RAK3172 P2P RX enable time

Hi there. I’m using a RAK3172 in P2P mode. The RUI version of the module is 4.0.5.
I’ve noticed that when I raise the module RX with the command AT+PRECV=65533, the time taken to respond an ‘OK’ is 8ms or 21ms (not values in between). Why are these values fixed and why does it sometimes take longer?
My application needs to be as fast as possible, so these 13ms are crucial.

Thanks in advance.

Mati.

Welcome back to the forum @MatiasColly

If you use AT+PRECV=65533 you enable RX mode with TX possible.
You need to issue this command one time, it will stay in RX mode, when you send a packet with AT+PSEND, it will go back to RX mode after the packet was sent.

So you need to send AT+PRECV=65533 one time after power up or reset.

Why is the time difference of 13ms in the response a problem? It is most likely linked to the scheduler that is controlling tasks inside of RUI3.

Bernd, thank you for your reply.

I’m implementing a system where I send packets between devices every 150ms. As the product is battery powered, the power consumption needs to be as low as possible. So to save power I wanted to turn off the RX between packets but I’m facing this inconsistency where sometimes it turns off fast and sometimes it turns off slow. And this difference is causing me to lose some packets. So I was hoping to know if there is a reason for this 13ms delay and how to avoid having to wait for the longest time.

Thanks.

Hey Mati,

The fixed response times you’re seeing might be due to internal processing within the RAK3172 module. Factors like system load and signal noise can affect response times. To ensure the fastest response, you might need to optimize your application code and minimize external factors affecting the module.