examples: Raw nrf51822 observerraw-examples

2 files changed, 254 insertions, 0 deletions

diff --git a/examples/nrf51822/raw-observer/Makefile b/examples/nrf51822/raw-observer/Makefile
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+++ b/examples/nrf51822/raw-observer/Makefile
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+# Makefile for nrf51822 raw-observer example
+
+PROJECT_TARGET		= raw-observer-example
+PROJECT_SOURCE_FILES	= main.c
+
+BLESTACK_PATH		= ../../..
+-include $(BLESTACK_PATH)/Makefile.common
diff --git a/examples/nrf51822/raw-observer/main.c b/examples/nrf51822/raw-observer/main.c
new file mode 100644
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+++ b/examples/nrf51822/raw-observer/main.c
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+/**
+ *  The MIT License (MIT)
+ *
+ *  Copyright (c) 2013 Paulo B. de Oliveira Filho <pauloborgesfilho@gmail.com>
+ *  Copyright (c) 2013 Claudio Takahasi <claudio.takahasi@gmail.com>
+ *  Copyright (c) 2013 João Paulo Rechi Vita <jprvita@gmail.com>
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "nrf51.h"
+#include "nrf_delay.h"
+
+#include "log.h"
+
+#define SET_BIT(n)	(1UL << n)
+#define MAX_PDU_SIZE	(64UL)
+
+#define ADV_CHANNEL_37	(2UL)		/* 2402 MHz */
+#define ADV_CHANNEL_38	(26UL)		/* 2426 MHz */
+#define ADV_CHANNEL_39	(80UL)		/* 2480 MHz */
+
+#define MS(s)		(1000 * s)
+#define RTC_PERIOD	(5)		/* ms */
+#define RTC_PRESCALER	(((32768 * RTC_PERIOD) / 1000) - 1)
+#define SCAN_WINDOW	(MS(1) / RTC_PERIOD)
+#define SCAN_INTERVAL	(MS(2) / RTC_PERIOD)
+
+static __inline void start_hfclk(void)
+{
+	NRF_CLOCK->EVENTS_HFCLKSTARTED = 0UL;
+	NRF_CLOCK->TASKS_HFCLKSTART = 1UL;
+	while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0UL);
+}
+
+static __inline void start_lfclk(void)
+{
+	NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_Xtal
+						<< CLOCK_LFCLKSRC_SRC_Pos;
+	NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
+	NRF_CLOCK->TASKS_LFCLKSTART = 1;
+	while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);
+}
+
+static __inline void start_rtc0(void)
+{
+	NRF_RTC0->PRESCALER = RTC_PRESCALER;
+	NRF_RTC0->TASKS_START = 1UL;
+}
+
+static __inline void dbg_packet(uint8_t channel, const uint8_t *pdu)
+{
+	uint8_t f = pdu[1] + 3;
+	uint8_t i;
+
+	log_print("Advertising channel %u\r\n", channel);
+	log_print("CRC:      %s\r\n", (NRF_RADIO->CRCSTATUS == 1) ?
+								"OK" : "FAIL");
+	log_print("PDU Type: 0x%02x\r\n", (pdu[0] >> 4) & 0xF);
+	log_print("TxAdd:    %u\r\n", (pdu[0] >> 1) & 0x1);
+	log_print("RxAdd:    %u\r\n", pdu[0] & 0x1);
+	log_print("Length:   %u\r\n", pdu[1] & 0x3F);
+
+	log_print("Payload:  ");
+
+	for (i = 3; i < f; i++) {
+		log_print("0x%02X ", pdu[i]);
+	}
+
+	log_print("\r\n"); 
+}
+
+static __inline void scan_channel(uint8_t channel, uint8_t frequency,
+					uint32_t window, const uint8_t *pdu)
+{
+	NRF_RADIO->FREQUENCY = frequency;
+	NRF_RADIO->DATAWHITEIV = channel & 0x3F;
+
+	NRF_RADIO->EVENTS_READY = 0UL;
+	NRF_RADIO->TASKS_RXEN = 1UL;
+	while (NRF_RADIO->EVENTS_READY == 0UL);
+
+	NRF_RADIO->EVENTS_END = 0UL;
+	NRF_RADIO->TASKS_START = 1UL;
+	while (NRF_RADIO->EVENTS_END == 0UL &&
+				(NRF_RTC0->COUNTER - window < SCAN_WINDOW));
+
+	NRF_RADIO->EVENTS_DISABLED = 0UL;
+	NRF_RADIO->TASKS_DISABLE = 1UL;
+	while (NRF_RADIO->EVENTS_DISABLED == 0UL);
+
+	if (NRF_RADIO->EVENTS_END == 1UL)
+		dbg_packet(channel, pdu);
+}
+
+static __inline void wait_scan_interval(uint32_t start)
+{
+	uint32_t tmp;
+
+	tmp = SCAN_INTERVAL - RTC_PERIOD * (NRF_RTC0->COUNTER - start);
+
+	if (tmp <= SCAN_INTERVAL)
+		nrf_delay_ms(tmp);
+}
+
+#define START_TIMER(t) do { t = NRF_RTC0->COUNTER; } while(0)
+
+static uint8_t pdu[MAX_PDU_SIZE];
+static volatile uint32_t timer;
+
+static void __inline setup(void)
+{
+	/* Start UART logging module. */
+	log_init();
+
+	/* Start high frequency clock (16 MHz). */
+	start_hfclk();
+
+	/* Start low frequency clock (32.768 kHz). */
+	start_lfclk();
+
+	/* Start Real Timer Counter 0 (RTC0). */
+	start_rtc0();
+
+	/* Start to configure the RADIO.
+	*
+	* We clear PCNF0 and CPNF1 registers to use OR operations in the next
+	* operations.
+	*/
+	NRF_RADIO->PCNF0 = 0UL;
+	NRF_RADIO->PCNF1 = 0UL;
+
+	/* Set RADIO mode to Bluetooth Low Energy. */
+	NRF_RADIO->MODE = RADIO_MODE_MODE_Ble_1Mbit << RADIO_MODE_MODE_Pos;
+
+	/* Set transmission power to 0dBm. */
+	NRF_RADIO->TXPOWER = RADIO_TXPOWER_TXPOWER_0dBm
+						<< RADIO_TXPOWER_TXPOWER_Pos;
+
+	/* Set access address to 0x8E89BED6. This is the access address to be
+	* used when send packets in advertise channels.
+	*
+	* Since the access address is 4 bytes long and the prefix is 1 byte
+	* long, we first set the base address length to be 3 bytes long.
+	*
+	* Then we split the full access address in:
+	* 1. Prefix0:  0x0000008E (LSB -> Logic address 0)
+	* 2. Base0:    0x89BED600 (3 MSB)
+	*
+	* At last, we enable reception for this address.
+	*/
+	NRF_RADIO->PCNF1	|= 3UL << RADIO_PCNF1_BALEN_Pos;
+	NRF_RADIO->BASE0	= 0x89BED600;
+	NRF_RADIO->PREFIX0	= 0x0000008E;
+	NRF_RADIO->RXADDRESSES	= 0x00000001;
+
+	/* Enable data whitening. */
+	NRF_RADIO->PCNF1 |= RADIO_PCNF1_WHITEEN_Enabled
+						<< RADIO_PCNF1_WHITEEN_Pos;
+
+	/* Set maximum PAYLOAD size. */
+	NRF_RADIO->PCNF1 |= MAX_PDU_SIZE << RADIO_PCNF1_MAXLEN_Pos;
+
+	/* Configure CRC.
+	*
+	* First, we set the length of CRC field to 3 bytes long and ignore the
+	* access address in the CRC calculation.
+	*
+	* Then we set CRC initial value to 0x555555.
+	*
+	* The last step is to set the CRC polynomial to
+	* x^24 + x^10 + x^9 + x^6 + x^4 + x^3 + x + 1.
+	*/
+	NRF_RADIO->CRCCNF = (RADIO_CRCCNF_LEN_Three << RADIO_CRCCNF_LEN_Pos) |
+		(RADIO_CRCCNF_SKIP_ADDR_Skip << RADIO_CRCCNF_SKIP_ADDR_Pos);
+
+	NRF_RADIO->CRCINIT = 0x555555UL;
+
+	NRF_RADIO->CRCPOLY = SET_BIT(24) | SET_BIT(10) | SET_BIT(9) |
+				SET_BIT(6) | SET_BIT(4) | SET_BIT(3) |
+				SET_BIT(1) | SET_BIT(0);
+
+	/* Configure header size.
+	*
+	* The Advertise has the following format:
+	* PDU Type(4b) | RFU(2b) | TxAdd(1b) | RxAdd(1b) | Length(6b) | RFU(2b)
+	*
+	* And the nRF51822 RADIO packet has the following format
+	* (directly editable fields):
+	* S0 (0/1 bytes) | LENGTH ([0, 8] bits) | S1 ([0, 8] bits)
+	*
+	* We can match those fields with the Link Layer fields:
+	* S0 (1 byte)     -> PDU Type(4bits)|RFU(2bits)|TxAdd(1bit)|RxAdd(1bit)
+	* LENGTH (6 bits) -> Length(6bits)
+	* S1 (2 bits)     -> S1(2bits)
+	*/
+	NRF_RADIO->PCNF0 |=	(1 << RADIO_PCNF0_S0LEN_Pos) |  /* 1 byte */
+				(6 << RADIO_PCNF0_LFLEN_Pos) |  /* 6 bits */
+				(2 << RADIO_PCNF0_S1LEN_Pos);   /* 2 bits */
+
+	/* Set the pointer to write the incoming packet. */
+	NRF_RADIO->PACKETPTR = (uint32_t) pdu;
+	memset(pdu, 0, sizeof(pdu));
+}
+
+int main(void)
+{
+	setup();
+
+	while (1) {
+		log_print("Scanning with wnd: %u ticks, interval: %u ticks\r\n",
+						SCAN_WINDOW, SCAN_INTERVAL);
+
+		/* Advertising channel 37 */
+		START_TIMER(timer);
+		scan_channel(37, ADV_CHANNEL_37, timer, pdu);
+		wait_scan_interval(timer);
+
+		/* Advertising channel 38 */
+		START_TIMER(timer);
+		scan_channel(38, ADV_CHANNEL_38, timer, pdu);
+		wait_scan_interval(timer);
+
+		/* Advertising channel 39 */
+		START_TIMER(timer);
+		scan_channel(39, ADV_CHANNEL_39, timer, pdu);
+		wait_scan_interval(timer);
+	}
+}