hfuse:w:0xD9:m -U lfuse:w:0xFF:m -U flash:w:leonardo.hex:i -U eeprom:w:leonardo.eep.hex:i
> >
> > It isn’t working
> > Can someone help me with this problem.
> 
> looking into old files of mine ... 2013-05-01
> 
> I have not succeeded with a leonardo either. Attaching did create a
> serial interface (/dev/ttyACM0), however, after erasing leonardo's
> flash, this disappeared. So maybe usb connection is not through a FTDI
> chip? THIS is a highly questionable idea, be warned. But might be worth
> to check the schematics.
> 
> https://www.arduino.cc/en/Main/Arduino_BoardLeonardo
> https://www.arduino.cc/en/uploads/Main/arduino-leonardo-schematic_3b.pdf
> 
> There is no FTDI, as far as I can see, however, how erasing the
> atmega32u4 flash results in not responding to the ISP programmer, is not
> obvious to me. I succeeded in erasing once. Nothing after that.
> 
> 
> Please note that the _atmega_32_u4_ is a quite different beast from the
> atmega_328p. So fuse settings would be another candidate to check.
> 
> I didn't find my leonardo just now ... so I can't play with it.
> 
> 
> Cheers,
> Erich
> 
> 
> --
> May the Forth be with you ...
> 
> 
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