Hello,
how exactly differ individual sleep modes of BG770A-GL? According to AT+QSCLK documentation 0 disables sleep mode and 1 or 2 enable it.
My experience with BG770AGLAAR02A01_01.202.01.202 firmware (w/o PIN_TRIG functionality):
Using mode 0 the module can go to PSM - I receive +CEREG: 4 followed by +QPSMTIMER: 90000,0 and PSM POWER DOWN. Afterwards VDD_EXT is turned off. Later I can wake up the module using PWRKEY.
Using mode 1 or 2 I never receive PSM URC messages, the last one is +CEREG: 4. The documentation mentions that I might not receive them which is fine. But in these modes VDD_EXT stays on and the module does not respond to PWRKEY or MAIN_DTR, only RESET_N works.
What is the proper way of waking up in sleep modes 1 and 2? The documentation only explains PWRKEY wakeup - HD chapters 3.5.2 and 3.11.1.2. And it does not work in these sleep modes.
I didn’t test it with R01 firmware, only R02.
I am using the BG770A in R01 (not R02) . We also had problems with PSM
( BG770A-GL: Safe way to exit PSM prematurly? ), which were not solved (using AT+CPSMS seems no practical solution). However because in our Application wakeup is not very ofter per day, we decided to only use Power-On/Power-Down.
But please keep me informed if you find a way to exit PSM (and + CEREG: 4) in another way.
Best regards, Jo
Btw: would you be interested in a technical cooperation? Our device is a minimum solution with 2 * AA 1.5V Standard Alkaline/Li-Batteries, which includes a simple serial bus (SDI-12) and a 1-16 MByte Memory with a filesystem. As CPU we are using an NRF52 with FOTA over Mobile or BLE. With this we are able to do 3000-5000 Transmission per battery set (https). We also have a PWA (Javascript) for local access. Our company (Southern Germany) is very small, we mainly develop for scientific climatology projects.
I can use PSM, but only with AT+QSCLK=0. It is still better than power-cycling the device and during registration all over again.
To get longer battery life we use NB-IoT where we can get 20-50k transmissions per one pair of AA alkalines using UDP communication.