[Energia Library] Nordic nRF24L01+ library

spirilis · March 15, 2013

Small addition- A private state variable 'readpending' has been implemented that is set in _maintenanceHook() and not cleared until read(). This allows persistent testing of .available(1) for more freedom in your coding.

An example of a scenario this would fix:

while ( (millis()-saved_time) < 5000 && !nrf.available(1) )  // Two different tests
  ;
// Ambiguity here--Which condition broke the while() loop?

// This will always fail because if nrf.available(1) succeeded up above, the internal
// _maintenanceHook() call will have cleared the IRQ and nrf.available(1) checks that.
// Can use .available(0) instead.
if (nrf.available(1)) {
  .... read packet and handle ...
}

Now that scenario could be handled by just testing if the millis() condition was the one that broke it, but what if both conditions occurred simultaneously? It's tricky. Then the user would have to remember to use .available(0) in the 2nd instance instead of .available(1). Adding extra SPI I/O imo.

With this "readpending" variable added, the 2nd nrf.available(1) will succeed since _maintenanceHook() from the "!nrf.available(1)" condition in the while() loop will have set readpending=1 once it discovered an IRQ was raised and went to clear it. Further executions of nrf.available(1) will continue to report TRUE until nrf.read() is finally executed.

This does not affect the behavior of nrf.available(0) at all. nrf.available(0) goes out over SPI and asks the transceiver if its RX buffers are empty to determine whether there is data pending or not. It's more thorough.

Note that if an error packet (size=0 or >32) was found during the _maintenanceHook() execution, readpending is forcibly set to 0 (because a FLUSH_RX command is required to clear the error packet, throwing out everything in the RX queues).

OzGrant · April 7, 2013

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spirilis · April 7, 2013

Weird. What else is attached to the receiver launchpad?

OzGrant · April 7, 2013

G

OzGrant · April 7, 2013

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spirilis · April 7, 2013

The main thing I'd offer is that 2.4GHz is a warzone of noise, and some channels are likely to be noisier than others so you may find some nodes don't work so well. I'd recommend using the 5-byte RF addresses and stick with one channel--my example channel scanner (in the library) could help you find one that's very quiet.

Also with long distances, I recommend using 250Kbps data rate as it's substantially more reliable over distance. Only downside is under the hood it won't perform auto-ACK.

OzGrant · April 7, 2013

Yup, RF address sounds the best. Tks

huskerfreak · April 13, 2013

I a super green noob and i can do a lot of the basics but I am stuck on how to the following. I want to have a wireless motion trigger the following code is what I use for taking pics with a wired motion trigger but I am not sure how or what would be the next step to making it wireless. Any help would be appreciated I have a set of the

nRF24L01 to use for this. I ultimately want use the wireless msp430s but I thought I would try first with this.

/**********************
 * Motion Activated Camera
 * Dan Bridges 2009
 * 
 * For schematics and more documentation see:
 * http://www.dayofthenewdan.com/projects/motion-camera
 **********************/


boolean focus = false;

int shutterPin = 2;
int focusPin = 3;
int PIRPin = 4;

int shutterPressDelay = 200;
int focusPressDelay = 200;
int interPictureDelay = 500;


void setup(){
  pinMode(shutterPin, OUTPUT);
  pinMode(focusPin, OUTPUT);
}

void loop(){
  if (digitalRead(PIRPin)) {
    takePicture();
    delay(interPictureDelay);
  }
}

void takePicture() {
  //If you want the camera to focus first set
  //the focus variable to true.
  if (focus) {
    digitalWrite(focusPin, HIGH);
    delay(focusPressDelay);
    digitalWrite(focusPin, LOW);
    delay(250);
  }
  digitalWrite(shutterPin, HIGH);
  delay(shutterPressDelay);
  digitalWrite(shutterPin, LOW);
}

neborkia · April 30, 2013

Ok, hello again...

So after rereading this topic, I patched Energia and got the correct resulst in the TX, RX and scan examples

[...]

So this is really related to the Energia problem, I have to improve my github skills...

I will go on and try receive/transmit examples on 2 launchpad soon.

Sorry for disturbing you with this.

Hi!

I'm having the same issues with the TX and RX examples... what i've to do to patch Energia?

Thank you,

V.

EDIT: After few hours of sleep i've successfully patched Energia and now the TX/RX demo is working! Thanks again!

Pradeepa · May 5, 2013

good day guys,

I'm totally new to Energia. This is my requirement.

I have a stellaris launchpad LM4F120 and a MSP430 launchpad for 2553. I need to establish a simple communication link between these two using NRF24L01 transceivers.

I downloaded energia. Then I downloaded the files "spirilis" linked in this post. I copied Enrf24.h, Enrf24.cpp and nRF24L01.h to Enrf24_RXdemo folder. Then I opened the .ino file through energia. But when I verify it through energia I got the following error messages. Please help me through.

Enrf24.cpp: In member function 'void Enrf24::begin(uint32_t, uint8_t)':

Enrf24.cpp:65:27: error: 'BIT2' was not declared in this scope

Enrf24.cpp: In member function 'void Enrf24::_maintenanceHook()':

Enrf24.cpp:239:41: error: 'BIT1' was not declared in this scope

Enrf24.cpp: In member function 'boolean Enrf24::available(boolean)':

Enrf24.cpp:277:39: error: 'BIT0' was not declared in this scope

Enrf24.cpp: In member function 'size_t Enrf24::read(void*, uint8_t)':

Enrf24.cpp:293:37: error: 'BIT0' was not declared in this scope

Enrf24.cpp: In member function 'void Enrf24::flush()':

Enrf24.cpp:316:13: error: 'BIT5' was not declared in this scope

Enrf24.cpp:322:13: error: 'BIT6' was not declared in this scope

Enrf24.cpp:337:16: error: 'BIT1' was not declared in this scope

Enrf24.cpp:338:49: error: 'BIT3' was not declared in this scope

Enrf24.cpp:338:49: error: 'BIT2' was not declared in this scope

Enrf24.cpp:341:13: error: 'BIT0' was not declared in this scope

Enrf24.cpp:344:49: error: 'BIT3' was not declared in this scope

Enrf24.cpp:344:49: error: 'BIT2' was not declared in this scope

Enrf24.cpp:344:75: error: 'BIT1' was not declared in this scope

Enrf24.cpp: In member function 'uint8_t Enrf24::radioState()':

Enrf24.cpp:396:16: error: 'BIT1' was not declared in this scope

Enrf24.cpp:400:13: error: 'BIT0' was not declared in this scope

Enrf24.cpp:407:36: error: 'BIT4' was not declared in this scope

Enrf24.cpp: In member function 'void Enrf24::deepsleep()':

Enrf24.cpp:417:14: error: 'BIT1' was not declared in this scope

Enrf24.cpp:417:28: error: 'BIT0' was not declared in this scope

Enrf24.cpp:418:49: error: 'BIT3' was not declared in this scope

Enrf24.cpp:418:49: error: 'BIT2' was not declared in this scope

Enrf24.cpp: In member function 'void Enrf24::enableRX()':

Enrf24.cpp:428:47: error: 'BIT3' was not declared in this scope

Enrf24.cpp:428:47: error: 'BIT2' was not declared in this scope

Enrf24.cpp:428:73: error: 'BIT1' was not declared in this scope

Enrf24.cpp:428:87: error: 'BIT0' was not declared in this scope

Enrf24.cpp: In member function 'void Enrf24::disableRX()':

Enrf24.cpp:443:13: error: 'BIT1' was not declared in this scope

Enrf24.cpp:446:49: error: 'BIT3' was not declared in this scope

Enrf24.cpp:446:49: error: 'BIT2' was not declared in this scope

Enrf24.cpp:448:49: error: 'BIT3' was not declared in this scope

Enrf24.cpp:448:49: error: 'BIT2' was not declared in this scope

Enrf24.cpp: In member function 'void Enrf24::setCRC(boolean, boolean)':

Enrf24.cpp:509:16: error: 'BIT3' was not declared in this scope

Enrf24.cpp:511:16: error: 'BIT2' was not declared in this scope

Thank you in advance.

EDIT::: Sorry for the dumb question. I figured it out.

Edited May 5, 2013 by Pradeepa

Pradeepa · May 6, 2013

How to port this over to Stellaris Launchpad?

dzsombor96 · May 6, 2013

Hi. Just red the whole 3 pages but it is not really clear how to patch energia... Can someone explain it as simply as it can be? Another question: What is the range approximetly on the modules (without the amp) on 1Mbps and 250Kbps?

Pradeepa · May 7, 2013

Good day,

I want to connect my Stellaris launchpad and the MSP430 2553 using NRF24L01 transceivers. I found following energia libraries,

For MSP430

http://forum.43oh.co...f24l01-library/

For Stelaris launchpad

http://forum.stellar...f24l01-library/

After that I connected the pins of the modules like below,

MSP430

CE >> P2.0

CSN >> P2.1

SCK >> P1.5

MOSI >> P1.7

MISO >> P1.6

Stellaris launchpad

CE >> PA6

CSN >> PA7

SCK >> PB4

MOSI >> PB7

MISO >> PB6

Then i used putty to check whether the transmission is happening. But I think it is not.

MSP430 serial interface gives my this result,

Enrf24 radio transceiver status: Receive Mode

Received packet: