HILONC V2 freezes

Hello all,

I’m finishing a project based on HILONCV2(HL), and noticed a terrible issue: sometimes, very often though, the module freezes completely. After some AT commands sent from the host MCU to HL, HL just stops responding! Even a low pulse on the RESET pin does not recover the module!!!

When HL enters this state the VGIO pin is high (2.8V), and the RESET signal is useless! Tried with with 20ms, 100ms and 500ms!

The host MCU sends periodically the AT+CSQ command to check for the signal strength, and HILONCV2 just stops responding. It sends the echo of the command, but never responds!

I admit that the power supply (a LiPo battery) is not as good as it should be: capacity 1000mAh, discharge current 2C (2000mA)! When HL draws the burst current, the voltage drops a little… But shouldn’t it reboot spontaneously if the voltage is too low??

The MCU takes care of many things that can go wrong with HL, SIM card and network status, and when nothing works the RESET does… But if RESET does not do the trick?

For next firmware version I would suggest that when HL reboots due to power issues, a message appears when it reboots!

Anyone has any suggestions?


I found that that this problem happened due to a bug in my code (MCU). I was trying to send data to the HL serial port, before the previous command finished.

However RESET should help in such a case, which doesn’t!