Arduino+Nanonote partial success

Xiangfu Liu xiangfu at
Sun Apr 25 09:08:54 EDT 2010

Hi David

replay is inline.

On 04/24/2010 03:31 AM, David Reyes Samblas Martinez wrote:
> or not total fail ,
> I achieved to read/write from serial port using minicom and ttyS0 at
> 57600, but my joy was early trunkated by the keyboard/serial sharing
> gpio issue,
> when arduino sends a message though serial this is also interpreted a
> dirty-random keystrokes sended back trough serial port so it retrofits
> badly.
> Sending only to arduino without arduino reply nothing is ok both from
> minicom, or using #echo "whatever">/dev/ttyS0
> Only reading is not so ok, I was able to recieve big stream of chars
> sended from arduino but there are holes , bad chars and time too time
> it just stops working , thats using minicom, because #tail -f
> /dev/ttyS0 doesn't work at all
> Options from here:
> A)Surrender, let's face we can only send and act in consecuece using
> ben just as a keyboard or data input to arduino
> B) use ttyS1 instead, until now I think no one here has achieve to
> make it work and is possible that will never do because is posible a
> JTAG port and not a UART

I found this in the JZ4740_PM.pdf Page 195, 196

  0 30 U PWM6 (out) UART0_CTS_ (in)  UART1_RXD (in)  6, 7
31 31 U PWM7 (out) UART0_RTS_ (out) UART1_TXD (out) 6, 7

6. This GPIO pin is not available in Jz4725
7. This GPIO pin is not available in Jz4720

since the Ben NanoNote use Jz4720, then we don't have the UART1 pin out. :-(

> C) Workarround the sharing of keyboard/serial pin, disabling keyboard
> while receiving data, and reactivate the keyboard using a key
> combination , disabling then the reception of data. until you finish
> using de keyboard.

when press [S] while boot:
UART0: works fine.
   the [SHIFT] [ALT] [Fn] will not work at first time. steps like:
     first [SHIFT] + [a] will give [a] not [A].
     then hold the [SHIFT] press [a] again will give [A].
     [ALT] and [Fn] are same.

when not press [S] while boot:
UART0: input will not work. output works fine.
KEYBAORD: works fine

> Due B, and C are totally out of my skills I will do some
> tutorial/demo/video with only sending data to Arduino.
> Regards.
> PD.-Jose Luis Cabra Lopez  this post also some kind of reply to your
> question about ttyS0 reception due I think we share the same issue.

More information about the discussion mailing list