Nordic nRF24L01+

horkesley

Hi,

I plan to use the nRF24l01+ to communicate from a PIC based system to a PC fitted with a standard WiFi dongle.

The PIC will be emulating a keyboard scanner, similar to the HT82K629.

This produces a clock and data output.

I don't understand how the RF module will transmit these two signals.

I know this is standard practice as I have seen similar arrangements in use.

Any advise will be appreciated.

Regards,

SRLM

Sorry, doesn't look like it will be possible. The nRF24L01+ uses SPI, and so can only transmit the one stream of data. You'll need to have something at the receiving end to get the keycodes and convert them to keystrokes (maybe an a HID)

First, I don't think it's possible to do Wifi (a suite of communication protocols) over the nRF24L01+ (hardware), despite both being 2.4GHz.

Next, a standard WiFi dongle will not be able to implement a HID type. You'd need something else.

I would recommend transmitting the keycodes as follows:

PIC->nRF24L01+->nRF24L01+->PIC->Computer

You say this is "standard practice". Can you provide links?

If you need help with implementing this specifically on the Pic, you'll want to try a different forum with more expertise. These Parallax forums are for BS2, SX, Javalin, and Propeller processors and the Parallax hardware.

horkesley

Thanks for the reply.

Sorry I am on the wrong forum, I came across this while searching about Nordic products.

But as a reply.

My client has given me a PCB assembly which he has taken out of a wireless PC keyboard.

The board has a SPCP02, key matrix scanner, this produces clock and data outputs. A nRF24L01 and a small EEPROM.

I believe the EEPROM some how configures the nRF24L01.

Going back a stage, if you take the clock and data signals and feed them into a standard PC USB socket, no additional hardware of software, it behaves as a PC keyboard.

This board does the same thing via RF and uses a standard of the shelf USB dongle.

Hence my question, how does it do it?

Best regards,

SRLM

You've actually done that? Hardwired (or at least looked at) the signals that go to the nRF24L01+ and wired them directly to the USB port?

I'm unconvinced that you can use the nRF24L01+ to directly interface to WifI signals or use it to emulate as a HID. The nRF24L01+ has only SPI as the interface method (not keyboard interfaces, or Ethernet, or anything else). Here is one appnote that describes the system I did above: http://www.atmel.com/Images/doc7650.pdf Note that it has two nRF24L01+s, and two processors.

Of course, you shouldn't take my word for it. Pull out a scope or a digital logic analyzer and check the signals. If you use something like the Logic16 then it will be able to automatically decipher the protocol. (ps: if you do that, then post back here! I'm curious about this now).