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MClif
New Contributor I
1,003 Views

/dev/ttyMFD1, pin 0 (rx, gpio 130), pin 1 (tx, gpio 131)

Hi,

If you are new to this GPIO stuff read the following:

http://www.intel.com/content/dam/support/us/en/documents/edison/sb/edison-arduino-hardware-guide.pdf http://www.intel.com/content/dam/support/us/en/documents/edison/sb/edison-arduino-hardware-guide.pdf

I am trying to echo text to /dev/ttyMFD1 and use cat /dev/ttyMFD1 to display it, but cat doesn't show anything.

My setup is:

# cat /etc/version: 201606061707

Windows 10 PC with putty installed

This is what I have tried ...

Step 1: Booted Edison

Step 2: Displayed the direction file for the GPIOs associated with pin 0 (rx) and pin 1 (tx):

Looking at /sys/class/gpio

and /sys/kernel/debug/gpio_debug

pin GPIO Direction Value current_pinmux current_pullstrength

0 130 in 0 mode1 2k

216 out 0 *no file* *no file*

248 out 0 *no file* *no file*

1 131 out 1 mode1 50k

217 in 1 *no file* *no file*

249 out 1 *no file* *no file*

Step 3: run the script to do the echos

I used the code in the following:

/thread/57358 https://communities.intel.com/thread/57358

I changed the code so that only "in" and "out" were used.

For my rational see my post # 17 and Yermi's post # 18 here:

/thread/111658?start=15&tstart=0 https://communities.intel.com/thread/111658?start=15&tstart=0

Step 4: Display the direction files again

Looking at /sys/class/gpio

and /sys/kernel/debug/gpio_debug

pin GPIO Direction Value current_pinmux current_pullstrength

0 130 in 0 mode1 2k

216 in 0 *no file* *no file*

248 in 0 *no file* *no file*

1 131 out 1 mode1 50k

217 in 0 *no file* *no file*

249 out 0 *no file* *no file*

The contents of the Direction file (eg: /sys/class/gpio/gpio130/direction ) match what the echo script wanted to do.

Step 4: Use PuTTY to open an ssh window on edison

Step 5: In the ssh window: cat /dev/ttyMFD1

There is no command prompt, which makes sense, since Linux is waiting for something to be displayed.

Step 6: in the PuTTY com4 window: echo Edison > /dev/ttyMFD1

Observation:

Nothing is displayed in the PuTTY ssh window after the cat line (Step 5).

I have spent a long time reading a bunch of discussions trying to figure out how to get this to work.

Question: any idea what I am not doing or doing wrong?

Thanks,

Bill

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5 Replies
idata
Community Manager
117 Views

Hello Bill,

 

 

Thank you for your interest in Intel® Edison Breakout Board.

 

 

Thank you for providing the steps you are following, I'll now proceed to try and reproduce the issue, which may help me suggest a possible solution.

 

 

As soon as I have relevant information, I'll post it here.

 

 

Thank you for your patience.

 

 

Regards,

 

Andres V.
idata
Community Manager
117 Views

Hello Bill,

 

 

Sorry for the late reply, I just wanted to inform you that I am still working on finding a way to display the information in the PuTTY SSH window, it seems to be a more complex tasks than I imagined.

 

 

As soon as I have new information, I'll let you know through this post.

 

 

If you have any update, please post it here.

 

 

Thank you for your patience.

 

 

Regards,

 

Andres V.
MClif
New Contributor I
117 Views

Hi Andres,

I thank you for your effort. I'm glad that it is not something stupid that I didn't do, though there is still a chance of that

The world has worse problems than this.

Thanks for you help,

Bill

MClif
New Contributor I
117 Views

Hi Andres,

I stopped working with this specific topic.

Instead I decided to get a little more involved and I bought and Arduino Uno and connected its pin 0 (rx) to Edison's pin 1 (tx) and vice versa. Eventually got them to talk back and forth after including delays at various spots.

The above brief description won't help anyone without seeing the code. I won't post it here until I am done playing with or until someone asks.

Regards,

Bill

idata
Community Manager
117 Views

Hello Bill,

 

 

Thank you for the update.

 

 

We are glad to hear that you want to share information regarding your new project, the community will appreciate any contribution related to that topic.

 

 

Have a nice day.

 

 

Regards,

 

Andres V.
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