# Oled display bus adress

**URL:** <https://discourse.nodered.org/t/oled-display-bus-adress/18468>\
**Category:** General\
**Created:** [26 November 2019 16:14 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468 "2019-11-26T16:14:35Z")\
**Posts on this page:** 17\
**Page:** 1

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [26 November 2019 16:14 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/1 "2019-11-26T16:14:36Z")

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I found this palette. But it asks for a bus address. default is 60. What do I use?

> **[node-red-contrib-oled](https://flows.nodered.org/node/node-red-contrib-oled)**
>
> Node-Red node for controlling OLED displays

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**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:** [26 November 2019 16:21 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/2 "2019-11-26T16:21:58Z")

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Can you scan the I2C bus?

[https://linux.die.net/man/8/i2cdetect](https://linux.die.net/man/8/i2cdetect)

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [26 November 2019 16:29 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/3 "2019-11-26T16:29:26Z")

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I can but the node asks for a bus address

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/3/381d0d6d0402bcf7c391b190142f19afc0317670.png)

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**Author:** ![bakman2](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bakman2/32/6207_2.png) [@bakman2](https://discourse.nodered.org/u/bakman2)\
**Post date:** [26 November 2019 16:32 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/4 "2019-11-26T16:32:22Z")

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What is the use for the output of the i2cdetect command ?

hint: to determine the bus.

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [27 November 2019 08:24 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/5 "2019-11-27T08:24:50Z")

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Please explain, I don't understand? I can use a command to detect the port?

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [27 November 2019 08:37 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/6 "2019-11-27T08:37:26Z")

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![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/c/cd595e7ff6b6c219f8234c80a383dcd5c44a500d.png)

What does this tell me? 😃

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**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:** [27 November 2019 11:55 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/7 "2019-11-27T11:55:40Z")

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You have 5 devices on your I2C bus. Repeat the scan after disconnecting the oled display and you will know which address the display is. Re-connect and enter the address in the node.  
If it works please reply as it will help others who may come across this problem.

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [27 November 2019 15:12 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/8 "2019-11-27T15:12:35Z")

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It didn't work for me, But I use the grovepi board so maybe that is interfering?

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**Author:** ![Dave](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dave/32/10827_2.png) [@Dave](https://discourse.nodered.org/u/Dave)\
**Post date:** [27 November 2019 16:06 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/9 "2019-11-27T16:06:28Z")

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Usually the default oled address is 3c but you can change the address to 3d on the back by moving the resistor over on the address select pads.

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**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:** [27 November 2019 18:19 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/10 "2019-11-27T18:19:05Z")

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> [@bmeester](#):
>
> It didn't work for me, But I use the grovepi board so maybe that is interfering?

That is something you really should have stated in your original post!

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [28 November 2019 15:44 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/11 "2019-11-28T15:44:56Z")

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I am sorry you are right I am new to all this

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**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:** [28 November 2019 16:46 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/12 "2019-11-28T16:46:53Z")

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Have you tried setting the address to 3c in the node, I think the grovepi just passes the I2C bus straight through.

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [29 November 2019 12:33 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/13 "2019-11-29T12:33:33Z")

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I think you are right. It's not working but it's turning on and giving me all kinds of pixels

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**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [29 November 2019 12:42 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/14 "2019-11-29T12:42:14Z")

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I am trying to inject: json {"size":2,"x":1,"y":1,"text":"Oled"}

This is the node help:

A node that write the inlet string with multiple of font 5x7

Payload should contain the font size (multiple of the original one in 5x7), coordinates where the string starts, and the text itself

size: **msg.payload.size**

abscissa: **msg.payload.x**

ordinate: **msg.payload.y**

string: **msg.payload.text**

Exemple: **{size:2,x:1,y:1,text:"Oled"}**

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<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:** [29 November 2019 13:06 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/15 "2019-11-29T13:06:33Z")

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> [@bmeester](#):
>
> I think you are right. It's not working but it's turning on and giving me all kinds of pixels

The OLED might need to be initialised or cleared.

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<div class="post-metadata">

**Author:** ![bmeester](https://avatars.discourse-cdn.com/v4/letter/b/f08c70/32.png) [@bmeester](https://discourse.nodered.org/u/bmeester)\
**Post date:** [29 November 2019 13:25 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/16 "2019-11-29T13:25:47Z")

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I think so. You were right about the address but maybe it's also not the right library it's using.

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<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:** [29 November 2019 13:49 UTC](https://discourse.nodered.org/t/oled-display-bus-adress/18468/17 "2019-11-29T13:49:21Z")

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> [@bmeester](#):
>
> You were right about the address

@Dave takes the credit for that!