what happens to PWM when xmitter goes to sleep?

With suitable config I think I should be able to have an analog input on AD0 on a “transmitter” module presented as a PWM output on PWM0 on a “receiver” module.

In my application the source analog signal changes very slowly, I only need a sample every 60 seconds. To save power I would like to put the xmitter to sleep (or power off) in between samples.

What happens to the PWM output at the receiver if the xmitter is asleep/power off ? Ideally the PWM signal would continue until the next sample at which time it might change. Is this possible?

Good question.
I believe that the digital outputs hold their drive level when the RF module is sleeping so the PWM may also continue.
It wouldn’t be hard to find out by trying it.

> It wouldn’t be hard to find out by trying it.

I would … but I’m in “design mode”, I havn’t ordered my xbees yet, I’m still trying to figure out what they can do!

In the normal way of things, you’ll send a command to an XBee to set a particular output value and it’ll then maintain that value until it’s told something else. So if the transmitter goes to sleep, the output voltage will stay the same.

With digital outputs there’s an extra feature where you can set a default value and a timeout. If you don’t change or confirm the actual value within the timeout, it’ll revert to the default.

You’ve posted this in the 802.15.4 forum: I don’t guarantee my answer for other varieties of Xbee. But then, I don’t guarantee my answers anyway… :slight_smile: