microcontrollermp3
i'm sorry for asking a stupid question, but currently i'm making a simple mp3 player with yx5200-24ss chip. Please read the attached schematic below:
Is it alright if i'm not using pin 15 and pin 16 (adkey1 and adkey2) as shown in the schematic above? For i plan on using mcu to control the ic. Will it working properly without a 22k resistor between vdd io and the addkeys pins?
By the way this ic used in DFPlayer Mini
thanks.
You likely have a ground loop, between the chips GBUF and the speakers GND, caused by the speakers power supply. Note the SFE MP3 player is like your referenced vs10XXan_output.pdf Section 2.1 Figure 4 or 5 (minus the ESD).
Note the GBUF (the return of the headset) is not GND. The VS1053's output is likely a Class D amplifier. Hence it's switching at high frequency, in reference to the return (or GBUF). Section 3.2 recommends that when the VS1053 is driving a amplifier, it requires the addition of C1,R1,C2,R2 as shown in figure 8.. The SFE MP3's schematic does not have these. leading to some complaints, such as your.
The SFE MP3 and UNO with a no-name amplified speaker set works for me. But I believe my speakers have AC isolation within, as it only has hot and neutrual and no ground, yours likely has some connection to ground. Hence you are hearing the switching across GBUF. Additionally there are warnings stating this can be harmful to the amplifier.
Until SFE changes their design, the only solution is either a isolated amplifier or hack a cable to include the addition AC coupling (aka R's and C's).
Regardless the VS1053 and its open source Library are a great companion for the Arduino. I have seen many successful projects using it.
You should use a signal processor or severals signal processors with MP3 playback capability to do this task. Note that MP3 has a quite a long setup time from start of decoding to hearing sound at the output, and also MP3 decoding is quite an expensive operation in DSP, using quite a lot of memory. This design would be much simpler by using a non-compressed audio format such as PCM.
Best Answer
If you aren't going to implement any of the keys, then the value of the pull-up resistor isn't critical, but you still need something to keep the line high. If it's allowed to float, the chip may read errant key presses.
You might even be able to get away with connecting ADKEY1/2 directly to the 3.3V rail, but I'd be a little wary of doing that.