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--- doc:crazyradio:usb:index [2012-05-11 07:36]
arnaud
+++ doc:crazyradio:usb:index [2012-05-15 00:03]
arnaud [Dongle configuration]
@@ Line 33: / Line 33: @@
 The nrf24L chips provides 126 Channels of 1MHz from 2400MHz to 2525MHz. The channel parameter shall be between 0 and 125 (if not the command will be ignored).
-The radio channel is set as soon as the setup transaction is completed which takes about 1ms. The new frequency is going to be used for the following transfered packets.
+The radio channel is set as soon as the setup transaction is completed which takes about 1ms. The new frequency is going to be used for the following transfered packets. Default value for the radio channel is 2.
 === Set radio address ===
@@ Line 39: / Line 39: @@
 ^ bmRequestType ^ bRequest                 ^ wValue   ^ wIndex ^ wLength ^ data    ^
 |          0x40 | SET_RADIO_ADDRESS (0x02) | Zero     | Zero   | 5       | Address |
+The packet sent by the radio contains a 5 bytes address. The same address must be configured in the receiver for the communication to work.
+The address must follow the requirement of the section 6.4.3.2 of the nRF24LU1 documentation:
+<code>
+Addresses where the level shifts only one time (that is, 000FFFFFFF) can often be detected in
+noise and can give a false detection, which may give a raised Packet-Error-Rate. Addresses
+as a continuation of the preamble (hi-low toggling) raises the Packet-Error-Rate.
+</code>
+The default address is 0xE7E7E7E7E7.
 === Set datarate ===
@@ Line 53: / Line 65: @@
 === Set radio power ===
+^ bmRequestType ^ bRequest                 ^ wValue   ^ wIndex ^ wLength ^ data    ^
+|          0x40 | SET_RADIO_POWER (0x04)   | Power    | Zero   | Zero    | None    |
 === Configure auto retry (ARD/ARC) ===
-=== Continuous carrier mode ===
+^ bmRequestType ^ bRequest                 ^ wValue   ^ wIndex ^ wLength ^ data    ^
+|          0x40 | SET_RADIO_ARD (0x05)     | ARD      | Zero   | Zero    | None    |
+|          0x40 | SET_RADIO_ARC (0x06)     | ARC      | Zero   | Zero    | None    |
-=== Launch bootloader ===
+After sending a packet the radio automatically waits for an acknowledge. ARD and ARC permits to configure the delay the radio waits for the acknowledge and the number of time the transfer will be retried in case the acknowledge is not received in that delay.
+The delay ARD depends of the length, in second, of the ack packed. This depends of the datarate and the Payload length contained in the Ack packet. The ARD can be configured either by step of 250us or by ack payload length. If the ack payload length is configured the time will be recalculated automatically even if the datarate is changed. To set the Ack payload lenght the bit 7 of Ard must be set (length | 0x80)
+Possible values for ARD:
+^ Value ^ ARD wait  time ^
+|  0x00 | 250us          |
+|  0x01 | 500us          |
+|   ... | ...            |
+|  0x0F | 4000us         |
+^ Value ^ Ack payload length ^
+|  0x80 | 0Byte              |
+|  0x81 | 1Byte              |
+|   ... | ...                |
+|  0xA0 | 32Bytes            |
+ARC configures the number of time the radio will retry a transfer if the Ack has not been received, it can be set from 0 to 15.
+By default ARD=32Bytes (0xA0) and ARC=3.
+=== Continuous carrier mode ===
+=== Launch bootloader ===
 ==== Data transfer ====

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