Step 5: TODO: Firmware Commands
Here are a few quick commands to try:
DIR (Lists the files in the current folder)
CD <directory name> (changes the current directory)
VPF <filename> p(lays the MP3 file <filename>)
VP (pause and resume)
VST (stops playback)
V3A (Play all files in current directory)
VF (Skips to the next track)
VB (Skips to the previous track)
VSV <byte> (sets the volume. Valid values are between $00 max volume and $FE min volume - that's hex. That's 0 to 254 decimal. It doesn't say it, but I bet $FF is simply MUTE.)
Now, check out the Vinculum website and download the Vinculum Firmware User Manual. This one manual covers several different firmwares. It is laid out well as a reference if you are already aware of a few things. First of all, most of the firmware varieties are based on the generic VDAP firmware, and special firmwares simply extend upon that. The VMUSIC2 uses the VMSC firmware, which provides commands specific to MP3 playback and communication with the VS1003.
Section 6.8 of the firmware user manual is specific to the VMSC firmware. This is the section you will be most interested in. Sections 6.0 to 6.8 are universal commands, mostly for disk access, file access, and maintenance. There are also some bits of information about using other peripherals in the USB port, such as printers, HID devices, etc.. Table 3.1 lists the various device classes supported by each firmware.
Only port2 is connected on the vinculum, so limit your exploration to that port. It should be noted here that plugging your computer into the USB port on the VMUSIC may result in damage to either the VMUSIC2, your PC, or both. The hardware in the VMUSIC does not support this, even though the VNC1L chip does.
Also, the VMUSIC module should be able to support just about any USB Mass storage device. I have only tried it so far with a USB flash drive, but according to the manual, it should work with USB Hard drives, Cameras (in mass storage mode), card readers, etc... There are some restrictions, however. These are explained in the firmware user manual.
It supports FAT12, FAT16, and FAT32, but FAT32 long filenames are not supported. Sector size must be 512; various cluster sizes seems to work fine. I tested this with an 8GB USB disk with no problems, but some of the commands will not output correct values when the drive is larger than 4GB.
Right now, we are mainly concerned with the VMSC specific commands as well as a few of the VDAP commands (for navigating the file system.)
Again, I will revisit this section to help make some sense of all this. But, you now have enough information to start playing around with your module. I would basically be retyping the user manual, anyway, as it is pretty clear once you know where to look. I have successfully created a text file in the format of an INI file, inserted data into the separate sections, and then read it back one section at a time, all using hyperterminal only. It is very easy and I bet you'll have it all figured out before I even update this!