nrf24l01 Some data is loss!! please help

jele · February 1, 2008, 12:22pm

hi everybody :lol:

I test tutorial 2 (from diyembedded.com )i send data package(100 byte) but it return is 98 byte and data not sure , Why?.
I test tutorial 3(Multiple pipe) i ping each pipe and data is loss and i change position is faraway ([Remote] ---------------10 m-------------[Local]) it can ping about 10 % and some pipe ,Why?

MCU p18F8720 , clock 40 MHz PLL ,Wireless DCBT-24N(chip nrf24l01) , boudrate 9600 bps, and good toturial from www.diyembedded.com

Thank you all!

brennen · February 1, 2008, 2:07pm

In RF in general, you’re going to lose some packets, mainly due to other RF interference, physical objects between receiver and transmitter, or not enough TX power for the distance that seperates the transmitter and receiver. 2.4 GHz is a bit notorious for not being able to go through walls, etc.

The easiest and cheapest way to get around dropped packets with the 24L01 is to use the auto-acknowledge and auto-retransmit features that are built into the hardware. This costs virtually nothing in terms of software, except that you have to make sure that the packet that you tried to send was actually received on the other end.

Other ways to help with dropped packets are to use antennas with higher gain (whip antennas will generally perform far better than chip antennas) or even to go as far as to use an external power amplifier (Nordic has an app note for adding a PA to a 2401A, but this could easily be modified to be used with the 24L01).

jele · February 2, 2008, 8:38am

Hi

When i send data package >3 Byte data is change position

I sent 1234567890

but it recceive is 9012345678

or

Sent 12345

Receive 45123

This my code

LOCAL::

while(1)//main program loop

{

data = 0;

if(DataRdy1USART( ))

{

data = getc1USART();

nrf24l01_write_tx_payload(&data, 1, true);

while(Busy1USART( ));

while(!(nrf24l01_irq_pin_active() && nrf24l01_irq_tx_ds_active()));

nrf24l01_irq_clear_all();

}

ToggleLED(); //toggle the on-board LED as visual indication that the loop has completed

}//While(1)…

nrf24l01_initialize(nrf24l01_CONFIG_DEFAULT_VAL | nrf24l01_CONFIG_PWR_UP, //1 byte CRC, powered up

true, //enable CE

nrf24l01_EN_AA_ENAA_NONE, //Disable auto-ack on all pipes

nrf24l01_EN_RXADDR_DEFAULT_VAL, //enable receive on all pipes

nrf24l01_SETUP_AW_DEFAULT_VAL, //5-byte addressing

nrf24l01_SETUP_RETR_DEFAULT_VAL, //not using auto-ack, so use default

nrf24l01_RF_CH_DEFAULT_VAL, //RF channel 3

nrf24l01_RF_SETUP_DEFAULT_VAL, //2 Mbps, 0 dBm

NULL, //nrf24l01_RX_ADDR_P0_DEFAULT_VAL(E7:E7:E7:E7:E7)

NULL, //nrf24l01_RX_ADDR_P1_DEFAULT_VAL(C2:C2:C2:C2:C2)

nrf24l01_RX_ADDR_P2_DEFAULT_VAL, //(C2:C2:C2:C2:[C3])

nrf24l01_RX_ADDR_P3_DEFAULT_VAL, //(C2:C2:C2:C2:[C4])

nrf24l01_RX_ADDR_P4_DEFAULT_VAL, //(C2:C2:C2:C2:[C5])

nrf24l01_RX_ADDR_P5_DEFAULT_VAL, //(C2:C2:C2:C2:[C6])

NULL, //default TX address(E7:E7:E7:E7:E7)

1, //1 byte paylaod width on pipe 0

nrf24l01_RX_PW_P1_DEFAULT_VAL, //0x00

nrf24l01_RX_PW_P2_DEFAULT_VAL, //0x00

nrf24l01_RX_PW_P3_DEFAULT_VAL, //0x00

nrf24l01_RX_PW_P4_DEFAULT_VAL, //0x00

nrf24l01_RX_PW_P5_DEFAULT_VAL); //0x00

REMOTE::

while(TRUE)

{

//wait until a packet has been received

while(!(nrf24l01_irq_pin_active() && nrf24l01_irq_rx_dr_active()));

nrf24l01_read_rx_payload(&data, 1); //read the packet into data

nrf24l01_irq_clear_all(); //clear all interrupts in the 24L01

putc1USART(data);

ToggleLED(); //toggle the on-board LED as visual indication that the loop has completed

} // While True …

nrf24l01_initialize(nrf24l01_CONFIG_DEFAULT_VAL | nrf24l01_CONFIG_PWR_UP | nrf24l01_CONFIG_PRIM_RX, //1 byte CRC, powered up, RX

true, //enable CE

nrf24l01_EN_AA_ENAA_NONE, //disable auto-ack on all pipes

nrf24l01_EN_RXADDR_ERX_ALL, //enable receive on all pipes