Hey all,
I have a difficult one (I think).
I want to hack into an MP3 player using its switch interface to control it.
basically i got a normal MP3 player from an electronics store to open up and see if i can do something with it.
It runs of a 1.5V AAA batt.
after opening it and checking voltages from my multimeter. I found out that Side A of the power button it gives 1.4V and on Side B it gives 0V. after turning on, it gives 3.3V on Side A. Side B is 0V again after letting go of the switch (obviously)
thing to notice here is that it using a step up. Why? probably for ttl logic, i guess.
So i think that would mean that side B is being pulled high, right?
if thats true, then the rest of the switches are being pulled low. cuz on one side they have 3.3V and on the other side they have 0V and after pressing the switch, Side A falls down to 0V.
Now i was using a LM1117 which is a 3.3V regulator. and to supply the MP3 player with 1.5V on its terminals i used a 10K Voltage divider to get 1.5V.
Problems:
1) The Mp3 wont turn on with that setup. after testing the voltage, it turns out that as soon as i press the power button, the voltage drops down to 0.9V. thats not enough to drive the player. maybe the voltage divider should be of a lesser value, but then i noticed that the resistors got hot.
2) After putting in the 1.5V batt and keeping the GND common,i turned on the player and then i tried the 3.3V wire coming out of the regulator, and it wont switch it high or low.
What am i doing wrong???
i cant post any pictures yet (cuz i got nothing) well i just started. but i hope that i can get some response from what i've just told.
Thanks
Kam
I have a difficult one (I think).
I want to hack into an MP3 player using its switch interface to control it.
basically i got a normal MP3 player from an electronics store to open up and see if i can do something with it.
It runs of a 1.5V AAA batt.
after opening it and checking voltages from my multimeter. I found out that Side A of the power button it gives 1.4V and on Side B it gives 0V. after turning on, it gives 3.3V on Side A. Side B is 0V again after letting go of the switch (obviously)
thing to notice here is that it using a step up. Why? probably for ttl logic, i guess.
So i think that would mean that side B is being pulled high, right?
if thats true, then the rest of the switches are being pulled low. cuz on one side they have 3.3V and on the other side they have 0V and after pressing the switch, Side A falls down to 0V.
Now i was using a LM1117 which is a 3.3V regulator. and to supply the MP3 player with 1.5V on its terminals i used a 10K Voltage divider to get 1.5V.
Problems:
1) The Mp3 wont turn on with that setup. after testing the voltage, it turns out that as soon as i press the power button, the voltage drops down to 0.9V. thats not enough to drive the player. maybe the voltage divider should be of a lesser value, but then i noticed that the resistors got hot.
2) After putting in the 1.5V batt and keeping the GND common,i turned on the player and then i tried the 3.3V wire coming out of the regulator, and it wont switch it high or low.
What am i doing wrong???
i cant post any pictures yet (cuz i got nothing) well i just started. but i hope that i can get some response from what i've just told.
Thanks
Kam