Another processor with NRF52

[Raja]

I have created a program on Arduino which does audio/video output and takes input from accelerometer and camera module. I was able to move accelerometer code to NRF52 with @martinbl e.g.

On other posts it was mentioned with softdevice running we might get problem with audio output. Also i was not able to create any e.g. with audio/video on NF52.

Now i was thinking of having another chip like avr or arm processor which can take commands from NRF52 via rx/tx and run audio/video etc. By this Nrf52 will only be responsible for BLE connection and other chip for processing commands.

Am i completely wrong or is this right way? If i am right can you please recommend any chip which is used commonly with NRF52 and is rx/tx best way to communicate with primary nrf52 chip?

Thanks

[Raja]

Thanks @endnode your points are very valid. It is a great forum and nordic is doing good job also skilled people like you also contribute a lot and i respect it. I use to develop on Arduino at start then realised i need to properly develop using industry standard hardware and tools. So i moved to Nordic chips as i need BLE for what i need to develop. They have great forum here with tutorials. So in past 3 months i have learned a lot. Now i can comfortably develop BLE services talking to my custom made apps on iOS and android. I have learned how to integrate different hardware components. For some i am still finding ways like for touch screen display/audio out/microphone etc. Also i was able to use open source tools in my journey here. I have been developing software professionally for last 20 years and have moved a lot between different technologies like server side, web, desktop, databases, big data and mobile this was only possible as in software side companies like microsoft, oracle, google apple spend lot of time writing tutorials for new developers to there platform so i would request nordic to take same approach and carry on there amazing works by adding new tutorials every 2 weeks and keep there existing tutorials upto date.

[endnode]

Makes sense!

[MartinBL]

In addition to all the points @endnode has made I just want to point you towards some solutions and documentation. To do audio stuff you might be interested in the I2S feature of the nRF52. The I2S implements what we call EasyDMA that allows you to access internal Data RAM without CPU intervention. This in turn allows you to stream continuous data from RAM without worrying about the Softdevice. You can also use EasyDMA with the PDM to, to record audio, store it in RAM, and then stream it with I2S almost completely without CPU intervention (you will need software interrupts to update pointers to bufferes in RAM from time to time, but this can be done whenever the Softdivice isn't using the CPU).

Finally, here you can find some tables showing how much of the time the Softdevice uses the CPU in various scenarios: Bluetooth low energy processor usage patterns.

[Raja]

Thanks @martinbl i also used your EasyDMA e.g. for mpu-9250 they were brilliant. Do you have any e.g. for audio also using nRF52?

[MartinBL]

I'm glad you found them useful. Unfortunately this is all we have for audio: I2S example.