add basic nRF24 driver

1 files changed, 95 insertions, 0 deletions

diff --git a/src/driver/nrf24l01.cc b/src/driver/nrf24l01.cc
new file mode 100644
index 0000000..144158c
--- /dev/null
+++ b/src/driver/nrf24l01.cc
@@ -0,0 +1,95 @@
+/*
+ * Based on https://github.com/nRF24/RF24
+ */
+
+#include <stdlib.h>
+
+#include "driver/nrf24l01.h"
+#include "driver/nrf24l01/registers.h"
+#include "driver/spi_b.h"
+#include "driver/gpio.h"
+#include "arch.h"
+
+#ifndef NRF24L01_EN_PIN
+#error makeflag nrf24l01_en_pin required
+#endif
+
+#ifndef NRF24L01_CS_PIN
+#error makeflag nrf24l01_cs_pin required
+#endif
+
+void Nrf24l01::setup()
+{
+	spi.setup();
+	gpio.output(NRF24L01_EN_PIN);
+	gpio.output(NRF24L01_CS_PIN);
+	gpio.write(NRF24L01_EN_PIN, 0);
+	csnHigh();
+	arch.delay_ms(5);
+
+	// Reset NRF_CONFIG and enable 16-bit CRC.
+	writeRegister( NRF_CONFIG, 0b00001100 ) ;
+
+	// Set 1500uS (minimum for 32B payload in ESB@250KBPS) timeouts, to make testing a little easier
+	// WARNING: If this is ever lowered, either 250KBS mode with AA is broken or maximum packet
+	// sizes must never be used. See documentation for a more complete explanation.
+	setRetries(5,15);
+
+	// Reset value is MAX
+	setPALevel( RF24_PA_MAX ) ;
+
+}
+
+void Nrf24l01::setRetries(uint8_t delay, uint8_t count)
+{
+	writeRegister(SETUP_RETR,(delay&0xf)<<ARD | (count&0xf)<<ARC);
+}
+
+void Nrf24l01::setPALevel(uint8_t level)
+{
+	uint8_t setup = readRegister(RF_SETUP) & 0b11111000;
+
+	if(level > 3){  						// If invalid level, go to max PA
+		level = (RF24_PA_MAX << 1) + 1;		// +1 to support the SI24R1 chip extra bit
+	}else{
+		level = (level << 1) + 1;	 		// Else set level as requested
+	}
+
+	writeRegister( RF_SETUP, setup |= level ) ;	// Write it to the chip
+}
+
+uint8_t Nrf24l01::getStatus()
+{
+	txbuf[0] = NOP;
+	beginTransaction();
+	spi.xmit(1, txbuf, 1, rxbuf);
+	endTransaction();
+
+	return rxbuf[0];
+}
+
+uint8_t Nrf24l01::readRegister(uint8_t reg)
+{
+	txbuf[0] = R_REGISTER | ( REGISTER_MASK & reg );
+	txbuf[1] = NOP;
+
+	beginTransaction();
+	spi.xmit(2, txbuf, 2, rxbuf);
+	endTransaction();
+
+	return rxbuf[1];
+}
+
+uint8_t Nrf24l01::writeRegister(uint8_t reg, uint8_t value)
+{
+	txbuf[0] = W_REGISTER | (REGISTER_MASK & reg);
+	txbuf[1] = value;
+
+	beginTransaction();
+	spi.xmit(2, txbuf, 1, rxbuf);
+	endTransaction();
+
+	return rxbuf[0];
+}
+
+Nrf24l01 nrf24l01;