For robots and stuff
Diff: Wireless/CC1101/CC1101-FreqScan.cpp
- Revision:
- 0:c5afea7b9057
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Wireless/CC1101/CC1101-FreqScan.cpp Sun Dec 28 06:27:18 2014 +0000 @@ -0,0 +1,147 @@ +#include "CC1101.h" + +#define CC_NUMBER_OF_SUB_BANDS 1 + +uint16_t CC1101::scan(void) +{ + int8_t i; + int16_t channel; + + uint8_t rssi_offset = 74; + carrierSenseCounter = 0; + + uint8_t lastChannel = 10; + uint16_t limitTest0Reg = 0; + int16_t highRSSI = -150; + uint16_t selectedChannel = 25; + + +// Freq. Band Range Channel +// 0 779.009766 - 829.997314 0 - 255 All 0x0B +// 1 830.196869 - 881.184418 0 - 255 <- 154 = 0x0B, 155 -> = 0x09 +// 2 881.384369 - 927.972992 0 - 233 All 0x09 + /* + uint8_t freqSettings[CC_NUMBER_OF_SUB_BANDS][3] = {{0x1D, 0xF6, 0x40}, + {0x1F, 0xEE, 0x3F}, + {0x21, 0xE6, 0x3F} + }; + */ + + +// 1.1) Set the base freq. for the current sub band. The values for FREQ2, FREQ1, and FREQ0 can be found in +// freqSettings[subBand][n], where n = 0, 1, or 2 + /* + for (int n=0; n<3; n++) { + write_reg(CCxxx0_FREQ2 + n, freqSettings[subBand][n]); + } + */ + + uint8_t calCounter = 0; + + // 1.4.2.1) Set TEST0 register = 0x09 + write_reg(CCxxx0_TEST0, 0x09); + + // 1.4.2.2) Set FSCAL2 register = 0x2A + write_reg(CCxxx0_FSCAL2, 0x2A); + + + // 1.3) Loop through all channels + for (channel = 0; channel <= lastChannel; channel++ ) { + int8_t pktStatus; + + // 1.3.1) Set CHANNR register = channel + write_reg(CCxxx0_CHANNR, channel); + + // 1.4.3) Calibrate for every 4th ch. + at start of every sub band and every time the TEST0 reg. is changed + if (calCounter++ == 0) { + // 1.4.3.1) Perform a manual calibration by issuing an SCAL strobe command + calibrate(); + } + + + // 1.4.4)) Reset Calibration Counter (if calCounter = 5, we are 1 MHz away from the frequency where a + // calibration was performed) + if (calCounter == 4) { + // 1.4.4.1) Calibration is performed if calCounter = 0 + calCounter = 0; + } + + + // 1.3.3) Enter RX mode by issuing an SRX strobe command + rx_mode(); + + // 1.3.4) Wait for radio to enter RX state (can be done by polling the MARCSTATE register) + while(mode() != 0x0D); + + // 1.3.5) Wait for RSSI to be valid (See DN505 [7] on how long to wait) + wait(0.4); + + // 1.3.6) Read the PKTSTATUS register while the radio is in RX state (store it in pktStatus) + pktStatus = status(CCxxx0_PKTSTATUS); + + // 1.3.7) Enter IDLE state by issuing an SIDLE strobe command + strobe(CCxxx0_SIDLE); + + // 1.3.8) Check if CS is asserted (use the value obtained in 1.3.6) + if (pktStatus & 0x40) { // CS is asserted + + // 1.3.8.1) Read RSSI value and store it in rssi_dec + rssi_dec = status(CCxxx0_RSSI); + + // 1.3.8.2) Calculate RSSI in dBm (rssi_dBm)(offset value found in rssi_offset) + if (rssi_dec & 0x80) { + rssi_dBm = (rssi_dec - 256)>>1; // negate and divide by 2 + } else { + rssi_dBm = rssi_dec>>1; // divide by 2 + } + rssi_dBm -= rssi_offset; // offset adjustment + + + std::printf("RSSI: %d\r\n", rssi_dBm); + // 1.3.8.3) Store the RSSI value and the corresponding channel number + rssiTable[carrierSenseCounter] = rssi_dBm; + channelNumber[carrierSenseCounter] = channel; + carrierSenseCounter++; + } + } // End Channel Loop + + + // 1.4) Before moving on to the next sub band, scan through the rssiTable to find the highest RSSI value. Store + // the RSSI value in highRSSI and the corresponding channel number in selectedChannel + for (i = 0; i < carrierSenseCounter; i++) { + if (rssiTable[i] > highRSSI) { + highRSSI = rssiTable[i]; + selectedChannel = channelNumber[i]; + } + } + + + // 1.5) Reset carrierSenseCounter + // carrierSenseCounter = 0; + +// } // End Band Loop + + /* + + // 2) When all sub bands have been scanned, find which sub band has the highest RSSI (Scan the highRSSI[subBand] + // table). Store the subBand (0, 1, or 2) and the corresponding channel in the global variables activeBand and + // activeChannel respectively + int16_t tempRssi = -150; + // for (int subBand = 0; subBand < CC_NUMBER_OF_SUB_BANDS; subBand++) + // { + if (highRSSI >= tempRssi) { + tempRssi = highRSSI; + activeChannel = selectedChannel; + activeBand = subBand; + } + // } + + */ + + activeChannel = selectedChannel; + + std::printf("Active Channel: %u\r\nRSSI: %ddBm\r\n", activeChannel, highRSSI); + + return activeChannel; + +} \ No newline at end of file