Hi All,
I’m using a BG96, on a RAK2013 RPI Hat, and trying to enable sleep mode via AT+QSCLK=1,
This indeed seems to put the modem into sleep mode as the UART stops responding.
I then set to DTR pin to high, however when I drop this back to low, the modem does not seem to wake up as i still can not get any response via the UART interface.
Just wondering if anyone can help?
Thanks
I think you have to use also “wakeup_in”
When entering into sleep
mode is enabled, DTR is pulled up, and WAKEUP_IN is pulled up, the module can directly enter into
sleep mode. If entering into sleep mode is enabled, DTR is pulled down, and WAKEUP_IN is pulled down,
there is a need to pull the DTR pin and the WAKEUP_IN pin up first, and then the module can enter into
sleep mode.
Hi Violrel, thanks for your reply,
Its odd that you mention this because it doesn’t mention this wakeup pin on page 26 of the bg96 hardware design manual. REV 2017, unless that the rev year suggests that this is old information.
It only mentions the sleep command, and pulling up the DTR.
Im unable locate this wakeup pin, would you know specifically what pin number?
Hello
Just pull DTR pin to High to wake up sleep.
Are you using BG96 + other board?
If possible could you please help share you schematic and chech if something wrong?
My email: linkin.wang@quectel.com
B R
Linkin WANG
Unfortunately pulling the DTR to high is not working. How long do you need to set this to high for? And does it need to be set to when in sleep mode?
Does it need to be set low or high before sending the sleep command?
Idealy i’m just trying to find a mode that this modem can be placed in to save as much power as possible, but to manually turn back on in order to receive and check for SMS messages. i’m not sure if sleep mode would be better then power save mode would it?
Yes, sleep mode will save more power.
For DTR PIN, should keep high stage at all if you want wake up from sleep and do some at commands.
B R
Linkin WANG
Still no luck i’m afraid,
I set the DTR to low, then executed the command at+qsclk=1 and the bg96 replied “OK”.
The BG96 then stops responding to UART commands.
If I set the DTR back to high, othing happends, and the bg96 appears to still be in sleep mode, with no response via the UART interface.
It’s better to share you schematic for us to check .
Looks as if there wasn’t enough voltage going through to the DTR, seems to be responding now. Maybe I was using the wrong resistance to lower the voltage from 5 V to 3.3 with this particular raspberry pi board incorporating the BG 96 chip. Thank you for your help everyone.
Hi @toottoot , I have the same issue here and am hoping that you could add a bit more detail to how you ended up solving this with your hardware. I have a BG96 on the RAK8213 mPCIe card, wired to an ESP32.
The DTR pin on the BG96 seems to be normally HIGH (sitting at ~1.4v) so I’m wondering whether it needs to be actively pulled HIGH or if I can just actively pull it LOW and then release it when I want it to be HIGH.
What was the sequence that worked for you to enter and to exit the sleep mode?
Hi mate, that was a few weeks ago now I don’t quite recall as I’ve now gone with a different method, I just power mine down completely and power back up every five minutes to check for messages without using the sleep my commands. I’m pretty sure maybe you just pull the pin down low to 0 and issue the sleep command and then pull it back too high to wake it back up.
My issue was that I wasn’t pushing enough voltage, and maybe I’ve damaged my modem perhaps in fact, try so at your own risk, but I think it might be an undervoltage in the DTR. Be careful cause this could damage it if I’m wrong.
Thanks for taking the time to reply. Yeah we have also been powering the BG96 up/down each time (every 10 minutes) in all our devices for several months now. But the data usage to re-establish the MQTT connection with AWS is fairly high, and we think we would be able to reduce that by around 10x if we can keep the MQTT session alive during that 10min sleep, which appears to require us to use this BG96 sleep mode.
I’ll let you know if we have any progress here. Currently just trying to get this sleep mode working.
Ahh that’s interesting, I havn’t got that far yet in terms of keeping connections alive for that long, but best of luck and thanks for your insight!
I do recall from memory there was some command to turn it on first to go to sleep mode, and at the same time setting the DTR to low, then setting the DTR to high to wake it up. I Think some boards will have different resistors in place on the board, which could effect what voltage to send to the DTR. But yer just be careful not to send to much voltage up there if you know what i mean.