RAK5802 Power On/Off

WisBlock
1

I’m testing a RAK4631+19007 with RAK5802

after testing the examples I could power it with WB_I02 which works just fine for RS485 connection.

But then , trying to power it off (with the same WB_I02 pin), and then going into deep sleep, the board still consumes more than 2,8mA.

Is the RAK5802 always powered from 3.3V ? or from WB_I02 ? or from another pin?

2

The RAK5802 is powered through 3V3_S which you can control with WB_IO2, but you might need to de-initialize the UART, as both RX and TX are connected with pull-ups to 3V3_S, which can lead to powering 3V3_S through the RX or TX lines when they are kept on HIGH.

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3

now it gets complicated

RAK4631 + RAK19007 + RTC RAK12002 (in SLOT-A) gets me into the 30uA at deep sleep

but when I use also the RAK5802 (IO_SLOT) i have to use WB_I02 … which is also used for interrupt on the RTC board.

So trying to use WB_I01 as interrupt did not go as expected… (RTC or something make it reboot right away and not because RTC)

Then using RTC (only without RAK5802) in SLOT_C worked with WB_I04 (WB_I03 not), but the current was not low enough compared to using only the RTC in SLOT_A.

is there really a way to use SLOT_A with RTC and IO_SLOT with 5802 and keep the deep sleep into the 30uA ???

4

Using WB_IO2 as interrupt is always bad.

Our WisBlock Mapper shows the best combination is to use Slot C for the RAK12002:

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5

thanks @beegee …

so RAK4631 + RAK19007 + RAK12002 in SLOT_C with pin4 as interrupt should get me in the same 30uA into deep sleep ?

then adding the RAK5802 into IO_SLOT and being controlled with WB_I02 should also let me use it with almost the same deep sleep current ?

6

Th Sensor Slots are identical beside of the used GPIO’s.
So if you see 30uA in Slot A, it will be the same in Slot C.

Regarding RAK5802 you will most likely see a higher current, how much, I can’t say without setting up such a system.

7

@beegee

  1. SLOT_C for RAK12002 with minimal code changes worked now and achieved low current (same as SLOT_A). Awesome!

  2. WB_I02 as IO_SLOT switch (ON/OFF) for the RAK5802 worked as expected, but as you recommended, UART stop = serialX.end() helped a lot

  3. disable pins later on the RX and TX pins of the serial, also the WB_I02 pins and all the LoRa pins did the trick.

RAK4631 + RAK19007 + RAK12002 + RAK5802 is doing ~30uA at deep sleep (with trickle charge of the RTC working fine and waking up the board at expected intervals)

PS: the WisBlock Mapper does not work with open source apps like Libre Office and Open Office