7
Trigger Circuit
When the engine is in manual trigger mode, pull down the nTRIG pin will activate the engine to read.
Host Interface External Circuit
When using EM2037, please refer to the below circuits for connection.
Interface Circuit for Decode LED
nGoodRead signal is the LED for a good read, which should be connected to Resistance R4. The brightness of LED depends on the
resistance value of R4. Users can select a resistance value as per need.
T7
Volt_T
LED
D1
R4
1k
nGoodRead
SYS_5V
Interface Circuit for Beeper
nBEEPER signal is the beep for power on or good read. This pin should be connected to Resistance R5. Meanwhile a schottky diode
D2 should be connected to the other end of beeper so as to avoid back-emf rising from no work of beeper.
