Chengdu Ebyte Electronic Technology Co., Ltd.
E220-900T30D User Manual
Copyright ©2012–2020, Chengdu Ebyte Electronic Technology Co.,Ltd.
11
5.6.4 Notes for AUX
Table 5-1 Notes for AUX
No.
Description
1
For function 1 & function 2 mentioned above, the priority should be given to the one with low level output, which means if
it meets each of any low level output condition, AUX outputs low level, if none of the low level condition is met, AUX
outputs high level.
2
When AUX outputs low level, it means the module is busy & cannot conduct operating mode checking. Within 1ms since
AUX outputs high level, the mode switch will be completed.
3
After switching to new operating mode, it will not work in the new mode immediately until AUX rising edge lasts for 2ms.
If AUX stays on the high level, the operating mode switch can be affected immediately.
4
When the user switches to other operating modes from mode 3 (sleep mode) or it’s still in reset process, the module will
reset user parameters, during which AUX outputs low level.
5
Due to the characteristics of the LoRa modulation method, the information transmission delay is much longer than FSK. It
is recommended that customers do not transmit large amounts of data at low airspeeds to avoid communication
abnormalities caused by data accumulation and data loss.
6. Operating Mode
There are four operating modes, which are set by M1 and M0, the details are as follows:
Mode
（
0-3
）
M1
M0
Description
Remark
0 Transmission
Mode
0
0
UART and wireless channel are open, transparent transmission is
on
1 WOR
Transmitting
Mode
0
1
WOR Transmitter
2 WOR
Receiving Mode
1
0
WOR Receiver
Supports wake up over air
3 Deep Sleep
Mode
1
1
Module goes to sleep (automatically wake up when configuring
parameters)
Supports configuration
6.1 Mode Switching
Table 6-1 Mode Switching
No.
Remark
1
Users can combine M1 and M0 with high and low levels to determine the operating mode. Two GPIOs of the MCU can
be used to control mode switching;
After changing M1 and M0: If the module is idle, after 1ms, it can start working according to the new mode;
If the serial port data of the module has not been transmitted through the wireless, the new working mode can be
switched after the transmission is completed;
If the module receives the wireless data and transmits the data through the serial port, it needs to finish transmission
before switching the new working mode;
Therefore, mode switching can only be valid when AUX output is 1, otherwise it will delay switching
2
For example, users continuously inputs a large amount of data and simultaneously performs mode switching. At this
time, the switching mode operation is invalid; the module will process all the user data before performing the new mode
detection;
Therefore, the general recommendation is to detect the output state of the AUX pin and switch after 2ms when the
output is high.
