Telegesis (UK) Limited
TG-ETRXn-UG-01-103
23
User Guide
1.04
ETRX1 and ETRX2
©2008 Telegesis (UK) Ltd
ETRXn User Guide (Rev 1.04)
The module will boot up into the power mode defined in register S2A, which by default is set to 0.
Register S29 contains the volatile power mode in which the module currently operates
– see Table
3.
In power mode 3 the microcontroller, radio and timers are disabled, so the module will not respond
to serial commands, over-the-air commands or timed events. Only an external interrupt or reset
will wake it up.
Do not enter power mode 3 unless you are sure you can re-awaken the
module.
External interrupts can be caused by a transition on I/O1 and I/O0 which are connected
to Button 3 and Button 4 of the devboard. Ensure that the appropriate bits of S2E are set to
enable interrupt generation.
On the ETRX2 an incoming character on the serial port can cause an interrupt as well, when bit 5
of S2E is set, but note that the first character causing this interrupt will be lost.
Mode
FFD, COO
MED, SED, no Pan
MCU
Radio
Timers
MCU
Radio
Timers
0
Awake Awake User defined Awake Asleep User defined
1
Idle
Awake User defined Idle
Asleep User defined
2
Asleep Asleep User defined Asleep Asleep User defined
3
Asleep Asleep Off
Asleep Asleep Off
Table 3. Power modes
In power mode 2 the timers will keep running although both the radio and the MCU are asleep.
When a timed action is executed the module will return to its original power mode after executing
the action.
Power mode 1 simply idles the MCU when it is not in use. On a FFD (router) this mode is only
recommended in case of light network traffic and needs to be carefully tested.
Also note that a FFD (router) should not be set at a power mode higher than 1 as this will stop the
device from fulfilling its routing responsibility and may cause strange network behaviour.
5.5.4 Functionality text (S2B-S2C)
S2B and S2C contain text strings of up to 50 bytes that can be used for specific timer events as
described in section 11.
5.6 Device-specific registers (S2D-S35)
S2D
Where the local node is either a sleepy end device (SED) or a mobile end device (MED) this
register will contain the EUI64 of the node‟s parent.
S2E
Defines the events that trigger the interrupts, and enables the use of I/O3 for the PWM output as
described in section 6. Also an optional de-bouncing of the interrupt pins can be activated by
setting bit 4 of this register.
On the ETRX2 the wake-up on serial port activity can be enabled by setting bit 5. By setting bit 6
the module can be configured to output the analogue A/D reference voltage on I/O0 during an A/D
