Help Please !!! Remote Pushbutton starting/stopping SD card Logger shield

Hi Guys,

I have been toiling away at this project (sketches attached) and now its time to “ask an Expert” !!

I have written code for TX & RX utilising 2 x NRF24L01. All functioning. :slight_smile: :slight_smile: :slight_smile:

The Transmitter (UNO + NRF24L01 + Data Logger Shield) monitors 3 x analog inputs, transmits CSV & logs CSV file to SD card, constantly.

The receiver (Nano + NRF24L01) receives CSV file, constantly.

Almost perfect !

Would some-one (“Arduino Guru”) be able to advise of the required modifications to sketch to enable a “Latching Pushbutton”, located at Receiver (Slave) to “Start & Stop” recording of data on SD Card only. Transmission of Data to Receiver to continue “at all times” (only start & stop SD card recording).

I would greatly appreciate any recommendations/assistance offered.

Thanks in advance :slight_smile: :slight_smile: :slight_smile:

Marty

SADI_TX.ino (4.37 KB)

SADI_RX.ino (1.68 KB)

So at the moment, the data transmission is effectively in one direction. That is a transmitter unit collects data, stores it and also transmits it to a receiver unit. Now you want to send a signal from the "receiver" unit which controls something (data logging) on the transmitter unit. Is that it ?

Maybe the easiest way is for the receiver to return an "ack payload" to the transmitter each time it receives something. In that "ack payload" you encode the current required state of the data logging unit and handle it accordingly on the transmitter unit side.

Here is an example: https://shantamraj.wordpress.com/2014/07/19/exploring-the-auto-ack-feature-of-the-transceiver/

This Simple nRF24L01+ Tutorial may help. The second example uses the ackPayload feature.

It generally does not matter whether the principal data is sent as the message or as the ackPayload. In other words either Arduino can be the "master" as far as the wireless data is concerned.

...R