In my build I use a BT909 module on a Shtok PCB. I wired it according to Page 18-19 of the Proffie Manual with a simple switch AND a 47uF 6.3V capacitor between 3.3V and GND.
My reasoning for this is, that I will not always need the BT and therefore want to be able to manually turn it off completely, but when I do, I want it to also IDLE OFF.
(If it helps I also have a 33kOhm pullup resistor on the otherside of the 3.3V to D1 for more precision in the blade ID department)
In general it works, but I get two odd sound issues that I want to take care of, if possible.
- BT-switch is ON and Power is OFF (battery is out)
- When I plug-in the battery the first time (or plug in the USB cable) the boot sound is missing
- I hear the speaker doing something but immediately stops
- Now I can either unplug and replug the battery and the boot sound plays, or I can ignite the blade and the sounds are back
Could the bluetooth somehow be “sucking power” from the SD when turning on?
- BT-switch is OFF
- I plug-in the battery (boot sound plays perfectly normal)
- I switch on the BT-switch
- When igniting the blade no sound plays, when I try switching fonts I get one of two different error messages: “Font directory not found” or - which I find even stranger - “Font directly too long” (it switches fonts but without sounds)
- To get it back to working I could either un- and re-plug the battery, or connect via forcesync App and hit the “refresh” button in the middle of saber and mobile phone graphics.
Might this be “normal” behaviour for instance if it wasn’t properly initialized? But it would still be strange, that it messes with the font directory in that way.
Here is my current config: