Low power operation

Seems asserting high SLEEP_REQUEST pin doesn’t sleep the module if SPI lines are enabled.

It does work when using UART only, but not with SPI ( verified by measuring current draw with mm device)

is this the normal behaviour?

Documentation says one can drive sleep and transmission with SSEL only if SLEEP_REQUEST disabled, but I actually need to have separate line to sleep the module.

Which XBee module and firmware version are you working with?

XBP9B-DMST-002 revB
firmware: 806A (200 kbps)

there are two firmware updates, but release notes don’t say anything about it.

Try upgrading to version 8071.

Try deasserting the slave select pin.

I am experiencing the same problem on XBee 868LP 80K with firmware 8074.

I am using SPI, and have tried to use sleep request AND slave select (by disabling sleep request) as sleep drivers. Indeed this seems to work only for UART and not for SPI. Once SPI is started, the current draw jumps up about 20mA and doesn’t come down again even when the sleep pin is driven high.

I also notice that when the UART pins are disabled from the get-go, the current draw has this 20mA offset from startup, presumably since it has immediately started up SPI because of the lack of UART.

Is there anything I can try to resolve this?