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Randy
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| Help using enhanced shockburst for the NRF24L01 |
 Posted: Mon Oct 06, 2008 8:32 am |
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I have working code for the NRF24L01 transceiver. Works great if I use the transceiver as is. Can anyone shed some light on how to use enhanced shockburst with the driver I have written. I tried enabling auto ACk and set the CRC but it doesn't seem to work.
Thanks
NRF24L01 DRIVER
| Code: |
/**************** Preprocessor Constants ***************************************/
#define CONFIG 0x20
#define EN_AA 0x21
#define EN_RXADDR 0x22
#define SETUP_AW 0x23
#define SETUP_RETR 0x24
#define RF_CH 0x25
#define RF_SETUP 0x26
#define STATUS 0x27
#define RX_ADDR_P0 0x2A
#define TX_ADDR 0x30
#define RX_PW_P0 0x31
#define FLUSH_TX 0xE1
#define FLUSH_RX 0xE2
#define TX_PAYLOAD 0xA0
#define RX_PAYLOAD 0x61
#define NO_OP 0xFF
#define ZERO 0x00
#define EOT 0x04
#define PAYLOAD_SIZE 0x20
#define start_transmit {output_high(rf_CE);delay_us(20);output_low(rf_CE);} //Pulse NRF24L01 CE pin for 20us
int1 rf_interrupt=false; // Declare interrupt flag default is false
static int16 rf_CE,rf_CSN; // Declare NRF24L01 SPI CE & CSN pins
/**************** Gets The Length Of A Data Packet *****************************/
unsigned int* length(unsigned int *data)
{
int *cnt; // Declare a pointer
for (cnt = data; *cnt != 0; cnt++); // Loop
return(cnt - data); // Return the length of the data
}
/**************** Write To NRF24L01 Configuration Register *********************/
void set_register(unsigned int command,unsigned int data)
{
output_low(rf_CSN); // Engage SPI chip select
spi_write(command); // Write to register
if(data!=NO_OP){spi_write(data);} // Write data to register
output_high(rf_CSN); // Dis-engage SPI chip select
delay_us(10);
}
/**************** Write To NRF24L01 Configuration Register *********************/
void set_register(unsigned int command,unsigned int* data)
{
int i,len;
len=length(data); // Get the length of the data
output_low(rf_CSN); // Engage SPI chip select
spi_write(command); // Write to register
for(i=0;i<len;i++){spi_write(data[i]);} // Write data to register
output_high(rf_CSN); // Dis-engage SPI chip select
delay_us(10);
}
/**************** Enables NRF24L01 Transmit/Receive Mode ***********************/
void transmit_mode(unsigned int1 enable)
{
output_low(rf_CE); // Disable receiver
set_register(STATUS,0x7E); // Clear all interrupts
if(enable)
{
set_register(FLUSH_TX,NO_OP); // Flush TX FIFO buffer
set_register(CONFIG,0x52); // Power up in select transmit mode
}
else
{
set_register(FLUSH_RX,NO_OP); // Flush RX FIFO buffer
set_register(CONFIG,0x33); // Power up in receive mode
output_high(rf_CE); // Enable receiver
delay_us(130); // Delay 130us
}
}
/**************** Transmits A Single Byte **************************************/
void rf_transmit(unsigned int data)
{
transmit_mode(true); // Enable transmit mode
output_low(rf_CSN); // Engage SPI chip select
spi_write(TX_PAYLOAD); // Select tx payload register
spi_write(data); // Write data to tx payload register
spi_write(EOT); // End of transmission
output_high(rf_CSN); // Dis-engage SPI chip select
start_transmit; // Start transmission
transmit_mode(false); // Enable receive mode
delay_ms(50); // Delay 50ms
}
/**************** Transmits A String Of Data ***********************************/
void rf_transmit(unsigned char *string)
{
int i,len=0;
len=length(string); // Get the length of the data to transmit
transmit_mode(true); // Enable transmit mode
output_low(rf_CSN); // Engage SPI chip select
spi_write(TX_PAYLOAD); // Select tx payload register
for(i=0;i<len;i++){spi_write(string[i]);} // Write data to tx payload register
spi_write(EOT); // End of transmission
output_high(rf_CSN); // Dis-engage SPI chip select
start_transmit; // Start transmission
transmit_mode(false); // Enable receive mode
delay_ms(50); // Delay 50ms
}
/**************** Receive RF Data **********************************************/
unsigned int* rf_receive()
{
int i;
static int rf_rx_buffer[PAYLOAD_SIZE]={0}; // Declare a receive buffer
rf_interrupt = false; // Clear interrupt flag
output_low(rf_CE); // Disable receiver
output_low(rf_CSN); // Engage SPI chip select
spi_write(RX_PAYLOAD); // Initialize RX payload register
for(i=0;i<=PAYLOAD_SIZE;i++)
{
rf_rx_buffer[i]=spi_read(RX_PAYLOAD); // Copy data from NRF24L01 to buffer
if(rf_rx_buffer[i]==EOT){rf_rx_buffer[i]=ZERO;break;} // Stop when EOT found
}
output_high(rf_CSN); // Dis-engage SPI chip select
transmit_mode(false); // Enable receive mode
return rf_rx_buffer; // Return received payload
}
/**************** Checks The Status Register ***********************************/
void check_interrupt()
{
int i,reg;
output_low(rf_CSN); // Engage SPI chip select
for(i=0;i<5;i++){reg=spi_read(0x07)&0xFF;} // Read 5 chars of data from NRF24L01 RX register
output_high(rf_CSN); // Dis-engage SPI chip select
if(reg>>6){rf_interrupt = true;} // If RX_DR set,set data ready flag
else{set_register(STATUS,0x7E);} // Clear all interrupts
}
/**************** Initialize NRF24L01 Chip *************************************/
void setup_rf(unsigned int16 CE,unsigned int16 CSN,unsigned int* address,unsigned int CH,unsigned boolean Mbps,unsigned int dBm)
{
rf_CE=CE; // Define CE pin
rf_CSN=CSN; // Define CSN pin
setup_spi(SPI_MASTER|SPI_L_TO_H|SPI_XMIT_L_TO_H|SPI_CLK_DIV_64); // Setup hardware spi
output_low(rf_CE); // Disable receiver
set_register(CONFIG,0x31); // Power down chip
set_register(RF_CH,CH); // Set RF channel
set_register(RF_SETUP,(Mbps<<3)|(dBm<<1)|0x01); // Set data rate and power level
set_register(SETUP_AW,0x03); // Set address width to 5 bytes
set_register(EN_AA,0x00); // Disable auto acknowledgement
set_register(SETUP_RETR,0x05); // Set auto retransmission for 5 tries
set_register(TX_ADDR,address); // Set transmit address
set_register(RX_ADDR_P0,address); // Set receive address
set_register(EN_RXADDR,0x01); // Enable RX address 0
set_register(RX_PW_P0,PAYLOAD_SIZE); // Set RX payload to receive up to 32 characters
transmit_mode(false); // Enable receive mode
}
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IMPLEMENTING THE DRIVER
| Code: |
#include <16F873.h>
#device PASS_STRINGS=IN_RAM
#FUSES NOWDT, XT, NOPUT, NOPROTECT, NOBROWNOUT, NOLVP, NOCPD, NOWRT, NODEBUG
#use delay(clock=4M)
#use rs232(baud=9600, parity=N ,xmit=PIN_C6,rcv=PIN_C7, bits=8)
#include <nrf24L01.c>
#define BUFFER_SIZE 32
/************************ Global Variables *************************************/
const int address[5]={0xE7,0xE7,0xE7,0xE7,0xE7}; // Declare address array
static int packet[BUFFER_SIZE];
int1 data=false;
/**************** Process Data Packet ******************************************/
void process_packet(unsigned int* data)
{
printf("DATA IN: %s\r",data);
}
/**************** Process Data Packet ******************************************/
#INT_RDA
void rs232()
{
gets(packet);
data=true;
}
/**************** Interrupt Request ********************************************/
#int_ext
void interrupt_request()
{
check_interrupt();
}
/************************ Main Loop ********************************************/
void main()
{
setup_rf(PIN_C1,PIN_C2,address,2,0,3); // Initialize RF transceiver
enable_interrupts(INT_RDA);
ext_int_edge(H_TO_L); // Enable interrupt on high to low transition
enable_interrupts(INT_EXT); // Enable PORTB.0 interrupt
enable_interrupts(GLOBAL); // Enable global interrupts
while(true) // Loop forever
{
if(rf_interrupt){process_packet(rf_receive());} // Check to see if data has been received, if so process data
if(data)
{
data=false;
rf_transmit(packet);
}
}
}
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dan king
Joined: 22 Sep 2003
Posts: 119
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| Posted: Tue Oct 07, 2008 7:07 am |
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check out this link, they have tutorials for using the NRF24L01 transceiver and one of the tutorials sets up and uses the auto ack. I just started working with this a couple days ago and everything works pretty well. I even enabled the auto ack after getting the demo link working and have been impressed with the retransmit feature.
The sample code was easily ported to CCS C.
http://www.diyembedded.com/
Dan |
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Laalaa
Guest
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| Posted: Tue Jul 28, 2009 5:25 am |
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| Does anybody manage to work the Enhanced Shockburst? |
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loggin
Joined: 23 Sep 2010
Posts: 10
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| Posted: Thu May 26, 2011 6:21 am |
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Hello to all!
I'm to use the same topic. I've got a question about sending and receiving. I used the code above and I marked that if I send for example 5 bytes from Tx to Rx there is a kind of problem - 0th byte is the same at the receiver but 1st, 2nd and etc. are not the same, i.e. there's an error. More detailed - in receiving mode for example 2nd received byte from 10 receivings, 6-7 times is the same byte which I send by TX side (no error) but other times exist an error (not receive the same byte). I use IRQ pin for detecting interrupts. Except this the code work fine. Is it possible exists any dependence by SPI ? Any suggestions? Sorry if I couldn't explain it more detailed. Thanks in advance.
Best Regards! |
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princejude
Joined: 07 Aug 2010
Posts: 72
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| Posted: Fri Aug 05, 2011 5:44 am |
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Hello to all,
Pls i will like to use this Randy's nRF24L01 Driver in my project. But i have some questions.
My observation from the implementing the driver sample code is that the nRF24L01 will transmit data receive through the PIC MCU serial (RS232 USART) port:
| Code: | /************ Process Data Packet *************************/
#INT_RDA
void rs232()
{
gets(packet);
data=true;
}
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and
| Code: |
if(data)
{
data=false;
[b] rf_transmit(packet);[/b]
}
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Now the question is how can i edit this code to transmit my own specified data like character, integer or string(eg 0x02, 'A', "HELLO WORLD").
The aim of my project is to build a simple RF remote control. And the operation is that the Transmitter will transmit some integer or strings (0x01,0x02) (if some button press)to the Receiver and if Receiver receives 0x01 it will ON first LED and if it receives 0x02 it will ON the second LED. |
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carkissm
Joined: 09 Nov 2011
Posts: 1
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| Posted: Wed Nov 09, 2011 5:08 am |
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I need connect the module NRF24L01 to pic18f2550, anyone have the schematic for help me.
thanks. |
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Eduardo__
Joined: 23 Nov 2011
Posts: 197
Location: Brazil
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| Posted: Fri Feb 03, 2012 10:43 am |
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Dear princejude.
It´s simple to transmit a "HELLO WORLD" string with nRF24L01+
I made a driver for that.
See at http://www.ccsinfo.com/forum/viewtopic.php?t=47351&highlight=nrf24l01
You can use the command: | Code: | | RF24_TX_putbuffer(false,11, "HELLO WORLD"); //Transmit 11bytes data(text string) to actual address(default_config address) |
But it requires a | Code: | | #device PASS_STRINGS=IN_RAM |
directive at the begining of your uC programm.
_________________
Eduardo Guilherme Brandt |
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zamzam23
Joined: 25 Aug 2010
Posts: 47
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| Posted: Sat Jan 19, 2013 1:10 pm |
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| Quote: | // Enable PORTB.0 interrupt
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why use ext int? |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Sat Jan 19, 2013 5:28 pm |
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| zamzam23 wrote: | | Quote: | // Enable PORTB.0 interrupt
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why use ext int? |
Zamzam, don't waste your time. The code as posted by Randy is full of bugs and a bad starting point for your own project. Better have a look at one of the other two projects mentioned in this thread that have proved to be working. |
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zamzam23
Joined: 25 Aug 2010
Posts: 47
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| which code |
| Posted: Sun Jan 27, 2013 11:43 am |
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Which code do you advise for me? do you have any?
Eduardo__'s code is very complex and I don't know if it is working or not. |
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UenX
Joined: 16 Aug 2012
Posts: 6
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| nRF24L01 can send, cannot receive RF data on PIC18F2550. |
| Posted: Wed Mar 06, 2013 9:56 am |
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Hi Eduardo.
Using your library, nRF24L01 can send, but cannot receive RF data on a PIC18F2550.
The same code ( config, init ) works well on PIC16F887.
Supply voltage for nRF24L01 is 3.6V, PIC uses 5V
Now it (my nRF24L01+ 2550 circuit ) only works ( being able to receive data ) when I plug my PIC programmer circuit on it. Such a strange behavior !
I believe that 's a hardware problem ( especially voltage problem ), but I still can not figure it out after using all of my debugging tricks.
If you have any PIC18F2550 there, could you please do a test on it?
Thank you !  |
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Eduardo__
Joined: 23 Nov 2011
Posts: 197
Location: Brazil
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| Posted: Wed Mar 06, 2013 11:18 am |
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Are you using software or hardware Spi?
Try software spi also!
What is the supply voltage?
It must be between 2.5 and 3.6V.
I´ve used hardware/software SPI with success in PIC18F24J11(with DMA), PIC18F24J11(with DMA), PIC16F876A(no DMA)
I´ve used software SPI with success in PIC16F628A
Good Luck!
_________________
Eduardo Guilherme Brandt |
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UenX
Joined: 16 Aug 2012
Posts: 6
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| Posted: Wed Mar 06, 2013 4:58 pm |
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| Eduardo__ wrote: | Are you using software or hardware Spi?
Try software spi also!
What is the supply voltage?
It must be between 2.5 and 3.6V.
I´ve used hardware/software SPI with success in PIC18F24J11(with DMA), PIC18F24J11(with DMA), PIC16F876A(no DMA)
I´ve used software SPI with success in PIC16F628A
Good Luck! |
Thank you. I'm using software SPI. I believe SPI is working properly, cause the transmitting tasks got no problem. And the receiving feature also works when I plug my PIC programmer on the circuit. I've tried with hardware SPI, though.
Supplying a 5V voltage for the PIC, I've tried with all voltage from 1.9 to 3.6 for nRF24 ( I use a LM317 Voltage Regulator IC )
The nRF24L01's datasheet said it has 5V tolerant inputs, but didnt say whether it can create a 5V voltage on its outputs.
Some people also mention something related to my problem :
http://www.microchip.com/forums/m451409.aspx
https://forum.sparkfun.com/viewtopic.php?f=13&t=4904&start=0
I've also tried using the same voltage for PIC and nRF24 ( 3.21V ) and it worked like a charm on my PIC18F4550 breadboard. But no lucks when I try to reassemble it again. Transmitting is always OK, but nothing happens at Receiving mode.
Now i have no way to explain to my thesis advisor ( this is part of my final year project at university ). A little sad :D
May be i will do another test after finishing this project to figure this problem out ( make some PCBs with unique adjustable voltage for both PIC and nRF24 ) and post back the result here.
Thanks again. |
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teletype-guy
Joined: 11 Oct 2005
Posts: 8
Location: AZ
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UenX
Joined: 16 Aug 2012
Posts: 6
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| Re: hardware -- mixing 5V and 3.3V stuff |
| Posted: Thu Apr 04, 2013 11:29 am |
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Thank you! I'll carefully read your post and do an experiment later ( currently I'm busy with another project ) |
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