MOD-USB-RS232 Olimex Ltd., MOD-USB-RS232 Datasheet - Page 14

• Manufacturer Part Number: MOD-USB-RS232
• Description: Interface Modules & Development Tools USB TO RS232 INTERFACE MODULE
• Manufacturer: Olimex Ltd.

Specifications of MOD-USB-RS232

• Product: Interface Development Tools
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

- "cnum <index>" - switch the current directory to the one with given <index>, as
displayed with the "L" command
- "." - returns to the parent directory, no higher than the root directory
- "PSONGNAME <name>" - plays file in the current directory by its <name>,
<name> should be in 8+3 format and the only extension supported is ".MP3"
- "pnum <num>" - plays file in the current directory by its <index>, starting from 0.
<index> may be calculated by the sequence number displayed with the "L"
command minus the number of directories in the current directory.
- "OFF" - turns the codec chip OFF, may be executed at any time
- "ON" - turns the codec chip ON, may be executed at any time
These commands have meaning only when playback is started:
- "C - stop playing current file, returns "Stopped."
- "+" - increase volume by 0.5dB step, 0 refers to max volume value, 254 is minimal
value.
- "-" - decrease volume by 0.5dB step, 0 refers to max volume value, 254 is minimal
value.
- "p" - play/pause toggle during playback, returns "Paused"/"Playing" respectively.
- "?" - display information on supported commands.
*Note: All of the commands should be followed by a newline character ('\n' or
"\r\n")!
INPUT/OUTPUT:
Status Led (green) with name STAT1, connected to STM32F103RBT6 pin 2
(PC13/ANTI_TAMP).
Meaning of the status LED (STAT1) activity:
- When in mass storage mode the LED indicates SD card read/write activity.
- When playing a file in MP3 player mode LED is constantly ON.
- When playback is paused in MP3 player mode LED is blinking with 0.5Hz period.
Battery level status Led (yellow) with name STAT2, connected to STM32F103RBT6
pin 3 (PC14/OSC32_IN).
Battery level status LED (STAT2) activity:
- When powered by the battery the MOD-MP3-X indicated low battery level. If
voltage of the battery falls below 3.3V then the STAT2 LED starts to blink.
- If an external power source is connected, then battery starts charging. In this case
STAT2 LED is constantly lit while battery is charging and turns off when battery is
fully charged.
Power-on led (red) with name LED is used by VS1053 firmware and is connected to
STM32F103RBT6 pin 36 (SPI2_MOSI).
Wake-up button, connected to STM32F103RBT6 pin 14 (PA0-WKUP).
Switch with name Joystick with three positions: SW1, SW2 and SW3.
Page 14