Pascal Langer 0844ec2efd Add more protocols which can run with the CC2500
Use CC2500 only when emulating NRF250K/XN297_250K
2021-02-16 19:06:23 +01:00

266 lines
7.4 KiB
C++

#if defined(CC2500_INSTALLED) || defined(NRF24L01_INSTALLED)
#include "iface_xn297.h"
#endif
#ifdef NRF24L01_INSTALLED
void XN297_SetTXAddr(const uint8_t* addr, uint8_t len)
{
if (len > 5) len = 5;
if (len < 3) len = 3;
uint8_t buf[] = { 0x55, 0x0F, 0x71, 0x0C, 0x00 }; // bytes for XN297 preamble 0xC710F55 (28 bit)
xn297_addr_len = len;
if (xn297_addr_len < 4)
for (uint8_t i = 0; i < 4; ++i)
buf[i] = buf[i+1];
NRF24L01_WriteReg(NRF24L01_03_SETUP_AW, len-2);
NRF24L01_WriteRegisterMulti(NRF24L01_10_TX_ADDR, buf, 5);
// Receive address is complicated. We need to use scrambled actual address as a receive address
// but the TX code now assumes fixed 4-byte transmit address for preamble. We need to adjust it
// first. Also, if the scrambled address begins with 1 nRF24 will look for preamble byte 0xAA
// instead of 0x55 to ensure enough 0-1 transitions to tune the receiver. Still need to experiment
// with receiving signals.
memcpy(xn297_tx_addr, addr, len);
}
void XN297_SetRXAddr(const uint8_t* addr, uint8_t len)
{
if (len > 5) len = 5;
if (len < 3) len = 3;
uint8_t buf[] = { 0, 0, 0, 0, 0 };
memcpy(buf, addr, len);
memcpy(xn297_rx_addr, addr, len);
for (uint8_t i = 0; i < xn297_addr_len; ++i)
{
buf[i] = xn297_rx_addr[i];
if(xn297_scramble_enabled)
buf[i] ^= xn297_scramble[xn297_addr_len-i-1];
}
NRF24L01_WriteReg(NRF24L01_03_SETUP_AW, len-2);
NRF24L01_WriteRegisterMulti(NRF24L01_0A_RX_ADDR_P0, buf, 5);
}
void XN297_Configure(uint8_t flags)
{
xn297_crc = !!(flags & _BV(NRF24L01_00_EN_CRC));
flags &= ~(_BV(NRF24L01_00_EN_CRC) | _BV(NRF24L01_00_CRCO));
NRF24L01_WriteReg(NRF24L01_00_CONFIG, flags & 0xFF);
}
void XN297_SetScrambledMode(const uint8_t mode)
{
xn297_scramble_enabled = mode;
}
void XN297_WritePayload(uint8_t* msg, uint8_t len)
{
uint8_t buf[32];
uint8_t last = 0;
if (xn297_addr_len < 4)
{
// If address length (which is defined by receive address length)
// is less than 4 the TX address can't fit the preamble, so the last
// byte goes here
buf[last++] = 0x55;
}
for (uint8_t i = 0; i < xn297_addr_len; ++i)
{
buf[last] = xn297_tx_addr[xn297_addr_len-i-1];
if(xn297_scramble_enabled)
buf[last] ^= xn297_scramble[i];
last++;
}
for (uint8_t i = 0; i < len; ++i)
{
// bit-reverse bytes in packet
buf[last] = bit_reverse(msg[i]);
if(xn297_scramble_enabled)
buf[last] ^= xn297_scramble[xn297_addr_len+i];
last++;
}
if (xn297_crc)
{
uint8_t offset = xn297_addr_len < 4 ? 1 : 0;
crc = 0xb5d2;
for (uint8_t i = offset; i < last; ++i)
crc16_update( buf[i], 8);
if(xn297_scramble_enabled)
crc ^= pgm_read_word(&xn297_crc_xorout_scrambled[xn297_addr_len - 3 + len]);
else
crc ^= pgm_read_word(&xn297_crc_xorout[xn297_addr_len - 3 + len]);
buf[last++] = crc >> 8;
buf[last++] = crc & 0xff;
}
NRF24L01_WritePayload(buf, last);
}
void XN297_WriteEnhancedPayload(uint8_t* msg, uint8_t len, uint8_t noack)
{
uint8_t packet[32];
uint8_t scramble_index=0;
uint8_t last = 0;
static uint8_t pid=0;
// address
if (xn297_addr_len < 4)
{
// If address length (which is defined by receive address length)
// is less than 4 the TX address can't fit the preamble, so the last
// byte goes here
packet[last++] = 0x55;
}
for (uint8_t i = 0; i < xn297_addr_len; ++i)
{
packet[last] = xn297_tx_addr[xn297_addr_len-i-1];
if(xn297_scramble_enabled)
packet[last] ^= xn297_scramble[scramble_index++];
last++;
}
// pcf
packet[last] = (len << 1) | (pid>>1);
if(xn297_scramble_enabled)
packet[last] ^= xn297_scramble[scramble_index++];
last++;
packet[last] = (pid << 7) | (noack << 6);
// payload
packet[last]|= bit_reverse(msg[0]) >> 2; // first 6 bit of payload
if(xn297_scramble_enabled)
packet[last] ^= xn297_scramble[scramble_index++];
for (uint8_t i = 0; i < len-1; ++i)
{
last++;
packet[last] = (bit_reverse(msg[i]) << 6) | (bit_reverse(msg[i+1]) >> 2);
if(xn297_scramble_enabled)
packet[last] ^= xn297_scramble[scramble_index++];
}
last++;
packet[last] = bit_reverse(msg[len-1]) << 6; // last 2 bit of payload
if(xn297_scramble_enabled)
packet[last] ^= xn297_scramble[scramble_index++] & 0xc0;
// crc
if (xn297_crc)
{
uint8_t offset = xn297_addr_len < 4 ? 1 : 0;
crc = 0xb5d2;
for (uint8_t i = offset; i < last; ++i)
crc16_update( packet[i], 8);
crc16_update( packet[last] & 0xc0, 2);
if (xn297_scramble_enabled)
crc ^= pgm_read_word(&xn297_crc_xorout_scrambled_enhanced[xn297_addr_len-3+len]);
//else
// crc ^= pgm_read_word(&xn297_crc_xorout_enhanced[xn297_addr_len - 3 + len]);
packet[last++] |= (crc >> 8) >> 2;
packet[last++] = ((crc >> 8) << 6) | ((crc & 0xff) >> 2);
packet[last++] = (crc & 0xff) << 6;
}
NRF24L01_WritePayload(packet, last);
pid++;
if(pid>3)
pid=0;
}
boolean XN297_ReadPayload(uint8_t* msg, uint8_t len)
{ //!!! Don't forget if using CRC to do a +2 on any of the used NRF24L01_11_RX_PW_Px !!!
uint8_t buf[32];
if (xn297_crc)
NRF24L01_ReadPayload(buf, len+2); // Read payload + CRC
else
NRF24L01_ReadPayload(buf, len);
// Decode payload
for(uint8_t i=0; i<len; i++)
{
uint8_t b_in=buf[i];
if(xn297_scramble_enabled)
b_in ^= xn297_scramble[i+xn297_addr_len];
msg[i] = bit_reverse(b_in);
}
if (!xn297_crc)
return true; // No CRC so OK by default...
// Calculate CRC
crc = 0xb5d2;
//process address
for (uint8_t i = 0; i < xn297_addr_len; ++i)
{
uint8_t b_in=xn297_rx_addr[xn297_addr_len-i-1];
if(xn297_scramble_enabled)
b_in ^= xn297_scramble[i];
crc16_update( b_in, 8);
}
//process payload
for (uint8_t i = 0; i < len; ++i)
crc16_update( buf[i], 8);
//xorout
if(xn297_scramble_enabled)
crc ^= pgm_read_word(&xn297_crc_xorout_scrambled[xn297_addr_len - 3 + len]);
else
crc ^= pgm_read_word(&xn297_crc_xorout[xn297_addr_len - 3 + len]);
//test
if( (crc >> 8) == buf[len] && (crc & 0xff) == buf[len+1])
return true; // CRC OK
return false; // CRC NOK
}
uint8_t XN297_ReadEnhancedPayload(uint8_t* msg, uint8_t len)
{ //!!! Don't forget do a +2 and if using CRC add +4 on any of the used NRF24L01_11_RX_PW_Px !!!
uint8_t buffer[32];
uint8_t pcf_size; // pcf payload size
if (xn297_crc)
NRF24L01_ReadPayload(buffer, len+4); // Read pcf + payload + CRC
else
NRF24L01_ReadPayload(buffer, len+2); // Read pcf + payload
pcf_size = buffer[0];
if(xn297_scramble_enabled)
pcf_size ^= xn297_scramble[xn297_addr_len];
pcf_size = pcf_size >> 1;
for(int i=0; i<len; i++)
{
msg[i] = bit_reverse((buffer[i+1] << 2) | (buffer[i+2] >> 6));
if(xn297_scramble_enabled)
msg[i] ^= bit_reverse((xn297_scramble[xn297_addr_len+i+1] << 2) |
(xn297_scramble[xn297_addr_len+i+2] >> 6));
}
if (!xn297_crc)
return pcf_size; // No CRC so OK by default...
// Calculate CRC
crc = 0xb5d2;
//process address
for (uint8_t i = 0; i < xn297_addr_len; ++i)
{
uint8_t b_in=xn297_rx_addr[xn297_addr_len-i-1];
if(xn297_scramble_enabled)
b_in ^= xn297_scramble[i];
crc16_update( b_in, 8);
}
//process payload
for (uint8_t i = 0; i < len+1; ++i)
crc16_update( buffer[i], 8);
crc16_update( buffer[len+1] & 0xc0, 2);
//xorout
if (xn297_scramble_enabled)
crc ^= pgm_read_word(&xn297_crc_xorout_scrambled_enhanced[xn297_addr_len-3+len]);
#ifdef XN297DUMP_NRF24L01_INO
else
crc ^= pgm_read_word(&xn297_crc_xorout_enhanced[xn297_addr_len - 3 + len]);
#endif
uint16_t crcxored=(buffer[len+1]<<10)|(buffer[len+2]<<2)|(buffer[len+3]>>6) ;
if( crc == crcxored)
return pcf_size; // CRC OK
return 0; // CRC NOK
}
// End of XN297 emulation
#endif