# Node-red arduino

**URL:** <https://discourse.nodered.org/t/node-red-arduino/45859>\
**Category:** General\
**Created:** [18 May 2021 14:57 UTC](https://discourse.nodered.org/t/node-red-arduino/45859 "2021-05-18T14:57:25Z")\
**Posts on this page:** 11\
**Page:** 1

<div class="post-metadata">

**Author:** ![dick](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dick/32/61180_2.png) [@dick](https://discourse.nodered.org/u/dick)\
**Post date:** [18 May 2021 14:57 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/1 "2021-05-18T14:57:26Z")

</div>

Hello  
\*.ino in Arduino is working well  
The flow for noder-red is ok  
BUT  
There is a communication error with /dev/ttyAMA0 Permission denied.

Is there someone with a solution for that permission denied.  
Dick

---

<div class="post-metadata">

**Author:** ![ghayne](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ghayne/32/39_2.png) [@ghayne](https://discourse.nodered.org/u/ghayne)\
**Post date:** [18 May 2021 15:45 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/2 "2021-05-18T15:45:59Z")

</div>

on the command line type in the following:

```auto
$ ls /dev/ttyACM0 -l

```

On my system I get

```auto
crw-rw----+ 1 root dialout 166, 0 May 17 21:51 /dev/ttyACM0

```

Add the current user to the dialout group:

```auto
sudo adduser current_user dialout

```

so on a Raspberry Pi (If you chave not changed the default user)

```auto
sudo adduser pi dialout

```

You can find out the current user with

```auto
whoami

```

---

<div class="post-metadata">

**Author:** ![dick](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dick/32/61180_2.png) [@dick](https://discourse.nodered.org/u/dick)\
**Post date:** [18 May 2021 17:39 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/3 "2021-05-18T17:39:30Z")

</div>

Thanks

I tried this help

`ls /dev/ttyAMA0 -l`

crw -rw-rw- 1 root dialout 204 64 mei 18 15:30 /dev/ttyAMA0

pi is already member of dialout

Whoami à pi

And the result is negative

Dick

Verzonden vanuit [Mail](https://go.microsoft.com/fwlink/?LinkId=550986) voor Windows 10

 ![1DBDCCB5B6C74A51A4340270580B4443.png](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/1/7159a975d714a6caee787759490140daf4d4fda6.png)

---

<div class="post-metadata">

**Author:** ![ghayne](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ghayne/32/39_2.png) [@ghayne](https://discourse.nodered.org/u/ghayne)\
**Post date:** [18 May 2021 17:55 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/4 "2021-05-18T17:55:08Z")

</div>

Can you post the output of:

```auto
ls /dev/ttyA*

```

---

<div class="post-metadata">

**Author:** ![dick](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dick/32/61180_2.png) [@dick](https://discourse.nodered.org/u/dick)\
**Post date:** [18 May 2021 18:10 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/5 "2021-05-18T18:10:12Z")

</div>

Ghayne

The output is

/dev/ttyAMA0

Hope you can help me with this problem

Dick

Verzonden vanuit [Mail](https://go.microsoft.com/fwlink/?LinkId=550986) voor Windows 10

 ![1DBDCCB5B6C74A51A4340270580B4443.png](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/1/7159a975d714a6caee787759490140daf4d4fda6.png)

---

<div class="post-metadata">

**Author:** ![ghayne](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ghayne/32/39_2.png) [@ghayne](https://discourse.nodered.org/u/ghayne)\
**Post date:** [18 May 2021 18:15 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/6 "2021-05-18T18:15:03Z")

</div>

> [@dick](#):
>
> ttyAMA0

If pi is already a member of the group dialout I have no idea why access to the serial port is denied. Which version of Node-red are you using?

---

<div class="post-metadata">

**Author:** ![ghayne](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ghayne/32/39_2.png) [@ghayne](https://discourse.nodered.org/u/ghayne)\
**Post date:** [18 May 2021 18:23 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/7 "2021-05-18T18:23:30Z")

</div>

> [@dick](#):
>
> ttyAMA0

This is the Bluetooth port on the Pi!! I think you might be using the wrong serial port if you have a wired connection!

---

<div class="post-metadata">

**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [18 May 2021 19:25 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/8 "2021-05-18T19:25:50Z")

</div>

Have a look at this how to setup the port correct:

> **[Configuring The GPIO Serial Port On Raspbian Jessie and Stretch Including Pi...](https://spellfoundry.com/2016/05/29/configuring-gpio-serial-port-raspbian-jessie-including-pi-3-4/)**
>
> The Raspberry Pi GPIO serial port configuration has changed under Jessie / Stretch / Buster and also with the Raspberry PI 3 / 4. How to set it up.

---

<div class="post-metadata">

**Author:** ![dick](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dick/32/61180_2.png) [@dick](https://discourse.nodered.org/u/dick)\
**Post date:** [19 May 2021 06:28 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/9 "2021-05-19T06:28:32Z")

</div>

Ghany thanks again.

Indeed i have a wired connection

ls /dev/tty\* gives the possibility to use dev/ttyS0

I tried /dev/ttyS0 and the error “permission denied “has disapeared .

But now is there a new error:

"serial port /dev/ttyS0 error: Error: Error: No such file or directory, cannot open /dev/ttyS0

Now i am looking for that solution.

Dick

Verzonden vanuit [Mail](https://go.microsoft.com/fwlink/?LinkId=550986) voor Windows 10

 ![1DBDCCB5B6C74A51A4340270580B4443.png](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/1/7159a975d714a6caee787759490140daf4d4fda6.png)

---

<div class="post-metadata">

**Author:** ![dick](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dick/32/61180_2.png) [@dick](https://discourse.nodered.org/u/dick)\
**Post date:** [19 May 2021 06:29 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/10 "2021-05-19T06:29:56Z")

</div>

Edje thanks

In deed i use the wrong port

I wiil try to read and understand your message

Dick

Verzonden vanuit [Mail](https://go.microsoft.com/fwlink/?LinkId=550986) voor Windows 10

 ![1DBDCCB5B6C74A51A4340270580B4443.png](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/1/7159a975d714a6caee787759490140daf4d4fda6.png)

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [18 July 2021 06:29 UTC](https://discourse.nodered.org/t/node-red-arduino/45859/11 "2021-07-18T06:29:58Z")

</div>

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.