# Configuring node-red-contrib-i2c - i2cOut settings

**URL:** <https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018>\
**Category:** General\
**Created:** [14 October 2023 03:13 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018 "2023-10-14T03:13:21Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![readw](https://avatars.discourse-cdn.com/v4/letter/r/ac91a4/32.png) [@readw](https://discourse.nodered.org/u/readw)\
**Post date:** [14 October 2023 03:13 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018/1 "2023-10-14T03:13:21Z")

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Hi there,  
I am trying to configure the i2cOut setting in node-red-contrib-i2c. The node is correctly installed and communicating with node red but I am unable to find any information on what the correct parameters should be for the command parameter and send bytes parameter. This is communicating with a DFR0971 to set the output voltage between 0-10v. I have tried randomly sending various parameters that sometimes work and other times don't. If anyone could enlighten me on what parameters i2cOut is expecting that would be great. I have searched the web but found nothing usable or understandable that would help. Thanks..

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**Author:** ![zenofmud](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/zenofmud/32/316_2.png) [@zenofmud](https://discourse.nodered.org/u/zenofmud)\
**Post date:** [14 October 2023 09:35 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018/2 "2023-10-14T09:35:52Z")

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@readw Welcome to the forum. Note: I fixed your title to refer to `node-red-contrib-i2c` you were missing the `i`.

I've never used the DFR0971, but doing a google search I found this:

> **[2-Channel 0-10V I2C Digital to Analog DAC Module Arduino Wiki - DFRobot](https://wiki.dfrobot.com/SKU_DFR0971_2_Channel_I2C_0_10V_DAC_Module#target_6)**
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> Wiki: This 2-Channel I2C to 0-10V DAC module can output a voltage of 0-5V or 0-10V, which can be widely used with most 0-10V devices on markets such as light controllers, inverters, valves, pumps, etc., by Arduino programming.

You should take a read and see if that will help you out.

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**Author:** ![readw](https://avatars.discourse-cdn.com/v4/letter/r/ac91a4/32.png) [@readw](https://discourse.nodered.org/u/readw)\
**Post date:** [21 October 2023 01:35 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018/3 "2023-10-21T01:35:41Z")

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@zenofmud Thank you for your suggestion and correction. I have looked at the but I am unable to relate any of that information to the node-red-contrib-i2c.

Any other ideas on how I can get a 0-10v output from node-red?

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**Author:** ![ralphwetzel](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ralphwetzel/32/53713_2.png) [@ralphwetzel](https://discourse.nodered.org/u/ralphwetzel)\
**Post date:** [21 October 2023 06:33 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018/4 "2023-10-21T06:33:23Z")

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> [@readw](#):
>
> I have looked at the but I am unable to relate any of that information to the node-red-contrib-i2c.

Well. There's a lot of data available from the link that @zenofmud provided! You'll find the [datasheet of the GP8403](https://dfimg.dfrobot.com/nobody/wiki/79daa2f3c729e78f0580b474fe33a5e3.pdf) (which provides you information of the protocol this DAC understands) and an [existing implementation](https://github.com/DFRobot/DFRobot_GP8403) of this protocol (for MCUs) as guideline how things have to be put in order. That should allow you to setup your DFR0971 in NR as well.

> [@readw](#):
>
> I have tried randomly sending various parameters that sometimes work and other times don't.

It looks like a good starting point that you already achieved to get (sometimes) a reaction from the DAC. Would you mind sharing the flow that you've created so far?

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**Author:** ![readw](https://avatars.discourse-cdn.com/v4/letter/r/ac91a4/32.png) [@readw](https://discourse.nodered.org/u/readw)\
**Post date:** [2 November 2023 00:18 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018/5 "2023-11-02T00:18:49Z")

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Hi There,

The data sheet, although very informative, is beyond my level of expertise. The i2C node has four parameters that need to be set. Bus number, (1) which works. Bus address, (91) which works. The "Command" which I can find no information on what it is expecting and the "Send bytes" which I am guessing is the message size in bytes. Again, I can find no information on what should be set here.

The node I am using is very basic, A time stamp, counter and the i2c out which had the four parameters that need to be set. I am seeking some guidance on what I should be populating the "Command" and "Send bytes" parameters. Any guidance would be appreciated.

Many thanks

Warren

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [1 January 2024 00:18 UTC](https://discourse.nodered.org/t/configuring-node-red-contrib-i2c-i2cout-settings/82018/6 "2024-01-01T00:18:57Z")

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