J15Short circuit.
Select 3.3V for system power
JP20, JP22, JP25,
JP26
Short circuit to pin1 & pin2 to each of these jumpers.
These will wire the audio outputs (L & R channels) of LM740 to headphone amplifier.
and then output to J1 phone jack.
JP24 Short circuit to pin2 & pin3.
Select 3.3V for power supply to LM740 module board
JP27 Short circuit to pin2 & pin3.
Select active low Reset for LM740 module board
JP28 Short circuit to pin2 & pin3.
Select 3.3V for the signal level of PIOs of LM740 module board
JP29 Short circuit.
Seelect 3.3V for headphone power supply.
JP30 Short circuit to pin2 & pin3.
Enable the self sustain powering scheme
JP31 Short circuit
Enable 3.3V power supply to the driver ICs of printer port (SPI) and serial port.
On/Off/Pairing Control 1. Pressed and held for more than 2 seconds can turn on/off the module board.
2. Short pressed will set the module board to Pairing mode.
MFB (PIO6) This is multi-function button for A2DP and HFP modes. Please refer to firmware guide of
LM740 RX-HIC version.
Rewind (PIO7) Rewind the music playback (A2DP) of the audio source by AVRCP.
Fast Forward (PIO8) Fast Forward the music playback (A2DP) of the audio source by AVRCP.
Volume Up (PIO11) Turn volume up of the audio source.
Volume Down (PIO12) Turn volume down of the audio source.
System Power Switch Disengage ‘System Power Switch’ that allows the operation of ‘On/Off/Pairing Control’
button
