Enhanced Shockburst Transmitter (PTX)

Functions
int	main ()
	Main function. More...

Configuration
static uint8_t	my_tx_payload [TX_PAYLOAD_LENGTH]
	Payload to send to PRX.
static uint8_t	my_rx_payload [NRF_ESB_CONST_MAX_PAYLOAD_LENGTH]
	Placeholder for received ACK payloads from PRX.
#define	PIPE_NUMBER   0
	We use pipe 0 in this example.
#define	BUTTONS   NRF_GPIO_PORT_SELECT_PORT0
	GPIO port for reading from buttons.
#define	LEDS   NRF_GPIO_PORT_SELECT_PORT1
	GPIO port for writing to LEDs.
#define	TX_PAYLOAD_LENGTH   1
	We use 1 byte payload length when transmitting.

ESB callback function definitions
void	nrf_esb_tx_success (uint32_t tx_pipe, int32_t rssi)
	TX success callback. More...
void	nrf_esb_tx_failed (uint32_t tx_pipe)
	TX failed callback (PTX mode only). More...
void	nrf_esb_rx_data_ready (uint32_t rx_pipe, int32_t rssi)
	RX data ready callback. More...
void	nrf_esb_disabled (void)
	Disabled callback. More...

Detailed Description

This project requires that a device running the Enhanced Shockburst Transmitter (PTX) example be used as a counterpart for receiving the data. This can be on either nRF51 device or a nRF24Lxx device running the esb_ptx_example in the nRFgo SDK.

This example sends a packet and adds a new packet to the TX queue every time it receives an ACK. The contents of GPIO Port BUTTONS are sent in the first payload byte (byte 0). The host sends an acknowledgement that is received by the device. The contents of the first payload byte of the acknowledgement is output on GPIO Port LEDS.

Function Documentation

int main

(

void

)

Returns

ANSI required int return type.

void nrf_esb_tx_success	(	uint32_t	tx_pipe,
		int32_t	rssi
	)

In PTX mode this function is called after the PTX has sent a packet and received the corresponding ACK packet from a PRX.

In PRX mode this function is called after a payload in ACK is assumed successfully transmitted, that is when the PRX received a new packet (new PID or CRC) and the previous ACK sent to a PTX contained a payload.

Parameters

tx_pipe	The pipe on which the ACK packet was received.
rssi	Received signal strength indicator in dBm of measured ACK.

As the RSSI measurement requires a minimum on-air duration of the received packet, the measured RSSI value will not be reliable when ALL of the following criteria are met:

• Datarate = 2 Mbps
• Payload length = 0
• CRC is off

void nrf_esb_tx_failed

(

uint32_t

tx_pipe

)

This is called after the maximum number of TX attempts were reached for a packet. The packet is deleted from the TX FIFO.

Note that when NRF_ESB_PACKET_NO_ACK is used this callback is always made after sending a packet.

See Also

nrf_esb_set_max_number_of_tx_attempts().

Parameters

tx_pipe

The pipe that failed to send a packet.

void nrf_esb_rx_data_ready	(	uint32_t	rx_pipe,
		int32_t	rssi
	)

PTX mode: This is called after an ACK is received from a PRX containing a payload.

PRX mode: This is called after a packet is received from a PTX ACK is received from a PRX containing a payload.

Parameters

rx_pipe	is the pipe on which a packet was received. This value must be < NRF_ESB_CONST_PIPE_COUNT.
rssi	Received signal strength indicator in dBm of packet.

As the RSSI measurement requires a minimum on-air duration of the received packet, the measured RSSI value will not be reliable when ALL of the following criteria are met:

• Datarate = 2 Mbps
• Payload length = 0
• CRC is off

void nrf_esb_disabled

(

void

)

This is called after ESB enters the disabled state. There is no further CPU use by ESB, the radio is disabled and the timer is powered down.