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nRF24AP2-USB Product Specification

yet ready. Finally, when the DATA is received successfully by the host it will send an ACK handshake

packet.

Figure 18. Status stage

For a control read transfer the status stage is used by the host to acknowledge that it has received the data

successfully. The status stage will start with an OUT token packet followed by a DATA packet of zero

length. The nRF24AP2-USB will reply with an ACK handshake packet if it received the status packets

successfully. A STALL will be returned if an error occurred at any point during the processing of the trans-

fer. A NAK will be returned if the nRF24AP2-USB is busy and requires the host to repeat the status stage.

5.3.7

Host Command flow

All other communication between the host and nRF24AP2 USB will be handled through USB drivers and

libraries available from ANT. These USB libraries interact with the device through two bulk endpoints

(EP1IN and EP1OUT). The use of the host interface is documented in ANT Message Protocol and Usage

detailed in that document are passed between the host and the nRF24AP2-USB inside the data packet

portion of USB bulk transfers.

Table 14. Driver/application USB parameters for communication with nRF24 AP2-USB

5.3.7.1

Bulk transfers

Bulk transfers will be used to transport the serial messages specified by the ANT command interface. The

nRF24AP2-USB supports a maximum bulk data packet size of 64 bytes.

Figure 19. Bulk IN transfer

USB parameters

Value

VID (Vendor Identification)

0x0FCF

PID (Product Identification)

0x1008

IN endpoint address

0x81

OUT endpoint address

0x01

ACK

OUT

DATA0

(0 Bytes)

STALL

(error)

NAK

(not ready)

DATA

IN

ACK

STALL

(error)

NAK

(not ready)

nRF24AP2-USB

Host