Is there any formula for current measurement for nRF51 dk?

[bikash]

I am using a nRF51822(pca10028) for current measurement. I had set up the devices as told in user guide. I am using SDK 11.0, softdevice s130 and default ble_app_pwr_profiling app from examples for current measurement. What are the measurements that I should expect from my set up?Any formula for current measurement with this or other apps to calculate current consumption?

[ToTo]

Hi

I didn't test this "le_app_pwr_profiling " frankly, but as i know it's testing mode OFF and SLEEP LOW POWER ADV and connection events.. Expected values you can calculate them from nordic specification and also using BLE event profiles presented by Nordic. This thread may help you. concerning mode OFF its around 0.6 uA as its written in the specification. These posts (1 ,2 and 3) also may help i recommend them for you

I hope that helps

[bikash]

I tried measuring with all the instructions given. I measured ~4 mA for advertising event. I don't know if I am wrong at some point or I missed something. :(

[ToTo]

What do you use for measuring ? (you should use an oscilloscope and get the profile like here ) I think the 4mA you get is the average, because the ampere-meter gives the average current. Listen : go to the this tutorial it's important. read how to measure the current using the oscilloscope

[bikash]

Thank you for your all inputs @ToTo. I followed all that tutorial and did accordingly. I got current consumption for single advertising event ~4 mA and for single connection event ~2.5 mA using oscilloscope. Now I have another question: is there any way to calculate current consumption theoritically (meaning calculating using values/parameters we used in code like interval,tx power,rx power, slave latency,rx payload, tx payload, clock accuracy ) so that we can compare our practical result with theoritical result?

[ToTo]

Sorry, i clicked on convert to a answer by accident.

Listen, i'm doing the same thing , i did an theorical and practical calculation of my app and i used the stuff i showed you : the BLE profiles (i used only the ADV profile and Connection peripheral event profile as they are in the nordic discription because in my app i use only those ones) and i got a very logic results with difference of about 0.5 mA between theorical and pratical (that's logic because i work on worst case when using theorical values).

All i did, is refering to the link i mentioned before in my comments. just do some effort you will find all there..

When you measured with the oscilloscope (the ADv events for example), did you find a profile like mentionned in Nordic description ? ( minimize the time division with push-zoom in the oscilloscope )

how did you find 4mA? do you mean you get it directly by reading form oscilloscope ? if that's what you mean so i don't think it's right. You have to zoom as i told you, and find the different stages discribed by nordic , and calculate each stage current then calculate the current average ( integral calculations )