Star Network 4 peripherals 1 central - best SoC for this? 433 MHZ? 2,4 GHZ?

[muhkuhns]

Hello everyone!

Just have a look at this beautiful drawing. (Red: what has to be done. Black: Can it be done this way?)

I only have some rudimental experiences in microcontroller programming and none with bluetooth stuff.

For a part of my study I will need to wireless get data from 4 sensors.

After some research I came to the conclusion that the best way would be to use 4 of those chips from here: www.aliexpress.com/.../130096_1358212667.html

My sensors can be connected via I2C oder SPI. So that shouldn't be a problem. I already found the SDK for the nRF51822 and it looks promising so far.

What else will I need... Well the 4 modules have to be progammed/debugged somehow and send the data to some shared point... What is the cheapest+easiest way for this? The nRF51 Development Kit?

Sum up: 4 physically separated sensors who can communicate over I2C or SPI have to send wireless Data every (few) second(s) or so to a central data log point (another µC (nRF51-DK?) and/or Computer).

As far as my understanding goes, this should be possible with the PTRs using S110 Soft Device (peripheral) and the nrf51-dk using S120 (central)?

I found a guide nAN-36 Template Application: developer.nordicsemi.com/.../a00076.html ) which will hopefully enlightens me to code the peripheral side of the problem.

Is there such a guide/thing for the central part?

Most important part is to let the 4 PTRs transmit their sensor readings to the central unit. (Or the other way around if that's the way BLE is working.. still reading trough the nAN-36.pdf)

The peripherals will be in a fast circular motion (~120rounds per second).

Kind Regards

[cocoa]

Hi, if you don't need to be BLE compatible, have a look to Nordic Gazelle propietary protocol or ANT.

-c

[muhkuhns]

Thanks for pointing it out :) Looks promising. Guess I will give developer.nordicsemi.com/.../a00108.html a go when my nRF51-DK arrives. Will it still work with nRF Master Control Panel on Android? I'm a little confused with the "pipes" and the pairing.. can I pair 4 devices without a problem?

[Petter Myhre]

I don't have experience with the PTR5528, but it should be fine.

The nRF51-DK is a good choice if you need a central device and a programmer/debugger.

Your understanding is correct regarding the peripheral and central roles of the devices.

Unfortunately, we only have such a guide for the peripheral side, but we have examples for the central side and some information on Devzone. The be honest, the nAN-36 is a bit outdated, but the you can find the source code compatible with the latest SDK (8.0) here.

How is the central unit making use of the sensor data? Displays it or something like that? Does it need to transfer the sensor data to a smart phone for example?

[muhkuhns]

Thanks for your answer!

For measurement series I need to export the data to my Laptop.That shouldn't be a problem with the nRF51-DK connected to the Laptop I guess ;-) From this data I will then create an algorithm which shall later run on the nRF51-DK. For the presentation it could be useful if the central could output the data of the algorithm on a display.. but I think the Laptop will do fine for that too. (But can you recommend any displays for the nRF51-DK? with a working library maybe..)

In the end the data needs to either get transmitted via Bluetooth to an onboard car-computer but most likely via CAN-Bus. ( There just needs to be the possibility and some thoughts, I don't have to accomplish this by all means )

It need to send some small commands from the central to the peripherals as well.

[Petter Myhre]

It shouldn't be a problem to export the data to your laptop over UART, or to send commands from the central to the peripherals.