NRF24L01+ no transmit

[SKRIM]

I'm trying to get a module with an NFR24L01+ on board to send a simple data transmission from a pic micro but after a couple of days of trying various combinations without success i'm asking for help.

I can see data and commands being clocked in and out of the SPI. the pulse on CE is present on the chip. VDD_PA never rises. No power noted on a monitoring SA. Status 0x0E returned from chip.

My send byte code:

unsigned char SPI_RW(unsigned char DATA) {
  while (! SSPIF);
  SSPSTATbits.BF = 0;
  SSPBUF = DATA;
  while(SSPSTATbits.BF == 0);
  return SSPBUF;
}

My send register code:

unsigned char SPI_RW_Register(unsigned char reg, unsigned char value){
  int status;
  CSN_PIN=0;
  status=SPI_RW(reg);
  SPI_RW(value);
  CSN_PIN=1;
  return status;
}

My write buffer code:

unsigned char SPI_Write_Buffer(unsigned char reg, unsigned char *pBuf, unsigned char bytes){
  unsigned char status,i;
  CSN_PIN=0;                   // Set CSN low, init SPI tranaction
  status = SPI_RW(reg);             // Select register to write to and read status unsigned char
  for(i=0;i<bytes; i++)             // then write all unsigned char in buffer(*pBuf)
  {
    SPI_RW(*pBuf++);
  }
  CSN_PIN=1;
  return(status);                  // return nRF24L01 status unsigned char
}

My init code:

  CE_PIN=0;
    SPI_RW_Register(WRITE_REG + CONFIG,0x00110000);// PRX, no CRC , mask a couple of ints
    __delay_ms(100);
    SPI_RW_Register(WRITE_REG + SETUP_RETR,0x00);// autoretransmit off
    SPI_RW_Register(WRITE_REG + SETUP_AW,0x00000011);// address width = 5
    SPI_RW_Register(WRITE_REG + RF_SETUP, 0x00100110); //data rate 250KB 0dBm
    SPI_RW_Register(WRITE_REG + RF_CH,0x02);// set channel
    SPI_Write_Buffer(WRITE_REG + TX_ADDR,TX_ADDRESS,5);
    SPI_Write_Buffer(WRITE_REG + RX_ADDR_P0,TX_ADDRESS,5);
    SPI_RW_Register(WRITE_REG + EN_AA,0x00); //disable auto-ack 

My TX code:

void NRFtx(){
  CE_PIN=0;
  SPI_RW_Register(WRITE_REG + STATUS,0x7e); // clear previous interrupts
  SPI_RW_Register(WRITE_REG + CONFIG,0x00110010);// PTX, no CRC, mask a couple of ints
  __delay_us(150);
  SPI_RW_Command(FLUSH_TX);//clear tx fifo
  SPI_Write_Buffer(WR_TX_PAYLOAD,tx_buf,TX_PAYLOAD_WIDTH);
  CE_PIN=1; 
  __delay_ms(15);
  CE_PIN=0;

}

Can anyone please tell me where i'm going wrong with this?

Thank you,

S

[SKRIM]

I've spent a while this evening running through tests and monitoring the SPI bus along with monitoring current consumption.

There's something very odd going on with these modules. The MISO pin seems to follow the CSN pin. For example if CSN is low than then transitions to high for 7.75us then back to low the MISO pin goes high 2.75us after the CSN low->high and MISO goes low at the same time as CSN. Also, if i remove the CE connection to my breadboard and let the pin float the module will transmit and i see current consumption in excess of 900uA. As soon as i reconnect CE transmission stops.

I have a saleae logic session saved if that's any use to anyone?

S