5v to power my Neopixel from Duet 2 wifi
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@T3P3Tony Support for NeoPixel strips on Duet 2 WiFi/Ethernet was added in RRF 3.3.
A signal for controlling Neopixel strips can be output on pin 5 of the CONN_LCD connector provided that you do not have external stepper drivers connected to CONN_LCD. The signal level is 3.3V so you need to level shift it to 5V. A non-inverting 74HCT series gate or buffer such as 74HCT08 can be used to do this.
RGB NeoPixels draw up to 60mA per LED. RGBW ones draw up to 80mA per LED. Therefore the Duet cannot provide enough power for an LED strip unless the number of LEDs in the strip is small (for example 16 RGB or 12 RGBW LEDs). For longer strips you must provide external 5V power to the strip.
In firmware 3.3 the maximum supported number of Neopixel LEDs in a strip is 60 RGB LEDs. Firmware 3.4 and later support up to 60 RGBW LEDs or 80 RGB LEDs.
What does this means.
The signal level is 3.3V so you need to level shift it to 5V. A non-inverting 74HCT series gate or buffer such as 74HCT08 can be used to do this. -
@Karim said in 5v to power my led from Duet.:
What does this means.
The signal level is 3.3V so you need to level shift it to 5V. A non-inverting 74HCT series gate or buffer such as 74HCT08 can be used to do this.This means that the Duet has an output voltage of 3.3V, but neopixels needs 5V.
You need a level shifter to "adapt" the voltage between the two systems. -
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@Karim Yes. I think this should work.
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@cosmowave ok how did I connect this, is there a diagrams for this .
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@Karim Not a diagram, but some infos. Eventually it makes sense to read the infos about the duet3 connection and then the special infos about the Duet2...
https://docs.duet3d.com/en/User_manual/Connecting_hardware/IO_Neopixel_DotStar -
@cosmowave
Connecting NeoPixel strips to Duet 2 Wifi or Ethernet
Support for NeoPixel strips on Duet 2 WiFi/Ethernet was added in RRF 3.3.A signal for controlling Neopixel strips can be output on pin 5 of the CONN_LCD connector provided that you do not have external stepper drivers connected to CONN_LCD. The signal level is 3.3V so you need to level shift it to 5V. A non-inverting 74HCT series gate or buffer such as 74HCT08 can be used to do this.
RGB NeoPixels draw up to 60mA per LED. RGBW ones draw up to 80mA per LED. Therefore the Duet cannot provide enough power for an LED strip unless the number of LEDs in the strip is small (for example 16 RGB or 12 RGBW LEDs). For longer strips you must provide external 5V power to the strip.
So Can I use the pin 5 of the CONN_LCD connector and the have a 5v external power supply.
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@Karim Yes, that should work.
Pin5 of CONN_LCD is only the signal. For the signal you should insert your level shifter.
Don't forget to connect the GND's of your Duet and external power supply, else they are not on the same "level". -
@cosmowave Look at this photo .
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@Karim If your LED's don't need to much current it is ok to wire them directly on the CONN_LCD.
Else you should use your external power supply. -
@cosmowave it's just 3 neopixel for my tool head light.
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@Karim said in 5v to power my led from Duet.:
@cosmowave it's just 3 neopixel for my tool head light.
Should be no problem...
Don't forget the level shifter! -
@cosmowave this is where I am confuse, do I still need the level shifter. I am getting 5v +- and signal from the duet 2 Wi-Fi.
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@Karim The signal port has only 3.3V!
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@cosmowave Thank you . I am waiting for the part.
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Got it working, you don't need a level shifter, 3.3v works for the signal, it's only 3 neopixel
M150 X4 M150 W255 P255
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Minimum signal level for a Neopixel is 0.7xVdd, so while you might be getting lucky that it works (in this moment, at least), saying a level shifter is not needed is incorrect.
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@Karim see https://learn.adafruit.com/neopixel-levelshifter for information on Neopixels and 3.3V logic levels.
There is a newer type of Neopixel LED called the WS2812B-V5 which is specified to accept 3.3V signal levels when using a 5V supply, but they are not easy to find yet.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@dc42 Thank You
