Digital potentiometer volume switch - solution verification

This project is used to verify the solution verification board design of the video and audio interface chip PT2259-S of Lichuang Mall .

This project is a sample project for the Solicitation Order for Lichuang EDA open source hardware platform solution verification module .

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This design is an electronic volume control scheme based on N76E003AT20 microcontroller controlling PT2259-S.

It consists of a microcontroller, an electronic volume chip, an encoder, a 5-level LED indicator, a two-color status LED, and other components.

Realize the function of audio signal input and output volume adjustment through the encoder. Get rid of the rustling sound caused by ordinary potentiometers.

Expected functions:

When powering on for the first time, it is in standby state (to simplify the operation, there is no shutdown state, standby means shutdown), L6-L2 does not light up, and L1 lights up with a red breathing light.

Press the middle button of the encoder once to power on, L1 turns to solid green, and the preset volume is read at the same time. The preset volume flashes 3 times in 1 second, and the volume increases from 0 to preset L6 in the next 1 second. L2 increases steplessly to correspond to the volume scale.

In the power-on state, press the middle button of the encoder once to enter standby (power off), save the current volume, L1 turns into a red breathing light, and the output volume is directly turned off to obtain the fastest muting speed. Within 1 second, L6-L2 decreases steplessly from the corresponding volume scale to completely extinguished.

When the volume is turned on and the volume is rotated to the lowest 1-step volume (no 0 volume at boot, to be determined), L1 green light flashes, L6 maintains the corresponding 1-step volume brightness, and L5-L2 are all off.

When the volume is turned on and the volume is rotated to the highest volume, the L1 red light flashes and L6-L2 are all on.

The highest, lowest, and one more rotation are locked, and the two functions are automatically activated. To release, you need to rotate 1 grid in the opposite direction to prevent the encoder from accidentally triggering. This ensures normal operation of the function without affecting the actual operation.