Jonathan Jones / Wireless Drivers

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Dependents:   Base Station

CC1101/CC1101-FreqScan.cpp@2:c42a035d71ed, 2014-12-31 (annotated)

Committer:
jjones646
Date:
Wed Dec 31 22:16:01 2014 +0000
Revision:
2:c42a035d71ed
Parent:
1:05a48c038381 
adding dummy cc1101 support

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jjones646 0:c5afea7b9057 1 #include "CC1101.h"
jjones646 0:c5afea7b9057 2
jjones646 0:c5afea7b9057 3 #define CC_NUMBER_OF_SUB_BANDS 1
jjones646 0:c5afea7b9057 4
jjones646 0:c5afea7b9057 5 uint16_t CC1101::scan(void)
jjones646 0:c5afea7b9057 6 {
jjones646 0:c5afea7b9057 7 int8_t i;
jjones646 0:c5afea7b9057 8 int16_t channel;
jjones646 0:c5afea7b9057 9
jjones646 0:c5afea7b9057 10 uint8_t rssi_offset = 74;
jjones646 0:c5afea7b9057 11 carrierSenseCounter = 0;
jjones646 0:c5afea7b9057 12
jjones646 0:c5afea7b9057 13 uint8_t lastChannel = 10;
jjones646 0:c5afea7b9057 14 uint16_t limitTest0Reg = 0;
jjones646 0:c5afea7b9057 15 int16_t highRSSI = -150;
jjones646 0:c5afea7b9057 16 uint16_t selectedChannel = 25;
jjones646 0:c5afea7b9057 17
jjones646 0:c5afea7b9057 18
jjones646 0:c5afea7b9057 19 // Freq. Band Range Channel
jjones646 0:c5afea7b9057 20 // 0 779.009766 - 829.997314 0 - 255 All 0x0B
jjones646 0:c5afea7b9057 21 // 1 830.196869 - 881.184418 0 - 255 <- 154 = 0x0B, 155 -> = 0x09
jjones646 0:c5afea7b9057 22 // 2 881.384369 - 927.972992 0 - 233 All 0x09
jjones646 0:c5afea7b9057 23 /*
jjones646 0:c5afea7b9057 24 uint8_t freqSettings[CC_NUMBER_OF_SUB_BANDS][3] = {{0x1D, 0xF6, 0x40},
jjones646 0:c5afea7b9057 25 {0x1F, 0xEE, 0x3F},
jjones646 0:c5afea7b9057 26 {0x21, 0xE6, 0x3F}
jjones646 0:c5afea7b9057 27 };
jjones646 0:c5afea7b9057 28 */
jjones646 0:c5afea7b9057 29
jjones646 0:c5afea7b9057 30
jjones646 0:c5afea7b9057 31 // 1.1) Set the base freq. for the current sub band. The values for FREQ2, FREQ1, and FREQ0 can be found in
jjones646 0:c5afea7b9057 32 // freqSettings[subBand][n], where n = 0, 1, or 2
jjones646 0:c5afea7b9057 33 /*
jjones646 0:c5afea7b9057 34 for (int n=0; n<3; n++) {
jjones646 0:c5afea7b9057 35 write_reg(CCxxx0_FREQ2 + n, freqSettings[subBand][n]);
jjones646 0:c5afea7b9057 36 }
jjones646 0:c5afea7b9057 37 */
jjones646 0:c5afea7b9057 38
jjones646 0:c5afea7b9057 39 uint8_t calCounter = 0;
jjones646 0:c5afea7b9057 40
jjones646 0:c5afea7b9057 41 // 1.4.2.1) Set TEST0 register = 0x09
jjones646 0:c5afea7b9057 42 write_reg(CCxxx0_TEST0, 0x09);
jjones646 0:c5afea7b9057 43
jjones646 0:c5afea7b9057 44 // 1.4.2.2) Set FSCAL2 register = 0x2A
jjones646 0:c5afea7b9057 45 write_reg(CCxxx0_FSCAL2, 0x2A);
jjones646 0:c5afea7b9057 46
jjones646 0:c5afea7b9057 47
jjones646 0:c5afea7b9057 48 // 1.3) Loop through all channels
jjones646 0:c5afea7b9057 49 for (channel = 0; channel <= lastChannel; channel++ ) {
jjones646 0:c5afea7b9057 50 int8_t pktStatus;
jjones646 0:c5afea7b9057 51
jjones646 0:c5afea7b9057 52 // 1.3.1) Set CHANNR register = channel
jjones646 0:c5afea7b9057 53 write_reg(CCxxx0_CHANNR, channel);
jjones646 0:c5afea7b9057 54
jjones646 0:c5afea7b9057 55 // 1.4.3) Calibrate for every 4th ch. + at start of every sub band and every time the TEST0 reg. is changed
jjones646 0:c5afea7b9057 56 if (calCounter++ == 0) {
jjones646 0:c5afea7b9057 57 // 1.4.3.1) Perform a manual calibration by issuing an SCAL strobe command
jjones646 0:c5afea7b9057 58 calibrate();
jjones646 0:c5afea7b9057 59 }
jjones646 0:c5afea7b9057 60
jjones646 0:c5afea7b9057 61
jjones646 0:c5afea7b9057 62 // 1.4.4)) Reset Calibration Counter (if calCounter = 5, we are 1 MHz away from the frequency where a
jjones646 0:c5afea7b9057 63 // calibration was performed)
jjones646 0:c5afea7b9057 64 if (calCounter == 4) {
jjones646 0:c5afea7b9057 65 // 1.4.4.1) Calibration is performed if calCounter = 0
jjones646 0:c5afea7b9057 66 calCounter = 0;
jjones646 0:c5afea7b9057 67 }
jjones646 0:c5afea7b9057 68
jjones646 0:c5afea7b9057 69
jjones646 0:c5afea7b9057 70 // 1.3.3) Enter RX mode by issuing an SRX strobe command
jjones646 0:c5afea7b9057 71 rx_mode();
jjones646 0:c5afea7b9057 72
jjones646 0:c5afea7b9057 73 // 1.3.4) Wait for radio to enter RX state (can be done by polling the MARCSTATE register)
jjones646 0:c5afea7b9057 74 while(mode() != 0x0D);
jjones646 0:c5afea7b9057 75
jjones646 0:c5afea7b9057 76 // 1.3.5) Wait for RSSI to be valid (See DN505 [7] on how long to wait)
jjones646 0:c5afea7b9057 77 wait(0.4);
jjones646 0:c5afea7b9057 78
jjones646 0:c5afea7b9057 79 // 1.3.6) Read the PKTSTATUS register while the radio is in RX state (store it in pktStatus)
jjones646 0:c5afea7b9057 80 pktStatus = status(CCxxx0_PKTSTATUS);
jjones646 0:c5afea7b9057 81
jjones646 0:c5afea7b9057 82 // 1.3.7) Enter IDLE state by issuing an SIDLE strobe command
jjones646 0:c5afea7b9057 83 strobe(CCxxx0_SIDLE);
jjones646 0:c5afea7b9057 84
jjones646 0:c5afea7b9057 85 // 1.3.8) Check if CS is asserted (use the value obtained in 1.3.6)
jjones646 0:c5afea7b9057 86 if (pktStatus & 0x40) { // CS is asserted
jjones646 0:c5afea7b9057 87
jjones646 0:c5afea7b9057 88 // 1.3.8.1) Read RSSI value and store it in rssi_dec
jjones646 0:c5afea7b9057 89 rssi_dec = status(CCxxx0_RSSI);
jjones646 0:c5afea7b9057 90
jjones646 0:c5afea7b9057 91 // 1.3.8.2) Calculate RSSI in dBm (rssi_dBm)(offset value found in rssi_offset)
jjones646 0:c5afea7b9057 92 if (rssi_dec & 0x80) {
jjones646 0:c5afea7b9057 93 rssi_dBm = (rssi_dec - 256)>>1; // negate and divide by 2
jjones646 0:c5afea7b9057 94 } else {
jjones646 0:c5afea7b9057 95 rssi_dBm = rssi_dec>>1; // divide by 2
jjones646 0:c5afea7b9057 96 }
jjones646 0:c5afea7b9057 97 rssi_dBm -= rssi_offset; // offset adjustment
jjones646 0:c5afea7b9057 98
jjones646 0:c5afea7b9057 99
jjones646 0:c5afea7b9057 100 std::printf("RSSI: %d\r\n", rssi_dBm);
jjones646 0:c5afea7b9057 101 // 1.3.8.3) Store the RSSI value and the corresponding channel number
jjones646 0:c5afea7b9057 102 rssiTable[carrierSenseCounter] = rssi_dBm;
jjones646 0:c5afea7b9057 103 channelNumber[carrierSenseCounter] = channel;
jjones646 0:c5afea7b9057 104 carrierSenseCounter++;
jjones646 0:c5afea7b9057 105 }
jjones646 0:c5afea7b9057 106 } // End Channel Loop
jjones646 0:c5afea7b9057 107
jjones646 0:c5afea7b9057 108
jjones646 0:c5afea7b9057 109 // 1.4) Before moving on to the next sub band, scan through the rssiTable to find the highest RSSI value. Store
jjones646 0:c5afea7b9057 110 // the RSSI value in highRSSI and the corresponding channel number in selectedChannel
jjones646 0:c5afea7b9057 111 for (i = 0; i < carrierSenseCounter; i++) {
jjones646 0:c5afea7b9057 112 if (rssiTable[i] > highRSSI) {
jjones646 0:c5afea7b9057 113 highRSSI = rssiTable[i];
jjones646 0:c5afea7b9057 114 selectedChannel = channelNumber[i];
jjones646 0:c5afea7b9057 115 }
jjones646 0:c5afea7b9057 116 }
jjones646 0:c5afea7b9057 117
jjones646 0:c5afea7b9057 118
jjones646 0:c5afea7b9057 119 // 1.5) Reset carrierSenseCounter
jjones646 0:c5afea7b9057 120 // carrierSenseCounter = 0;
jjones646 0:c5afea7b9057 121
jjones646 0:c5afea7b9057 122 // } // End Band Loop
jjones646 0:c5afea7b9057 123
jjones646 0:c5afea7b9057 124 /*
jjones646 0:c5afea7b9057 125
jjones646 0:c5afea7b9057 126 // 2) When all sub bands have been scanned, find which sub band has the highest RSSI (Scan the highRSSI[subBand]
jjones646 0:c5afea7b9057 127 // table). Store the subBand (0, 1, or 2) and the corresponding channel in the global variables activeBand and
jjones646 0:c5afea7b9057 128 // activeChannel respectively
jjones646 0:c5afea7b9057 129 int16_t tempRssi = -150;
jjones646 0:c5afea7b9057 130 // for (int subBand = 0; subBand < CC_NUMBER_OF_SUB_BANDS; subBand++)
jjones646 0:c5afea7b9057 131 // {
jjones646 0:c5afea7b9057 132 if (highRSSI >= tempRssi) {
jjones646 0:c5afea7b9057 133 tempRssi = highRSSI;
jjones646 0:c5afea7b9057 134 activeChannel = selectedChannel;
jjones646 0:c5afea7b9057 135 activeBand = subBand;
jjones646 0:c5afea7b9057 136 }
jjones646 0:c5afea7b9057 137 // }
jjones646 0:c5afea7b9057 138
jjones646 0:c5afea7b9057 139 */
jjones646 0:c5afea7b9057 140
jjones646 0:c5afea7b9057 141 activeChannel = selectedChannel;
jjones646 0:c5afea7b9057 142
jjones646 0:c5afea7b9057 143 std::printf("Active Channel: %u\r\nRSSI: %ddBm\r\n", activeChannel, highRSSI);
jjones646 0:c5afea7b9057 144
jjones646 0:c5afea7b9057 145 return activeChannel;
jjones646 0:c5afea7b9057 146
jjones646 0:c5afea7b9057 147 }