Build a simple DAC for your Arduino

Very useful concept if you can't use directly PWM to an external device (e.g. video light)

This looks really useful and looking forward to making one. Is the circuit diagram for Arduino none Due? Does the Due DAC mean that it's output is already converted? I've not got a rail-to-rail op-amp to hand to try it today!

I want to build this project with modifying the variable from 0 to 400. Do i need something different for this case ?

i am building the project for my final year , it has helped me understand the concept well... thnks

Hi, thank you for sharing this circuit. I've built some low pass filters with your tutorial here which are used for my master thesis. The professor was giving me some input for improvement which I wanted to share with you: First you need to think about how much current your load will take. If it is less than 20 mA (Arduino Uno) you don't need an active filter, just a capacitor and a resistor are sufficient. https://playground.arduino.cc/Main/ArduinoPinCurrentLimitations Second and more important I was told not to use electrolytic capacitors for filtering purposes. This type of capacitor is not really stable in capacity. The pro is a huge capacity and the cons are polarity (for a filter), temperature and time dependency of capacity. Electrolyte cap. are only used for power sources, because a change of capacity does not really matter when used as buffer BUT here when used as a filter, in the worst case the amplifier gets damaged. So you should use a unpolarized capacitor with maybe 2.2 µF and then adapt the resistor to 33 kOhm to get the same time constant. Some links: https://forum.allaboutcircuits.com/threads/capacitor-types-and-active-filters.31950/ https://electronics.stackexchange.com/questions/310512/effect-of-capacitor-type-in-an-active-filter-circuit https://www.electronics-tutorials.ws/filter/filter_5.html Regards, Klaus

I replaced the tlv 2451 to OPA350PA and I'm not getting the output DC of 2.5V. The OPA350PA is a rail to rail op amp.

Without a circuit diagram, its hard to exchange the op-amp with another chip...

I'm a bit rusty with hardware but this looks like a standard, active, low-pass filter. On the op amp package pin 3 is non-inverting input, pin 2 inverting, pin 6 output, pin 7 +ve, pin 4 -ve https://photos.app.goo.gl/pkSknnJS3L9hir9P8

I want to build this project with modifying the variable from 0 to 400. Do i need something different for this case ?

Interesting idea for a programming exercise. But unfortunately the processor is fully mobilized with the analogWrite() instruction, which "sequesters" the timer which is also used for millis () and other functions. We are at an impasse if the processor must do many other tasks while continuously generating the DAC voltage. In practice, the arduino board is transformed into an approximate DAC. Given the price of 2 to 3 € for an MCP4725 module (12-bit DAC), why deprive yourself of it, you have to be rational !

Hi, thank you for sharing this circuit. I've built some low pass filters with your tutorial here which are used for my master thesis. The professor was giving me some input for improvement which I wanted to share with you: First you need to think about how much current your load will take. If it is less than 20 mA (Arduino Uno) you don't need an active filter, just a capacitor and a resistor are sufficient. https://playground.arduino.cc/Main/ArduinoPinCurrentLimitations Second and more important I was told not to use electrolytic capacitors for filtering purposes. This type of capacitor is not really stable in capacity. The pro is a huge capacity and the cons are polarity (for a filter), temperature and time dependency of capacity. Electrolyte cap. are only used for power sources, because a change of capacity does not really matter when used as buffer BUT here when used as a filter, in the worst case the amplifier gets damaged. So you should use a unpolarized capacitor with maybe 2.2 µF and then adapt the resistor to 33 kOhm to get the same time constant. Some links: https://forum.allaboutcircuits.com/threads/capacitor-types-and-active-filters.31950/ https://electronics.stackexchange.com/questions/310512/effect-of-capacitor-type-in-an-active-filter-circuit https://www.electronics-tutorials.ws/filter/filter_5.html Regards, Klaus

I'm a bit rusty with hardware but this looks like a standard, active, low-pass filter. On the op amp package pin 3 is non-inverting input, pin 2 inverting, pin 6 output, pin 7 +ve, pin 4 -ve https://photos.app.goo.gl/pkSknnJS3L9hir9P8

Without a circuit diagram, its hard to exchange the op-amp with another chip...

I replaced the tlv 2451 to OPA350PA and I'm not getting the output DC of 2.5V. The OPA350PA is a rail to rail op amp.

This looks really useful and looking forward to making one. Is the circuit diagram for Arduino none Due? Does the Due DAC mean that it's output is already converted? I've not got a rail-to-rail op-amp to hand to try it today!

Very useful concept if you can't use directly PWM to an external device (e.g. video light)

i am building the project for my final year , it has helped me understand the concept well... thnks