Been playing with this for a while now and cannot seem to get the DY-HV20T to do anything for me using UART commands. It plays in regular IO mode so I know the audio output works.
When I send a command it just seems to echo the command back, not sure if I am doing it right. I found little bit of documentation on the web but it is scattered. There seems to be a lot more information on the DY-SV17F but the commands seem to be similar.
At the moment I am just trying to send the commands using a USB to serial and an application called Serial on a MacBook. I attached a screenshot in hopes that someone could offer some advice.
Is 9600 the Right baud rate?
Is there a specific magic incantation to get the device in command mode?
GND wired properly? 5V device? Tx and Rx crossed?
I'm not able to upload the manual because I am a new user but it can be found here.
It shows 9600 baud, 8 bit with 1 stop bit. The magic incantation should be AA and I think I have it hooked up correctly. When I unplug the rx on the usb-serial from the tx on the device I no longer get any kind of response in the terminal window. It doesn't seem to matter what kind of command I sent it, I get an echo followed by 0d.
There is also an Arduino library I have been gleaning information from here
