HTCC-AB01 cannot receive data from other device by serial

#1

Hello everyone。I face a difficult problem。i use cortex-m4 to send data from own serial to the HTCC-AB01’s serial.Moreover，i use line to connect the m4’tx and AB01’s rx.unfortunately,whatever i supply power to each other or use AB01 to supply power to m4.the date i received are all zero

image
image.png1021×471 21.3 KB
。then i find use m4 to supply power to AB01 can have data,but this situation is temporary , maybe a while time go by ,the data cannot receive。so anybody use this way to send data?this problem botheres me two week,i wish anybody can help me solve this problem!

#2

Connected GND between m4 and AB01? Check what the ABo1 get from serial!

#3

yeh，i connected GND between m4 and AB01,but this problem still existed.

#4

Same baud rate and stop-bit configurations?

#5

yes,these things are all examined i promised。

#6

make a test serial connection without loRAWAN. Put the output to a serial monitor!

Check behavior of deepsleep!