# Hardware PWM Node-Red
**URL:** https://discourse.nodered.org/t/hardware-pwm-node-red/66733
**Category:** General
**Tags:** node-red-dashboard, function-node
**Created:** [21 August 2022 18:21 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733 "2022-08-21T18:21:08Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@Sleep](https://discourse.nodered.org/u/Sleep)
#### Post date: [21 August 2022 18:21 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/1 "2022-08-21T18:21:08Z")
Hi
I'm looking for a way to use fully hardware PWM on my RPi Zero.
I want to control a PWM fan requiring 28 kHz.
The GPIO PWM nodes are software only (?).
Does anyone have a script to control the PWM signal through red node?
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### Author:  [@iiot2k](https://discourse.nodered.org/u/iiot2k)
#### Post date: [21 August 2022 19:21 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/2 "2022-08-21T19:21:40Z")
Hi Sleep,
you can use this module:
This is a 1Hz-150Khz Signal Generator Modul.
They have RX and TX inputs.
Connect only to RX with 9600bps, 1 stop bit.
Send string "F28.0" for 28kHz.
Send string "D050" for 50% duty.
Use serial node in Node-Red.
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### Author:  [@Sleep](https://discourse.nodered.org/u/Sleep)
#### Post date: [21 August 2022 19:41 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/3 "2022-08-21T19:41:56Z")
It's not possible without this additional hardware?
Would it be possible to create the PWM with RPi hardware?
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### Author:  [@iiot2k](https://discourse.nodered.org/u/iiot2k)
#### Post date: [21 August 2022 19:54 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/4 "2022-08-21T19:54:18Z")
You can use this python library that support this frequency:
> **[pigpio library](https://abyz.me.uk/rpi/pigpio/python.html)**
>
> Raspberry Pi Reg. C GPIO library and Python GPIO module and shell command utilities to control the GPIO, including SPI, I2C, and serial links.
But it is not used in any Node-Red node.
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### Author:  [@Sleep](https://discourse.nodered.org/u/Sleep)
#### Post date: [21 August 2022 20:12 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/5 "2022-08-21T20:12:23Z")
I'm completely new to this stuff.
Could you make a script for me and tell me where to run it?
☹
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### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [21 August 2022 20:42 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/6 "2022-08-21T20:42:29Z")
> [@iiot2k](#):
>
> But it is not used in any Node-Red node.
Does [node-red-node-pi-gpiod](https://flows.nodered.org/node/node-red-node-pi-gpiod) use that?
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### Author:  [@iiot2k](https://discourse.nodered.org/u/iiot2k)
#### Post date: [21 August 2022 20:58 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/7 "2022-08-21T20:58:56Z")
Oh yes @Colin, it use the pigpio, sorry.
Node-Red has 4000 nodes and it isn't easy to remember all.
@Sleep I think you can use it for 28 kHz.
An other question: Which hardware do you use for driving PWM fan because the gpio drive only 16mA ?
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### Author:  [@Sleep](https://discourse.nodered.org/u/Sleep)
#### Post date: [21 August 2022 21:42 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/8 "2022-08-21T21:42:53Z")
The node-red software generated pwm is not available for these higher frequencies. I havent figured out how to use the RPis build in hardware to generate 28k.
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### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [21 August 2022 21:56 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/9 "2022-08-21T21:56:34Z")
Yes the pigpiod node uses that Pigpio library which can use hardware pwm, so use that node rather than the default pigpio node
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [20 October 2022 21:57 UTC](https://discourse.nodered.org/t/hardware-pwm-node-red/66733/10 "2022-10-20T21:57:08Z")
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