Diff: nRFBareRadio.cpp

Revision:

0:123cac2364c4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRFBareRadio.cpp	Fri May 17 13:36:56 2019 +0000
@@ -0,0 +1,176 @@
+#include "nRFBareRadio.h"
+
+/*
+#ifdef TARGET_NRF52
+#define RADIO_RECEIVE_EVENT   EVENTS_CRCOK
+#else
+#define RADIO_RECEIVE_EVENT   EVENTS_END
+#endif*/
+
+RadioConfig::RadioConfig() {
+    frequency = 2;                      
+    rate = RADIO_RATE_2M;
+    tx_power = RADIO_TX_0dBm;
+    data_length = 32;                   // compatible to nRF24 (range 1-32)
+    address_length = 5;                 // compatible to nRF24 (range 3-5)
+    use_whitening = RADIO_NO_WHITENING; // compatible to nRF24 (no change)
+    endianness = RADIO_BIGENDIAN;       // compatible to nRF24 (no change)
+    crc_poly = 0x1021;                  // compatible to nRF24 (no change)
+    crc_init = 0xFFFF;                  // compatible to nRF24 (no change)
+}
+
+
+
+// Partially based on a version by Manuel Caballero
+// https://os.mbed.com/users/mcm/
+
+BareRadio::BareRadio() {
+    data_len = 32;
+    for (int i=0; i<data_len; i++) packet[i] = 0;
+    ConfigClock();
+}
+
+int BareRadio::ConfigClock() {
+    int i;
+    
+    NRF_CLOCK->EVENTS_HFCLKSTARTED  =   0; // flag
+    NRF_CLOCK->TASKS_HFCLKSTART     =   1; // start task
+
+    for (i=0; i<10000; i++) {
+        if (NRF_CLOCK->EVENTS_HFCLKSTARTED) return 1;
+        wait_us(10);
+    }
+    return 0; // could not configure timer in 100ms
+}
+
+void BareRadio::Setup(int mode, RadioAddress address, RadioConfig& config) {
+    // According to datasheet, power off and on causes a reset on all registers
+    NRF_RADIO->POWER = ( RADIO_POWER_POWER_Disabled << RADIO_POWER_POWER_Pos ); // POWER OFF
+    wait_us(10);
+    NRF_RADIO->POWER = ( RADIO_POWER_POWER_Enabled  << RADIO_POWER_POWER_Pos ); // POWER ON
+
+    // calculate the BASE0 length based on the total address length
+    // total address length must be in the range [3,5]
+    int BASE0_len = config.address_length - 1;
+    if (BASE0_len < 2) BASE0_len = 2;
+    if (BASE0_len > 4) BASE0_len = 4;
+    
+    data_len = config.data_length;
+
+    // Configure data rate (0=1M, 1=2M, 2=250K, 3=BLE1M)
+    NRF_RADIO->MODE  = ( config.rate << RADIO_MODE_MODE_Pos );
+
+    // Configure packet: NO S0,S1 or Length fields & 8-bit preamble. 
+    // Compatible to nRF24 without dynamic payload
+    NRF_RADIO->PCNF0 = ( 0                            << RADIO_PCNF0_LFLEN_Pos  ) |
+                       ( 0                            << RADIO_PCNF0_S0LEN_Pos  ) |
+                       ( 0                            << RADIO_PCNF0_S1LEN_Pos  )
+    #ifdef TARGET_NRF52
+                     | ( RADIO_PCNF0_S1INCL_Automatic << RADIO_PCNF0_S1INCL_Pos )
+                     | ( RADIO_PCNF0_PLEN_8bit        << RADIO_PCNF0_PLEN_Pos   )
+    #endif
+                     ;
+
+    // Configure static payload length 
+    NRF_RADIO->PCNF1 = ( config.data_length           << RADIO_PCNF1_MAXLEN_Pos) |  // this is to truncate the packet
+                       ( config.data_length           << RADIO_PCNF1_STATLEN_Pos) | // this is to configure the radio
+                       ( BASE0_len                    << RADIO_PCNF1_BALEN_Pos) |
+                       ( config.endianness            << RADIO_PCNF1_ENDIAN_Pos) |
+                       ( config.use_whitening         << RADIO_PCNF1_WHITEEN_Pos);
+
+    // Whitening value
+    NRF_RADIO->DATAWHITEIV = ( ( 0x55 & RADIO_DATAWHITEIV_DATAWHITEIV_Msk ) << RADIO_DATAWHITEIV_DATAWHITEIV_Pos );
+
+    // Configure address Prefix0 and Base0
+    unsigned int addr[5] = {address.A0, address.A1, address.A2, address.A3, address.A4};
+    unsigned int base_address = 0;
+    int i = 0;
+    while (i<BASE0_len) {
+        base_address |= (addr[i] << (i*8));
+        i++;
+    }
+    NRF_RADIO->BASE0   = base_address;
+    NRF_RADIO->PREFIX0 = ( ( addr[i] & RADIO_PREFIX0_AP0_Msk ) << RADIO_PREFIX0_AP0_Pos );
+
+    // Initialize CRC ( two bytes )
+    // Includes address field for nRF24 compatibility
+    NRF_RADIO->CRCCNF    =   (RADIO_CRCCNF_LEN_Two << RADIO_CRCCNF_LEN_Pos) |
+                           (RADIO_CRCCNF_SKIPADDR_Include << RADIO_CRCCNF_SKIPADDR_Pos);
+
+    NRF_RADIO->CRCPOLY   =   ( config.crc_poly     << RADIO_CRCPOLY_CRCPOLY_Pos );
+    NRF_RADIO->CRCINIT   =   ( config.crc_init     << RADIO_CRCINIT_CRCINIT_Pos );
+
+    #ifdef TARGET_NRF52
+    // Enable fast rampup, new in nRF52
+    NRF_RADIO->MODECNF0  =   ( RADIO_MODECNF0_DTX_B0  << RADIO_MODECNF0_DTX_Pos ) |
+                           ( RADIO_MODECNF0_RU_Fast << RADIO_MODECNF0_RU_Pos  );
+    #endif
+
+    NRF_RADIO->FREQUENCY =   ( ( config.frequency & RADIO_FREQUENCY_FREQUENCY_Msk ) << RADIO_FREQUENCY_FREQUENCY_Pos );      // Frequency = 2400 + FREQUENCY (MHz).
+
+
+    // Configure address of the packet and logic address to use
+    NRF_RADIO->PACKETPTR =   (unsigned int)&packet[0]; // Almost the same as (unsigned int)packet,
+                                                     // but sizeof() will return normal pointer size
+
+    // Transmit to address 0
+    NRF_RADIO->TXADDRESS = ( 0 << RADIO_TXADDRESS_TXADDRESS_Pos);
+
+    // Output Power: 0dBm  @2400MHz
+    NRF_RADIO->TXPOWER   =   ( config.tx_power << RADIO_TXPOWER_TXPOWER_Pos );
+                           
+  // TX
+  if (mode == RADIO_MODE_TX) {
+        
+        // Disable receiving address
+        NRF_RADIO->RXADDRESSES = ( RADIO_RXADDRESSES_ADDR0_Disabled << RADIO_RXADDRESSES_ADDR0_Pos );
+
+        // Configure shortcuts.
+        NRF_RADIO->SHORTS    =   ( RADIO_SHORTS_READY_START_Enabled << RADIO_SHORTS_READY_START_Pos ) |
+                                 ( RADIO_SHORTS_END_DISABLE_Enabled << RADIO_SHORTS_END_DISABLE_Pos );
+  }
+  
+    // RX
+    if (mode == RADIO_MODE_RX) {
+        // Use logical address 0 (BASE0 + PREFIX0 byte 0)
+        NRF_RADIO->RXADDRESSES = ( RADIO_RXADDRESSES_ADDR0_Enabled << RADIO_RXADDRESSES_ADDR0_Pos );
+
+        // Configure shortcuts.
+        NRF_RADIO->SHORTS    =   ( RADIO_SHORTS_READY_START_Enabled << RADIO_SHORTS_READY_START_Pos ) |
+                                 ( RADIO_SHORTS_END_START_Enabled << RADIO_SHORTS_END_START_Pos );
+                                 
+        NRF_RADIO->TASKS_RXEN = 1; // Enable receiver
+    }                           
+}
+
+
+void BareRadio::Transmit(char * data) {
+    Transmit((unsigned char *)data);
+}
+void BareRadio::Transmit(unsigned char * data) {
+    // data must be an array of (unsigned) char at least data_len elements wide
+    for (int i=0; i<data_len; i++) packet[i] = data[i];
+    
+    // Transmits one packet
+    NRF_RADIO->TASKS_TXEN                   =    1; // Enable transmitter
+    while ( ( NRF_RADIO->EVENTS_DISABLED )  == 0 ); // Wait until transmission complete
+    NRF_RADIO->EVENTS_DISABLED              =    0; // Clear flag
+    // Time on air: 150 us      
+
+}
+
+int BareRadio::Receive(char * data) {
+    return Receive((unsigned char *) data);
+}
+int BareRadio::Receive(unsigned char * data) {
+    // returns true if a packet has arrived and data was replaced
+    if ( NRF_RADIO->EVENTS_END == 1 ) {
+        NRF_RADIO->EVENTS_END = 0;
+        if (NRF_RADIO->CRCSTATUS) {
+            for (int i=0; i<data_len; i++) data[i] = packet[i];
+            return 1;
+        }
+    }
+    return 0;
+    
+}