What is the meaning of "application processing" ?

RE: What is the meaning of "application processing" ?

endnode — Mon, 20 Nov 2017 21:02:11 GMT

Download and open "s132_nrf52_5.0.0.zip" with S130 V5.0.0 Soft Device delivery pack. Open "s132_nrf52_5.0.0_migration-document.pdf". Search for "BLE bandwidth configuration" or simply go to page 8. Read.

RE: What is the meaning of "application processing" ?

purgoufr — Mon, 20 Nov 2017 20:09:42 GMT

Ok. I understand the part about app processing. Thanks for this topic. But I still do not know how to change the number of packets to be received in each connection interval and how to determine it.Could you elaborate on this, please?

RE: What is the meaning of "application processing" ?

endnode — Mon, 20 Nov 2017 19:48:59 GMT

If you have questions to a blog post then post it under it in the discussion. If it is just dummy experiment like this you can easily place loops full of some dummy instructions (like NOP) and simulate MCU processing by the app. Because nRF5x chps have fixed frequency of ARM Cortex-M core it's quite easy to simulate certain occupation time. Indeed it's more difficult to solve opposite problem: measure processing time of real application code. But that's what I discussed above. If the simulation is the only problem then it's easy and solved I guess.

RE: What is the meaning of "application processing" ?

purgoufr — Mon, 20 Nov 2017 19:45:51 GMT

Also, he shared in the other experiment ;

S110 peripheral connection (example 3): Connection interval: 1 second Slave latency: 0 RX payload bytes in each packet: 0 bytes TX payload bytes in each packet: 20 bytes Number of packets to send in each connection interval: 1 packet Number of packets to receive in each connection interval: 1 packet Master clock 32kHz accuracy: 50ppm Slave clock 32kHz accuracy: 20ppm TX power: 0dBm application processing: 0% DCDC operation excluded Current consumption nRF51: 17.5uA

S110 peripheral connection (example 4): . . Number of packets to send in each connection interval: 4 packet Number of packets to receive in each connection interval: 1 packet . . Current consumption nRF51: 42.2uA I'm trying to figure out how he did it. (2/2)

RE: What is the meaning of "application processing" ?

purgoufr — Mon, 20 Nov 2017 19:44:18 GMT

The purpose is quite simple. I want to implement experimental work done on this blog I can change tx power, advertise interval and payload data bytes. But I'm trying to figure out how the guy who shared the experiment changed "application processing". I'll show you a piece of experiment;

Advertising 2: TX power: +4dBm adv interval: 1200ms payload: 10 bytes application processing: 2ms each adv interval. Average current consumption: 33,4 uA

Advertising 3: TX power: +4dBm adv interval: 1200ms payload: 10 bytes application processing: 0ms each adv interval. Average current consumption: 25,7 uA

I'm trying to figure out how he did it.

(1/2)

RE: What is the meaning of "application processing" ?

endnode — Mon, 20 Nov 2017 18:26:33 GMT

There are dozens of examples, it's just question what exactly you want to test. So far you are pretty vague. Power consumption measurements are not discipline which you would get from 200-letter answer on internet forum. You wither are trained in that or not. You can get some introduction when you read Nordic blog posts about how to use Power Profiler Kit (PPK) which might be the easiest way how to measure power profile of some FW on nRF5x chip (with nRF5x DK board).

(2/2)

RE: What is the meaning of "application processing" ?

endnode — Mon, 20 Nov 2017 18:23:18 GMT

How to measure application processing time for your particular FW? That's not obvious, you can try to measure it indirectly by things like power consumption curve or you can try to use some profiler like SEGGER SystemView. In every case it's not so obvious, straight forward and easy as you would probably like.
Your second question isn't very clear, how you can change capabilities of your BLE app on top of Nordic BLE stack aka Soft Device on some of their chips is explained in throughput configuration of each connection link during SD initialization/enabling. Read migration guide attached to your Soft Device, Soft Device specification on Infocenter and various Q&S on this forum. But it's basically in every BLE example in nRF5 SDK.

(1/2)

RE: What is the meaning of "application processing" ?

purgoufr — Mon, 20 Nov 2017 18:14:06 GMT

First of all thanks for your informations

How can I get "application processing" values in the blog. More specifically, how to measure "application processing"?
How can I change number of packets ?
Is there any example I can test as code? How does a friend who shares in the blog measure power consumption by changing these values?

RE: What is the meaning of "application processing" ?

endnode — Sun, 19 Nov 2017 19:48:31 GMT

Application processing is the when ARM Coretx-M MCU executes code of your application FW. In other words what you compile into binary and is processed at given interrupt or other trigger.

Number of packets is linked to mechanism how BLE Link Layer works. If you understand what Connection interval is and that normally (unless packet is lost or one of the sides uses Slave/Master Latency) two PDUs are exchanged (one Master -> Slave and one Slave -> Master) then it should be easy to understand that if both sides are able to execute more than one of such PDU-pair. If any of sides have more then one packet ready before connection event is scheduled and the opposite side reflects on MD bit in PDU header (More Data) then another PDU pair is exchanged until there are no more data o one of the sides have limit within the interval (these are stack and configuration specific).