One Channel 0-10V DAC I2C DAC for Fan Control

Hardware
#1

Hi,

I would like to use this One Channel 0-10V DAC I2C Digital To Analog Converter here:

https://store.ncd.io/product/1-channel-0-10v-dac-digital-analog-converter-i²c/

To control the speed of a fan based on the data collected by another external sensor in raspberry pi.

The fan itself, already has a speed control and terminals for a potentiostat control, 0 to 10 VDC:

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and wiring for an optional speed control (wall mount) here:

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the manufacture of the fan says that if you can provide an analog 0-vdc signal, it will work to control the fan speed.

Hence my interest in this 0-10V DAC control. I did have a few questions:

  1. Being I2C, would it work directly with a GPIO of the Raspberry Pi 3 or 4 or do I need an adapter?
  2. How clean is the power output from the this device?
  3. Having a power boost on board, will this over heat if the voltage is high (say 8 to 10 VDC) for prolonged periods of time?

thanks for your help

#2

Hi,

  1. Yes, it works with RPI.
  2. The board has TI buck boost on the board. The quality of the output voltage depends on the input power supply.
  3. No over heat.

Thanks

#3

Thanks very much!

Will I be needing this adapter to connect it the 0-10V DAC board and the RPI?

And, do I need just these two components (0 to 10 VDC DAC board and I2C shield) to create the desired 0-10 VDC signal to control the fan speed via RPI? It is important that I have access to the full range of 0-10 VDC otherwise I cannot put the fan in full speed. I was reading on another post about having a " PCA9306 I2C Data and Power Level Shifter 0.3VDC" not sure if I will need that also.

Also, what is the difference between the above product and this?

#4

The first part is an I2C shield. it makes wiring easy.

In order to get full 10V you will need to set the input power supply to 5.5V. if you use Pi 5V which stays around 4.8.4.9V you wont get full 10V.

#5

Thanks for your help, so far! I’m still pretty new to this. Ok, Could you please tell me what hardware I need to purchase to be able to get the 0- 10 VDC (or close to it, i.e. 9VDC is ok too).

  1. The shield.
  2. The 0 to 10 VDC DAC board

So, I do NOT need the PCA9306 I2C Data and Power Level Shifter? It sounds like the shield level shifts to 5V, can you confirm?

Which RPI supports 5V? I thought they were all 3.3 V?

thanks again!

#6

Hi,
The only two part you will need is

  1. The shield.
  2. The 0 to 10 VDC DAC board

The RPI shield has level shifter on board so no need to purchase extra level shifter.

RPI has 5V VCC supply. All the logic IO are 3.3v.

Thanks

#7

hi, ahh I see. Ok, I assume the shield will utilize the 5 v pins (i.e. 2 and 4) for its power input.

https://pinout.xyz/pinout/pin2_5v_power

thanks!

#8

also, can you please recommend a good power supply for this setup (RPI 3 or 4, shield and DAC)? thanks

#10

Just curious how the output voltage behaves when changing voltages to different values during a constant “on” scanario. For example if I call for having 6 volt voltage output (constant), the fan speed will adjust accordingly, then say I want to increase the voltage to 7v then on the fly, will it step up to 7 or will it go to zero and then go back to 7. Is the same true for decreasing voltage/fan speed, i.e. From 6v to 4v, for example? thank you