XBEE SLEEP_RQ and CTS signals on Stalker V3.1

I’m trying to create a low power data acquisition node using the Stalker V3.1 and Zigbee Pro Radio Modules. Everything works fine until I start putting in long delays. I believe my end node is doing it’s cyclical sleep process. If I send data to the module while it is asleep, of course there is no response.

I found a very useful book, Building Wireless Sensor Networks Using Arduino, by Matthijs Kooijman. He has examples using pin request sleep and CTS, that look like they would work. I know that I also can completely power down the XBEE using pin 9. That would probably be even lower power, but it seems like I still want access to CTS to know when the XBee is ready to receive data, after I power it back up.

So now I finally get to my question. Is there an easy way to access CTS? Or do I need to add a jumper from the XBee socket to a free digital pin?

Am I way off base, and is there another approach I haven’t tried? I think there is a workaround where I change the firmware from end node to router, so it doesn’t sleep, then use a long delay before I access the module. I’m hoping to find something a little less “hacky” than that.



Hi Todd

According to documents, If you enable hardware flow control (D7 command), the CTS pin asserts (low) when the device wakes.

There are two figures. Figure 1 shows where the CTS port is, and figure 2 shows the schematic of Stalker. You can see it’s not connected to ATmega328P MCU. You need a jumper.

figure 1

figure 2

If you have any other questions, please give feedback to us.

Thanks sincerely,