HL6528 Cannot wake up from KSLEEP=1

IoT Modules Legacy HL Series
1

HL6528 Cannot wake up from KSLEEP=1. I’ve tried several way in AT commands mode (bypass CMUX)

  1. Toggle RTS, then send ‘AT’. No feedback received.
  2. Send 0x00, wait for 100ms, then send ‘AT’. No feedback received. (I’ve even tried 1s interval, but still NG)
  3. Send 0x00’AT’ in a bulk. No feedback received.

Here I would like to ask do any sequence or timing I should concerns to?
Or any other method that I didn’t tried as listed above?

Thank you in advance.

2

Hi,

Toggling RTS will not do anything, the unit should just be looking for activity on the serial lines (the clock is runnnig too slow for the unit to be able to samples all of the bits on the UART hence initially just looking for activity).

What firmware are you using? I would strongly recommend running 5.5.22, also I guess you are sending at?

Regards

Matt

3

Hi,

Thank you for your reply.

Firmware version is SIERRA HL6N,003.00 and I sent 00, wait 100ms or even more, then send AT cmd ends with , but no luck to receive any character back. 115200, 8N1, No hardware flow control were set before sleep.

I tried to use HiloUpgrader to upgrade firmware (.pac) in my test unit (not EVK), but it fails in 1st step “Saving Parameters”. It shows bypassed…

Regards
Eriko Leung

4

Eriko,

The saving parameters stage can fall over because of where it is trying to save the file, you need to run it as an administrator.

Regards

Matt

5

Hi Matt,

Run HiloUpgrader as adminstrator, it seems “hangs” at “Detection…” in Saving Parameters.
This status is kept over 8 hours… very bad…

Eriko

6

Hi,
In my case, I am using HL8548 with KSLEEP=1. But after go to sleep mode, It can not wakeup event if I send (0x00) charactor on the UART then wait 100ms.
My solution is that holding the RTS pin as active (low level) during all life time of module. That is it!

7

Try sending something other than 0x00 i.e. AT, my general recommendation is to send this until you get an OK out of the unit then you can then send anything you want.

Regards

Matt