nRF24L01+ - EN_AA Enabled but acting as if it were disabled.

[dsbaha]

Hi, I have two different types of nRF24L01+ modules, both behave differently.

The "troublesome" module always has TX_DS asserted after a transmit, which is the same behavior described by the v2.0 documentation as if AUTO_ACK is disabled.

However, AUTO_ACK is set to 0x3f (all pipes).

Anyone have any suggestions?

Output of "good" module, which is the intended behavior;

>Sending...
read_register(1d,05) <br>
read_register(00,0f) <br>
write_register(00,0e) <br>
read_register(02,3f) <br>
write_register(02,3f) <br>
write_register(11,20) <br>
[Writing 16 bytes 0 blanks] <br>
read_register(17,01) <br>
read_register(17,01) <-- never receives an auto_ack (because no one is listening on other side)<br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
write_register(07,10) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
read_register(17,01) <br>
write_register(07,10) <br>
read_register(00,0e) <br>
read_register(00,0e) <br>
write_register(00,0f) <br>
write_register(07,70) <br>
read_register(1d,05) <br>
failed. <br>

Output of "troublesome" module, which is NOT the intended behavior;

> Sending... <br>
read_register(1d,05) <br>
read_register(00,0f) <br>
write_register(00,0e) <br>
read_register(02,3f) <br>
write_register(02,3f) <br>
write_register(11,20) <br>
[Writing 16 bytes 0 blanks] <br>
read_register(17,01) <br>
read_register(17,11) <-- couldn't have received an auto_ack, again EN_AA is set to 0x3f <br>
read_register(00,0e) <br>
read_register(00,0e) <br>
write_register(00,0f) <br>
write_register(07,70) <br>
read_register(1d,05) <br>
ok. <br>

[Asbjørn]

It sounds like you have one module with the nRF24L01+ and one module with a nRF24L01. The nRF24L01 doesn't have the FEATURE register enabled by default. It would behave just as you describe. The nRF24L01 has the registers and functionality available, but you have to enable the FEATURE register first and then you will have it all available to your application.

[dsbaha]

So, I've played around with the FEATURE register. If its disabled, then any change I attempt to make it does not stick (feature register is always 0). When I turn on the FEATURE register, then changes will happen (e.g., FEATURE register is not 0). So I think its getting enabled.

I can also confirm that RXP0 and TX are set to the same address.

The modules I bought are these; link text

[Asbjørn]

You bought the set of 10 modules? How many are "troublesome" and how many of them are working as expected?