# New MCP23017 PCF8574 All-In-One node

**URL:** https://discourse.nodered.org/t/new-mcp23017-pcf8574-all-in-one-node/60087
**Category:** Developing Nodes
**Created:** [19 March 2022 19:43 UTC](https://discourse.nodered.org/t/new-mcp23017-pcf8574-all-in-one-node/60087 "2022-03-19T19:43:30Z")
**Posts on this page:** 1
**Showing post:** 33

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### Author: ![Joe-AB1DO](https://avatars.discourse-cdn.com/v4/letter/j/f19dbf/32.png) [@Joe-AB1DO](https://discourse.nodered.org/u/Joe-AB1DO)
#### Post date: [13 September 2023 18:16 UTC](https://discourse.nodered.org/t/new-mcp23017-pcf8574-all-in-one-node/60087/33 "2023-09-13T18:16:34Z")

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I imported your flow (thanks for sending) and it works as intended. My MCP23017 is on i2c-3, so all I did was change the bus number and it works perfectly:

If I click on **on\_relay\_00** inject node and then on **on\_relay\_01** inject node, both **relay\_00** and **relay\_01** output nodes are on, as indicated by the status indicator:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/8/8/88e8d5989ff23d6f7e6c5d23882a864fd816b608.png)

So you are saying if you first turn **relay\_00** on, then **relay\_01** , **relay\_00** turns off? If so, that's not what I'm seeing here. As mentioned, I am running RPi 4B:

- OS: raspios Bullseye 64-bit
- Node.js version: v18.17.1
- npm version: v9.6.7
- node-RED Version: 3.1.0

So other than the actual hardware and linux version, not too different. One other thing you could try:

- Open a terminal, go to the directory where you have node-red installed (usually ~/.node-red) and enter **node-red-restart** to restart the server. Then refresh the browser window.
- In the same node-red directory enter **node-red-log** : this is where the nodes output a detailed log. Starting with both output nodes off, when you click on the 2 inject nodes to turn the two output nodes on you should see something like this:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/5/0/50e9836c2533aec3d1942ec5989336c75fdb8502.png)

This shows that the two LSBs of **ip16** (pins 0 and 1) go from 00 to 01 to 11. Do you see anything different? If so, what?

BTW, in the terminal enter `^c` to exit the log.

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