Hi, I have made a custom board and everything is working perfectly. However, there are two pins GPIO25 and GPIO26 which are connected to external interrupts. They are not working. Later I removed all connections and found that these two pins are DAC pins and by default they output ~2v. I am using A…

No. They're internally configured so. The design structure is composed of integrated resistor strings and a buffer. This dual DAC supports power supply as input voltage reference. https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf

I have other development boards on which I can control the pins 25 and pins 26. On the custom board, I cannot configure it. When I try writing dacWrite(25, 0) or dacWrite(25,255), the output voltage will be 0.1v and 3.28v accordingly. This means the pins are working correctly. However, I cannot set …

When ESP32 Core, will be set GPIOMUX correctly at pinMode. It's strange that the DAC isn't disabled. I have multiple lots of ESP32 now and the GPIO is setup correctly in pinMode... What if you manually set the MUX from RTC to GPIO?

Can you please confirm how do I do it in Arduino? All other pins are configured correctly.

[image] praveen_khm: how do I do it in Arduino? Test this. My ESP32 works fine. void setup() { /* pinMode(25, OUTPUT); pinMode(26, OUTPUT); // It has been replaced by below. */ ESP_REG(0x3FF44024) = (uint32_t)0x6000000; ESP_REG(0x3FF48484) = (uint32_t)0xC0000800; ESP_REG(0…

Thanks for the suggestion. However, this is not working. It still says 1.9v. Can you please confirm what is this trying to do? I need to know if there are any registers that disable DAC in ESP32?

[image] praveen_khm: I need to know if there are any registers that disable DAC in ESP32? If you know the what is register, please check the register map by yourself in the reference manual. Open documents, and into serach window my code's adress. By the way, that code also sets the DAC1/2 …

In addition, I've tried with three board of ESP32 I have. First I had fun with pinMode(25, ANALOG) and dacWrite(25, xxx). Yeah, sounds good. :relaxed: After few delay() I put the code I posted and digitalWrite() loops. They back to working properly with digitalWrite(). :wink: Sorry, I don't kno…

Well. I guess it should be a bad module. I will solder another esp32 module on another PCB and recheck. Even then, I learnt a lot of stuff from your suggestion. One weird thing is when I write a voltage to pin 25 (dacWrite), pin 26 reflects same voltage. For example, if I write 125 to pin 25 and 25…

[image] praveen_khm: I will solder another esp32 module on another PCB and recheck. If possible, please report the results after doing that. It good rewards my suggestion. :relaxed:

Disable DAC Pins on Pin 25 and 26 on ESP32

Other Hardware 3rd Party Boards

chrisknightley July 9, 2021, 6:13pm 11

If possible, please report the results after doing that.
It good rewards my suggestion.

Topic		Replies	Views
Arduino Nano ESP32 DAC pin General Guidance	10	1860	July 22, 2024
Esp32 dac resolution Programming	19	266	December 23, 2025
Pin Location for Arduino ESP32 Nano DAC Nano ESP32	1	237	November 6, 2024
ESP32 pin misbehaving - is it me or Wokwi? 3rd Party Boards	9	259	May 20, 2026
ESP32 - does setting pin mode to output clear pull-ups? 3rd Party Boards	22	475	May 22, 2026

Disable DAC Pins on Pin 25 and 26 on ESP32

Related topics