ATmega128RFA1 Minimum awake/transmission time

[gkopins]

Hello,
I am posting this question on behalf of my customer...

In the tests that we did, we found that a minimum time of 20ms was required for transmission/reception. Is there a way to reduce time further down?

We are trying out the program by keeping the board in SLEEP state for a few seconds and then in ON state to check if there is any incoming signal from another node so we can conserve the battery. We need to reduce the ON time to a very short window and still be able to receive at least 5 packets. We are planning to have the Node in SLEEP mode for 1s-2s. And we would like to know if there is a way by which we can have the node ON state in the 500us-1000us and still be able to receive packets without loss.

Is the 20ms time a hardware limitation or is it because of the initialization procedures the function needs to undergo?

Thanks,
Greg

[Jheath]

SNAP has been tested to as fast as ~5ms in receiving an input on a pin, transmitting a message to another node, and actuating a pin transition the destination node. This was done using un-acknowledged mcastRpcs.

One way to reduce the transmit time is to disable the collision avoidance mechanism (see configuration parameters in Portal or NV 18). This places a random delay before transmitting messages. The delay aids in avoiding collisions (hence the name) in situations where a number of nodes might attempt to respond to message at the same time.

[gre7g]

By tweaking the parameters, you probably could achieve an on-time shorter than 20ms, but I would not expect to get into the microsecond range.

If the customer needs that, then they should contact the custom solutions group. The ATmega128RFA1 has some really cool high-speed-ack features that could be leveraged, but there would be some NRE to do the research.