NRF24L01 STANDALONE

NRF24L01 STANDALONE

is anyway to use it standalone ... or need something with very little power consumption.
Need to do witless mark witch send some data every 30sec and sleep all other time.

Wireless or witless?

You will need a seperate processor of some sort to assemble and send / receive and decode the data.

The radio link doesn't do any of this

Allan

Solar powered wireless remote sensor (NRF24L01) setup decribed here https://www.gammon.com.au/forum/?id=12821

need something compact that I can but it into my wallet ...

Sounds like a carefully thought out project!
What important data will be sent from your wallet?

This Simple nRF24L01+ Tutorial may be of interest.

As well as the need for a microprocessor you will also need something to generate data to send or act on data that is received.

I am making a small unit to fit in a model train using an nRF24 and an Attiny 1634. It looks more or less like this. For the model train there will also be a Pololu DRV8833 h-bridge to control the motor.

Note that an essential 0.1µF capacitor is missing from the Attiny Vcc and GND and the photo does not show a 10µF capacitor across the nRF24 Vcc and GND which is under the nRF24

...R

jremington:
Sounds like a carefully thought out project!
What important data will be sent from your wallet?

Will send key which need to be generated with some rule each one have to be different but main unit have to recognize it ... Its confirmation for car start engine.

RipperR:
Will send key which need to be generated with some rule each one have to be different but main unit have to recognize it ... Its confirmation for car start engine.

How about taking a few minutes to write a comprehensive description of the project you want help with?

...R

-Arduino DUE placed into car.
-cut starter wire from key ant relay placed here.
-2 systems will build in car
First standard rFID card which will be read card and lock relay if its right one
second is wireless card and little wireless transmitter with close range radio 2-5m it has to send key to car receiver connected to Arduino key has to be some sort of encoding and each time has to be different code to protect for copy it (car receiver has to remember at least 20 keys received to protect for receiving it again) if receiver get key it send agreed message for wireless key to say it key received and it has to change it other one.

car receiver will be enabled when car key placed in to lock there pin will be displaying with 12v signal that its enabled all other time it has to be turned off...

  • second side of that system its ALARM module with gps gsm bluetooth (probably I will use to third way of authentication like my phone connects to Bluetooth like a key and so on but it will be different story ...
  • need some backup power from 18650 with charger ...

I've already ordered Arduino DUE, SIM808(sms sending and using internet for send log files, gps for tracking), RC522 + 13.56 MHz keys, 2 OMRON solid relay, 2 standart relays, 2x analog shock sensors (for two stages of shock little and critical for siren run), DS3231 clock (for some watchdogs and LOGing), GY-471 (Volt Amps meter if volage of battery goes below 12.2V should send SMS with alarm), 4x NRF24L01 + adapter + 1 long range with antenna, mb102 Power supply, ATmega328 PRO MINI for extra work latter and breadboard for testing and 128X64 OLED LCD 0.96 "I2C IIC SPI for something latter on ... I'm looking for good I2C temperature sensor, and good accelerometer.

It is my first experience with Arduino but I have got programming experience at php, C#, MySQL , MsSQL so I think I can do it with your help.

I can't see the need for a DUE. An Attiny would probably be sufficient.

Your description could do with a lot of editing to make it clearer.

Is this a reasonable description of what you are trying to achieve?

  • You want to have an Arduino in the car that can activate a relay to close the wire from the key-switch that activates the starter motor (presumably to make it impossible to start the car with the key on its own).
  • The Arduino will have a wireless receiver and when it gets a valid message from another Arduino with a wireless transmitter it will cause the relay to close - and stay closed (presumably).
  • When the Arduino has received a valid signal and activated the relay the key-switch will be able to start the engine.

If I have it wrong please correct it.

As with any project take its development in small steps.

  • Figure out what is needed to make an Arduino operate a relay
  • Figure out how to send messages using wireless.
  • Figure out whatever security coding system you want to use.
  • etc

When you know how to do each piece on its own you can start joining them together

I presume there is NO possibility of your system causing the engine to stop - if there is, then you should seek the approval of your motor insurer before proceeding with the project.

...R
Planning and Implementing a Program

You are right ... I've ordered relay that is closed by default ... so when Arduino starts it will open relay to disconnect wire from key to car brain to disallow it start without key validation... so if something went wrong I just have to power off Arduino to let it work as normal ... (all relays that I will use when cut wires will be connected to normal close port to protect myself from issues and it will by hided to place that need much time to reach and second way to protect from some strange issues will be some fuse at standard car fuse desk what will looks like lot of other fuses. (but if I want to use backup power supply need to use one more fuse to disable battery so it two fuse desks at car so one fuse will be inside car second near engine to protect from easy disable it and make more time to find the solution ...

About key (card) working ... When car/key validate successfully system stopped requesting key till car's key is removed .... (best way is always request key with some interval for example every 5 minutes (if car started with wireless key) so it will work like. IF car is hijacked key stolen but they don't have wireless key that is in my wallet (for example) so after 5 minutes engine will stopped ...

One more thing that I need to stabilize somehow car power that I will use to power Arduino it varies from 12.0V to 14,6V need to make it stable 12.0V with some power filter from interference or something that can damage Arduino and other staff. Second thing need to make some Backup power supply that can power Arduino without car battery and charge it when engine is started (I want to protect car battery from drained of Arduino I will use some lipo power source to allow it work 7 days without car charge it)

I'm on way to structurize evens and action at that project but it written at my native language and it will be useless to community.

Sorry for that I can clearly explain what I'm want to do ... =( Maybe some other things I will be need later ...

The fact that a relay is closed by default and can be opened by an Arduino is no guarantee against the possibility of the relay being triggered at the wrong time. Don't interfere with any circuit where spurious (or deliberate) activity by your equipment might cause the engine to stop.

...R

Maybe some capacitors can protect from that suddenly events ...

RipperR:
Maybe some capacitors can protect from that suddenly events ...

NOTHING can protect you 100% from the unexpected - and certainly not a microprocessor. Saying "sorry my code had a bug" or "sorry, I had too many or too few capacitors" is not an acceptable answer if an engine failure results in death or injury.

I see nothing wrong with a circuit that prevents the starter motor from being operated. But such a circuit cannot cause the engine to stop because the starter motor plays no further part once the engine is running.

...R

So my logic can alive at hardware ?
I still need advice about remote key how to make it power efficient to running from little CR2032 at least month ... but more is better

Have a look at Nick Gammon's power saving tutorial

...R