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CC1100E. Asynchronous mode problem.

George Sand
Prodigy 210 points
Other Parts Discussed in Thread: CC1100E

Hi,

I have custom board with CC1100E as a transmitter. SPI communication works fine. According to the manual and SmartRF setting PKT_FORMAT=3 will turn GDO0 into a TX input. Do I need to configure anything else before I may apply signal to the GDO0 pin and start transmission? Is GDO0 an input now? The manual mensions something about GDO0_Z_EN_N configuration settings for GDO2 to use GDO0 as input.

What kind of TX signal can I transmit? Can I directly control RF output by toggling GDO0 or it should be NRZ or something? As for now I need RF modulated with square wave.

Thanks

  • 0
    Mastermind 8170 points

    Using asynchronous transparent (serial) mode with OOK (On Off Keying)  modulation and applying a square wave to GDO0 you can get a fairly good square wave on the RF output.  Note that the GDO0 pin is over sampled by 5.  Use RF Studio to determine all of  the register values. My guess is you will have to write the code to control transmit, receive and idle. This mode is seldom used; I do not know if there are code examples available.

    You will need to write 0x2D to 0x02: IOCFG0 to enable GDO0 as the input.

    Configuration of GDO0 by way of example (see page 61);

             Bit
    7 6 5 4 3 2 1 0
    0                              To turn off of the temperature sensor
       0                           Inverted output not selected
          1 0 1 1 0 1         0x2D  which per table 33 page 52 selects GDO0 as an input
    0 0 1 0 1 1 0 1 =      0x2D is written to register 0x02

  • 0 in reply to H Stewart
    Prodigy 210 points

    Thank you.

    What manual are you referring to? CC1100E’s one has no example on page 61 or a table on page 52.

    I was looking at the similar table in my copy and decided to try 0x2E – high Z. My understanding was that 0x2D is to control GDO0 state with GDO2 pin to switch between input-output.

    I am looking  for the proper way to switch into TX .

     

  • 0 in reply to George Sand
    Mastermind 8170 points

    Ah, the page numbers are from a older spec.  The correct numbers are page 55 and 64. The outputs from the table on page 55 can appear on GDO0,1 or 2 depending which register you write to.  When you write a 1 to GDOx 0x2E the GDOx pin is place in high z.   x can be 0 , 1 or 2.