User's Manual

4 Quickstart

4.1 Minimal pin conﬁguration

In factory state, the module is immediately ready for operation in command mode. The fol-

lowing pins are required in the minimal conﬁguration:

/RESET, BOOT, VCC, GND, /RTS, UTXD and URXD. The antenna pad ANT must be con-

nected accordingly in case it is used.

If the module is to be connected to a PC, a converter cable/IC (3.3V TTL to USB) is neces-

sary to achieve interface compatibility. The Themisto-I-EV already implements such a USB

converter to be connected to a PC. Not interpreting the /RTS line of the module as described

in this manual may cause undeﬁned behavior and data loss.

For enabling a quick wake-up (after Standby) the pin WAKE-UP has to be connected.

The lines BOOT and WAKE-UP may be connected via external pull-up / down to a ﬁxed level

according to their description when not switched by a host.

In case of the WAKE-UP pin the external pull-up has to be selected accordingly in compari-

son with the internal resistor of typical 13kΩ.

4.2 Power up

Recommended procedure for starting the module into normal operation:

Set and hold the BOOT and RESET pin to LOW.

After supply voltage is applied to the module and has stabilized, the /RESET pin shall be

tied to LOW level for another ∆t of at least 1ms to ensure a safe start-up when releasing or

applying HIGH to the /RESET pin.

The module will send a

CMD_RESET_IND

UART message as well as pulling the /RTS line to

LOW once it has booted and started the application.

Then the BOOT pin may be either released or kept at LOW level.

If the module is used on a battery-powered system, using a matching reset-IC (or a dis-

crete RC block for a delay) is highly recommended to ensure a correct power up and stable

behavior towards a battery getting empty.

Applying a reset (e.g. a host temporarily pulling the /RESET pin LOW for at

least 1ms and releasing it again to HIGH) after the VCC is stable is also sufﬁ-

cient.