I am looking for some examples of success cases in deepsleep mode on the Sub-ghz radios, i.e., simple external low power circuits that can perform the wake up. Clearly one can go into regular sleep mode and preserver registers, retain timers, interrupt infrastructure, etc. But the cost is 10X the power consumption of deepsleep mode. Suppose you want to put the radio in deep sleep and wake it up in approximately a week plus or minus half a day. Does anyone have an example of a ultralow consumption circuit that can do that? Or other deepsleep examples where total lower consumption was achieved than regular sleep mode?
@tkessler3 An external wake up circuit is not required if you want to wake up after a known period: in this case you can use the internal RTC.
the AX8052F143 comes with two low power modes: deep sleep and sleep.
- Deep Sleep: The microcontroller, all peripherals and the transceiver are shut down. Only 4 bytes of scratch RAM are retained. DEEPSLEEP can only be exited by tying the PB3 pin low.
- Sleep: The microcontroller and its peripherals, except GPIO and the system controller, are shut down. Their register settings are lost. The internal RAM is retained. The external RAM is split into two 4 kByte blocks. Software can determine individually for both blocks whether contents of that block are to be retained or lost. SLEEP can be exited by any of the enabled GPIO or system controller interrupts. For most applications this will be a GPIO or wakeup timer interrupt.
As you correctly mention the lowest power mode is deep sleep consuming 100 nA as reported in the table below (page 7 of the datasheet),
As example of DEEPSLEEP you can generate a project in AX-RadioLab set to TX on Demand with the option “Use MCU sleep instead of Stdby” enabled in kit configuration (as shown below). With this example the AX8052F143 is set to DEEPSLEEP and the low power mode is exited upon pressing of the button on the DVK.
For your specific example “you want to put the radio in deep sleep and wake it up in approximately a week plus or minus half a day.” one may either add an external RTC capable of issuing an interrupt that can be used to drive PB3 and wake the AX8052F143 from DEEPSLEEP, or, use the SLEEP mode and schedule a timed wakeup with the WUT running on the LPOSC.