The pin definitions are updated and the uart debug interface is removed
as it is not present on the actual board.

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "weather-sensor/firmware/BME280_driver"]
+	path = weather-sensor/firmware/BME280_driver
+	url = https://github.com/BoschSensortec/BME280_driver.git

weather-sensor/firmware/.gitignore

@@ -0,0 +1,5 @@
+main
+*.hex
+
+
+*.swp

weather-sensor/firmware/BME280_driver

@@ -0,0 +1 @@
+Subproject commit 3d686a326565b9cadb8507f73d7576ec0cc891f2

weather-sensor/firmware/bme280_interface.c

@@ -0,0 +1,112 @@
+#include <avr/io.h>
+#include <util/delay.h>
+
+#include "spi.h"
+#include "bme280.h"
+#include "bme280_interface.h"
+
+
+void user_delay_ms(uint32_t period);
+int8_t user_spi_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len);
+int8_t user_spi_write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len);
+
+
+struct bme280_dev deviceStructure;
+uint32_t req_delay;
+
+
+int8_t Initialize_BME280(void)
+{
+	int8_t rslt = BME280_OK;
+	uint8_t settings_sel;
+
+
+	Set_BME280_Pins();
+
+	/* Sensor_0 interface over SPI with native chip select line */
+	deviceStructure.dev_id = 0;
+	deviceStructure.intf = BME280_SPI_INTF;
+	deviceStructure.read = user_spi_read;
+	deviceStructure.write = user_spi_write;
+	deviceStructure.delay_ms = user_delay_ms;
+
+	rslt = bme280_init(&deviceStructure);
+
+	/* Settings for mode of operation: weather monitorint */
+	deviceStructure.settings.osr_h = BME280_OVERSAMPLING_1X;
+	deviceStructure.settings.osr_p = BME280_OVERSAMPLING_1X;
+	deviceStructure.settings.osr_t = BME280_OVERSAMPLING_1X;
+	deviceStructure.settings.filter = BME280_FILTER_COEFF_OFF;
+
+	settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;
+
+	rslt = bme280_set_sensor_settings(settings_sel, &deviceStructure);
+
+	/* calculate minimum delay required between consecutive measurments */
+	req_delay = bme280_cal_meas_delay(&deviceStructure.settings);
+
+	return rslt;
+}
+
+void Set_BME280_Pins(void)
+{
+	/* Setup the SPI interface */
+	BME_CSN_DDR |= (1 << BME_CSN_PIN);
+	BME_CSN_PORT |= (1 << BME_CSN_PIN);
+}
+
+/* Get one measurement in forced mode */
+void BME280_Get_Measurement(struct bme280_data * data)
+{
+	bme280_set_sensor_mode(BME280_FORCED_MODE, &deviceStructure);
+	deviceStructure.delay_ms(req_delay);
+	bme280_get_sensor_data(BME280_ALL, data, &deviceStructure);
+}
+
+/* Implementation of the interface function needed by the BME280 library */
+void user_delay_ms(uint32_t period)
+{
+	while (period--)
+	{
+		_delay_ms(1);
+	}
+}
+
+int8_t user_spi_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
+{
+	int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
+
+	/* unused parameters */
+	(void)dev_id;
+
+	SPI_Start_Transmission(&BME_CSN_PORT, BME_CSN_PIN);
+	SPI_Transfer_Byte(reg_addr);
+
+	for (uint16_t i = 0; i < len; i ++)
+	{
+		reg_data[i] = SPI_Transfer_Byte(0x0); /* Value to send doesn't matter */
+	}
+	SPI_Stop_Transmission(&BME_CSN_PORT, BME_CSN_PIN);
+
+	return rslt;
+}
+
+int8_t user_spi_write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
+{
+	int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
+
+	/* unused parameters */
+	(void)dev_id;
+
+	/* SPI routine */
+	SPI_Start_Transmission(&BME_CSN_PORT, BME_CSN_PIN);
+	SPI_Transfer_Byte(reg_addr);
+
+	for (uint16_t i = 0; i < len; i ++)
+	{
+		SPI_Transfer_Byte(reg_data[i]);
+	}
+	SPI_Stop_Transmission(&BME_CSN_PORT, BME_CSN_PIN);
+
+	return rslt;
+}

weather-sensor/firmware/bme280_interface.h

@@ -0,0 +1,16 @@
+#ifndef BME280_H
+#define BME280_H
+
+#include <stdint.h>
+#include "bme280_defs.h"
+
+/* AVR I/O pin definionts */
+#define BME_CSN_DDR   DDRB
+#define BME_CSN_PORT  PORTB
+#define BME_CSN_PIN   PB2
+
+int8_t Initialize_BME280(void);
+void Set_BME280_Pins(void);
+void BME280_Get_Measurement(struct bme280_data * data);
+
+#endif

weather-sensor/firmware/compile.sh

@@ -0,0 +1,2 @@
+make main
+make main.hex

weather-sensor/firmware/main.c

@@ -0,0 +1,188 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <util/delay.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "spi.h"
+#include "nrf24l01.h"
+#include "nrf24l01_definitions.h"
+#include "bme280_interface.h"
+#include "bme280_defs.h"
+
+
+
+/* Debug LED: */
+#define LED_DDR   DDRD
+#define LED_PORT  PORTD
+#define LED_PIN   PD3
+
+
+char bool_case = 0;
+int timer = 0;
+int timer_max = 0;
+
+volatile uint8_t cycle = 0;
+
+volatile uint8_t interruptCounter;
+volatile uint8_t executionFlag;
+
+
+void Enter_Power_Save_Mode(void);
+void Exit_Power_Save_Mode(void);
+
+
+/* TODO Notes for power saving:
+ * - Power-save-mode needed -> SM2...0 bits written to 011
+ * - Entering by issuing the SLEEP instruction -> What call in C?
+ *   - Before executing the SLEEP instruction, write bit SE of the SMCR to 1
+ * - Let Timer/Counter2 run with the necessary period and enable an interrupt.
+ *   -> The Global Interrupt Enable bit in SREG has to be set.
+ * - asynchronous/synchronous clock source?
+ * - When waking up
+ *   - Set PRR bits for needed peripherals
+ * - 
+ */
+void Set_Up_Power_Save_Mode(void);
+void Enter_Power_Save_Mode(void);
+
+
+ISR( TIMER2_COMPA_vect )
+{
+	/* Do nothing as the interrupt is only used to wake up the MCU. */
+}
+
+int main (void)
+{
+	struct bme280_data sensorData;
+//	uint8_t testRegisterContent = 0x0A;
+//	uint8_t registerContent[5];
+//	char registerContentString[30];
+//	uint8_t lengthRead;
+	uint8_t temp = 0;
+
+	/* Enable the debug LED */
+	LED_DDR |= (1 << LED_PIN);
+
+	/* Initialize the SPI */
+	Initialize_SPI();
+
+	/* Initialize the nrf24l01 */
+	Initialize_NRF24L01();
+	// The NRF24L01 is now in the mode Standby-I.
+
+	/* Configure the transmission parameters (Enhanced ShockBurst)*/
+	Configure_Transmission();
+
+	/* Initialize the BME280 */
+	Initialize_BME280();
+	Set_Up_Power_Save_Mode();
+
+
+	/* Delay the change of the operating frequency by the function Enter_Power_Save_Mode for the
+	 * first function pass. If it is changed before the ISP can flash the MCU the clocks of the ISP
+	 * and MCU are mismatched and the flashing will fail.
+	 */
+	_delay_ms(500);
+
+	while(1)
+	{
+		Enter_Power_Save_Mode(); // The MCU enters the Power Save Mode here.
+		Exit_Power_Save_Mode(); // The MCU exits the Power Save Mode here.
+
+		if (cycle == 0) // TODO cycle == 7 to execute this every 60 s
+		{
+			/* Re-Initialize the peripherals */
+			Set_BME280_Pins();
+			Set_NRF24L01_Pins();
+
+			/* Get measurement and send it */
+			BME280_Get_Measurement(&sensorData);
+			NRF24L01_Send_Message((uint8_t*)&sensorData, sizeof(sensorData));
+
+			if (temp == 0)
+			{
+				LED_PORT |= (1 << LED_PIN);
+				temp = 1;
+			}
+			else
+			{
+				temp = 0;
+				LED_PORT &= ~(1 << LED_PIN);
+			}
+
+			cycle = 0;
+		}
+		else
+		{
+			cycle ++;
+		}
+	}
+}
+
+void Set_Up_Power_Save_Mode(void)
+{
+	// Disable Brown-Out-Detection by setting the BODLEVEL 2:0 Fuses to 0b111 (should be default)
+	// Disable the on-chip debug system by setting the DWEN Fuse to 1 (should be default)
+
+	/* Disable some unused peripherals that are not used during operation of the weather station: */
+	// The ADC is turned off by default
+	ACSR &= ~(1<<ACD); // Analog comperator
+	ACSR &= ~(1<<ACIE); // The interrupt bit has to be cleared after switchin of the analog comperator
+	/*
+	 * The Internal voltager reference is automatically disabled if the BOD, ADC and Voltage
+	 * Reference are disabled
+	 */
+
+	/* Set up Timer/Counter2 */
+	PRR &= ~(1<<PRTIM2); // Enable the timer 2 in the Power Reduction Register
+
+	TCCR2A |= (1<<COM2A1)|(1<<COM2A0)|(1<<WGM21); // Set the timer to ClearTimer on Compare Match with output compare mode for channel A
+	/* There is a problem: The maximum time until the counter 2 overflows is 262ms at the nominal
+	 * core frquency of 1MHz and a timer prescaler of 1024.
+	 * This can be attenuated by lowering the system frequency to 31.25 kHz via the clock prescaler
+	 * (CLKPS3...0) of the register CLKPR. This gives a overflow time of 8.3s.
+	 * The cycle time of one minute can thus be accomplished by setting the output compare register
+	 * to 229. This spawns an interrupt every 7.5s which means the operation has to be executed
+	 * every 8 interrupt calls.
+	 */
+
+	TCCR2B |= (1<<CS22)|(1<<CS21)|(1<<CS20); // Set the timer prescaler to 1/1024
+	OCR2A = 229; // TODO: calculate this number from the wanted cycle time and the timer frequency.
+
+	TIMSK2 |= (1<<OCIE2A); // Enable the Output Compare Match A Interrupt.
+
+	/* Enable global interrupts: */
+	sei();
+}
+
+void Enter_Power_Save_Mode(void)
+{
+	PRR |= (1<<PRTWI) | (1<<PRTIM0) | (1<<PRTIM1) | (1<<PRSPI) | (1<<PRUSART0) | (1<<PRADC); /* Only timer 2 is needed for wake-up interrupt */
+
+	/* Set the clock prescaler for a frequency of 32.25 kHz*/
+	CLKPR = (1<<CLKPCE);
+	CLKPR = (1<<CLKPS3);
+
+	TCNT2 = 0;// Reset timer 2
+	TIMSK2 |= (1<<OCIE2A); // Enable the Output Compare Match A Interrupt.
+
+
+	set_sleep_mode(SLEEP_MODE_PWR_SAVE);
+	sleep_mode();
+}
+
+void Exit_Power_Save_Mode(void)
+{
+	TIMSK2 &= ~(1<<OCIE2A); // Disable the Output Compare Match A Interrupt.
+
+	/* Set the normal operating frequency of 1 MHz */
+	CLKPR = (1<<CLKPCE);
+	CLKPR = (1<<CLKPS1) | (1<<CLKPS0);
+
+	PRR &= ~(1<<PRSPI); // Enable SPI
+	Initialize_SPI(); // reinitalize SPI
+}

weather-sensor/firmware/main.hex

@@ -1,200 +0,0 @@
-:100000000C9456000C9473000C9473000C947300C1
-:100010000C9473000C9473000C9473000C94730094
-:100020000C9473000C9473000C9473000C94730084
-:100030000C9473000C9473000C9473000C94730074
-:100040000C9473000C9473000C9473000C94730064
-:100050000C9473000C9473000C9473000C94730054
-:100060000C9473000C9473000C9473000C94730044
-:100070000C9473000C9473000C9473000C94730034
-:100080000C9473000C9473000C9473000C94730024
-:100090000C9473000C9473000C9473000C94730014
-:1000A0000C9473000C9473000C94730011241FBE05
-:1000B000CFEFDAE0DEBFCDBF11E0A0E0B1E0E6E1D6
-:1000C000FCE002C005900D92AE34B107D9F721E0F3
-:1000D000AEE4B1E001C01D92A335B207E1F70E9482
-:1000E000C5020C9409060C94000086E084B980E5F2
-:1000F0008CBD08952D988FEF8EBD0DB407FEFDCFFA
-:100100002D9A8EB50895982F86EF890F823010F0C2
-:10011000903111F485E001C081E02D989EBD0DB4B1
-:1001200007FEFDCF262FFB011EBC0DB407FEFDCF41
-:100130009EB591939E2F921B9817B0F32D9A089518
-:100140009F92AF92BF92CF92DF92EF92FF920F9366
-:100150001F93CF93DF93CDB7DEB7C555D1090FB647
-:10016000F894DEBF0FBECDBF1A821982FE0133960E
-:1001700090E3DF011D929A95E9F77E01B1E5EB0E60
-:10018000F11CB7010E948300982E1BAA67018E0103
-:100190000D5C1F4F84E2A82E81E0B82E8C2D8E19A5
-:1001A000891598F4F60181916F011F928F931F9327
-:1001B0000F93BF92AF921F930F930E941F030FB62E
-:1001C000F894DEBF0FBECDBFE9CF1F930F9382E13E
-:1001D00091E09F938F938E010F5F1F4F1F930F939B
-:1001E0000E941F03C8010E94AB020F900F900F9056
-:1001F0000F900F900F90CB5ADF4F0FB6F894DEBFE1
-:100200000FBECDBFDF91CF911F910F91FF90EF9067
-:10021000DF90CF90BF90AF909F9008952D9880620F
-:100220008EBD0DB407FEFDCF6EBD0DB407FEFDCF34
-:100230002D9A0895249A259A2D9A2C988FEE95E55B
-:100240000197F1F700C000006AE080E00E940E0113
-:100250008FE99FE00197F1F700C0000008952D9805
-:1002600080E58EBD0DB407FEFDCF83E78EBD0DB4D6
-:1002700007FEFDCF2D9A08952D9890EA9EBD0DB4EE
-:1002800007FEFDCF262FFB019E2F921B981730F4FF
-:1002900091919EBD0DB407FEFDCFF6CF2D9A089526
-:1002A0004F925F926F927F928F929F92AF92BF9286
-:1002B000CF92DF92EF92FF920F931F93CF93DF9332
-:1002C000CDB7DEB7EB970FB6F894DEBF0FBECDBF4C
-:1002D0008091000190910101A0910201B091030170
-:1002E00088AF99AFAAAFBBAF1A821982FE013396CD
-:1002F00080E3DF011D928A95E9F7BE01685C7F4FBC
-:1003000084E00E943C012C9AB8E2BA95F1F72C984F
-:10031000412C512C32018CE2882E81E0982E02E192
-:1003200011E0CE0101967C0197E3C92E91E0D92E10
-:100330002EE3A22E21E0B22EAFECB7E01197F1F739
-:1003400000C00000BE016D5C7F4F87E00E9483000B
-:10035000823088F09F928F921F930F93FF92EF92BB
-:100360000E941F03C7010E94AB020F900F900F90D5
-:100370000F900F900F908BA985FF13C0DF92CF9243
-:100380001F930F93FF92EF920E941F03C7010E94D9
-:10039000AB020F900F900F900F900F900F9081E095
-:1003A00001C080E09BA994FF12C0BF92AF921F933F
-:1003B0000F93FF92EF920E941F03C7010E94AB02AE
-:1003C0000F900F900F900F900F900F9081E0BFEF64
-:1003D0004B1A5B0A6B0A7B0A811108C08FEF481623
-:1003E00051046104710409F0A7CF06C09FEF4916BC
-:1003F000510461047104C1F486E491E09F938F93EA
-:1004000082E191E09F938F938E010F5F1F4F1F93A7
-:100410000F930E941F03C8010E94AB020F900F9020
-:100420000F900F900F900F90BE016D5C7F4F87E093
-:100430000E9483006BA96F7087E00E940E01EB960B
-:100440000FB6F894DEBF0FBECDBFDF91CF911F91E5
-:100450000F91FF90EF90DF90CF90BF90AF909F9063
-:100460008F907F906F905F904F900895CF93DF9320
-:1004700000D000D0CDB7DEB769837A838B839C83AD
-:100480002D9880E38EBD0DB407FEFDCFFE013196A1
-:10049000CE01059621912EBD0DB407FEFDCFE817C4
-:1004A000F907C1F71EBC0DB407FEFDCF2D9A0F90C2
-:1004B0000F900F900F90DF91CF910895CF93DF931E
-:1004C00000D000D0CDB7DEB769837A838B839C835D
-:1004D0002D988AE28EBD0DB407FEFDCFFE01319648
-:1004E000CE01059621912EBD0DB407FEFDCFE81774
-:1004F000F907C1F71EBC0DB407FEFDCF2D9A0F9072
-:100500000F900F900F90DF91CF91089562E385E0F7
-:100510000E940E010E942F0164E08DE10E940E01F5
-:100520006FE38CE10E940E0166E574E382E190E0E6
-:100530000E94360266E574E382E190E00C945E026C
-:100540009093CD008093CC0088E18093C9008EE029
-:100550008093CA00089540E0242F30E0FC01019010
-:100560000020E9F73197E81BF90B2E173F0760F4DD
-:100570005091C80055FFFCCFFC01E20FF31F208112
-:100580002093CE004F5FE8CF0895CF93DF93CDB790
-:10059000DEB7E2970FB6F894DEBF0FBECDBF1A826A
-:1005A0001982FE01339680E3DF011D928A95E9F7F7
-:1005B00083E390E00E94A00284E091E09F938F93F8
-:1005C00082E191E09F938F938E010F5F1F4F1F93E6
-:1005D0000F930E941F03C8010E94AB020E94750086
-:1005E0000E941A010E9486020F900F900F900F90A8
-:1005F0000F900F9087E1C82E81E0D82E92E1E92E6E
-:1006000091E0F92E0E945001DF92CF92FF92EF927B
-:100610001F930F930E941F03C8010E94AB02BFEFFC
-:1006200029E688E1B15020408040E1F700C0000099
-:100630000F900F900F900F900F900F90E3CFAEE0C0
-:10064000B0E0E5E2F3E00C94E0050D891E8986E058
-:100650008C831A8309838FEF9FE79E838D83AE017E
-:10066000475E5F4F6F89788DCE0101960E944103EE
-:10067000EF81F885E00FF11F10822E96E4E00C94D4
-:10068000FC05ABE0B0E0E7E4F3E00C94D2056C01CC
-:100690007B018A01FC0117821682838181FFCCC114
-:1006A000CE0101963C01F6019381F70193FD8591FE
-:1006B00093FF81917F01882309F4BAC1853239F40F
-:1006C00093FD859193FF81917F01853229F4B601D5
-:1006D00090E00E943805E7CF912C212C312CFFE1CE
-:1006E000F315D8F08B3279F038F4803279F0833218
-:1006F000A1F4232D20611DC08D3261F0803369F497
-:10070000232D216016C0832D8260382EE32DE460F6
-:100710003E2E2AC0F32DF8601DC037FC2DC020ED01
-:10072000280F2A3040F08E32B9F436FC81C1232DD7
-:100730002064322E19C036FE06C08AE0989E200D35
-:100740001124922E11C0EAE02E9E200D1124222E9B
-:10075000F32DF0623F2E08C08C3621F4832D806883
-:10076000382E02C0883641F4F70193FD859193FF3E
-:1007700081917F018111B3CF982F9F7D9554933044
-:1007800028F40C5F1F4F9FE399830DC0833631F02F
-:10079000833771F0833509F059C021C0F801808199
-:1007A00089830E5F1F4F88248394912C530113C0BB
-:1007B0002801F2E04F0E511CF801A080B18036FEF6
-:1007C00003C0692D70E002C06FEF7FEFC5010E948A
-:1007D0002D054C018201F32DFF773F2E16C0280115
-:1007E00022E0420E511CF801A080B18036FE03C009
-:1007F000692D70E002C06FEF7FEFC5010E942205F6
-:100800004C01F32DF0683F2E820133FC1BC0822D7A
-:1008100090E088169906B0F4B60180E290E00E945C
-:1008200038052A94F4CFF50137FC859137FE819184
-:100830005F01B60190E00E94380521102A9421E062
-:10084000821A91088114910471F7E8C0843611F07E
-:10085000893641F5F80137FE07C0608171818281D8
-:1008600093810C5F1F4F08C060817181072E000CBF
-:10087000880B990B0E5F1F4FF32DFF763F2E97FFCE
-:1008800009C090958095709561957F4F8F4F9F4FD0
-:10089000F0683F2E2AE030E0A3010E947405882E04
-:1008A000861845C0853731F4232D2F7EB22E2AE0DD
-:1008B00030E025C0932D997FB92E8F36C1F018F402
-:1008C000883579F0B5C0803719F0883721F0B0C08D
-:1008D000E92FE061BE2EB4FE0DC0FB2DF460BF2EEB
-:1008E00009C034FE0AC0292F2660B22E06C028E0B7
-:1008F00030E005C020E130E002C020E132E0F80144
-:10090000B7FE07C060817181828193810C5F1F4FA8
-:1009100006C06081718180E090E00E5F1F4FA301EF
-:100920000E947405882E8618FB2DFF773F2E36FE19
-:100930000DC0232D2E7FA22E891458F434FE0BC037
-:1009400032FC09C0832D8E7EA82E05C0B82CA32CA6
-:1009500003C0B82C01C0B92CA4FE0FC0FE01E80DE5
-:10096000F11D8081803321F49A2D997EA92E09C032
-:10097000A2FE06C0B394B39404C08A2D867809F011
-:10098000B394A3FC11C0A0FE06C0B21488F4280CD6
-:10099000922C9B180EC0B21460F4B60180E290E075
-:1009A0000E943805B394F7CFB21418F42B1802C084
-:1009B000982C212CA4FE10C0B60180E390E00E9488
-:1009C0003805A2FE17C0A1FC03C088E790E002C072
-:1009D00088E590E0B6010CC08A2D867859F0A1FE1A
-:1009E00002C08BE201C080E2A7FC8DE2B60190E07C
-:1009F0000E943805891438F4B60180E390E00E9423
-:100A000038059A94F7CF8A94F301E80DF11D80819F
-:100A1000B60190E00E9438058110F5CF222009F43C
-:100A200042CEB60180E290E00E9438052A94F6CFCB
-:100A3000F6018681978102C08FEF9FEF2B96E2E14E
-:100A40000C94EE05FC010590615070400110D8F740
-:100A5000809590958E0F9F1F0895FC016150704006
-:100A600001900110D8F7809590958E0F9F1F0895E3
-:100A70000F931F93CF93DF93FB01238121FD03C0CD
-:100A80008FEF9FEF2CC022FF16C046815781248133
-:100A900035814217530744F4A081B1819D012F5F36
-:100AA0003F4F318320838C93268137812F5F3F4FC7
-:100AB0003783268314C08B01EC01FB010084F18590
-:100AC000E02D0995892BE1F6D80116968D919C9120
-:100AD0001797019617969C938E931697CE01DF91E8
-:100AE000CF911F910F910895FA01AA27283051F153
-:100AF000203181F1E8946F936E7F6E5F7F4F8F4F4F
-:100B00009F4FAF4FB1E03ED0B4E03CD0670F781FAD
-:100B1000891F9A1FA11D680F791F8A1F911DA11D92
-:100B20006A0F711D811D911DA11D20D009F46894CB
-:100B30003F912AE0269F11243019305D3193DEF673
-:100B4000CF010895462F4770405D4193B3E00FD029
-:100B5000C9F7F6CF462F4F70405D4A3318F0495D14
-:100B600031FD4052419302D0A9F7EACFB4E0A695F7
-:100B70009795879577956795BA95C9F70097610519
-:100B8000710508959B01AC010A2E0694579547956F
-:100B900037952795BA95C9F7620F731F841F951F64
-:100BA000A01D08952F923F924F925F926F927F9275
-:100BB0008F929F92AF92BF92CF92DF92EF92FF926D
-:100BC0000F931F93CF93DF93CDB7DEB7CA1BDB0B19
-:100BD0000FB6F894DEBF0FBECDBF09942A883988BE
-:100BE00048885F846E847D848C849B84AA84B984C5
-:100BF000C884DF80EE80FD800C811B81AA81B981D1
-:100C0000CE0FD11D0FB6F894DEBF0FBECDBFED01E4
-:060C10000895F894FFCFE7
-:100C1600DEADBEEF50726F6772616D2073746172E4
-:100C2600740025730D0A0074657374206D65737303
-:100C360061676500257330782578200072656164E8
-:100C4600206572726F720054582066696E006D617D
-:0E0C560078207265740074696D656F757400A6
-:00000001FF

weather-sensor/firmware/makefile

@@ -0,0 +1,14 @@
+all: main.hex
+
+clean:
+	rm -f main.hex
+	rm -f main
+
+flash: main.hex
+	sudo avrdude -c buspirate -b 115200 -P /dev/ttyUSB0 -p m88p -v -U flash:w:main.hex
+
+main: main.c spi.c spi.h nrf24l01.c nrf24l01.h nrf24l01_definitions.h bme280_interface.c bme280_interface.h BME280_driver/bme280.c BME280_driver/bme280.h
+	avr-gcc main.c spi.c nrf24l01.c bme280_interface.c BME280_driver/bme280.c -I BME280_driver -o main -mmcu=atmega88p -Os -Wall -Wextra -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -DF_CPU=1000000UL -D BME280_32BIT_ENABLE
+
+main.hex: main
+	avr-objcopy -O ihex -R .eeprom main main.hex

weather-sensor/firmware/nrf24l01.c

@@ -0,0 +1,342 @@
+#include <stdint.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include <stdio.h>
+#include <stdbool.h>
+
+#include "spi.h"
+#include "nrf24l01.h"
+#include "nrf24l01_definitions.h"
+
+/* TODO
+ * - Build a state machine that tracks the mode the NRF is set to
+ * - Configuration of NRF24L01 and startup
+ * - Send and Receive functions
+ * - Interrupt handling for Send and Receive
+ */
+
+void Print_Register_Contents(uint8_t address);
+void Send_TX_Flush_Command(void);
+
+/* Startup and initial configuration of the NRF24L01 */
+void Initialize_NRF24L01(void)
+{
+	CONFIG_REGISTER configRegisterContents = {.byte = 0x0};
+
+	/* Configure the AVR pins for the nrf24l01 */
+	Set_NRF24L01_Pins();
+
+	/* Wait more than 10.3 ms to make sure the nrf24l01 is running */
+	_delay_ms(11);
+
+	/* Write the PWR_UP bit of the CONFIG register (EN_CRC is also set) */
+	configRegisterContents.bits.EN_CRC = 0x1;
+	configRegisterContents.bits.PWR_UP = 0x1;
+	Write_NRF_Register(CONFIG_ADDRESS, configRegisterContents.byte);
+
+	/* Wait more than 1.5 ms for the change to take effect */
+	_delay_ms(2);
+
+	/* The NRF24L01 is now in the mode Standby-I */
+}
+
+void Set_NRF24L01_Pins(void)
+{
+	/* Set up the NRF24L01 */
+	NRF_CE_DDR |= (1 << NRF_CE_PIN);
+	NRF_CSN_DDR |= (1 << NRF_CSN_PIN);
+
+	/* Set the chip select pin to not selected */
+	NRF_CSN_PORT |= (1 << NRF_CSN_PIN);
+
+	/* Ensure that the CE pin is set to 0*/
+	NRF_CE_PORT &= ~(1 << NRF_CE_PIN);
+}
+
+void Configure_Transmission(void)
+{
+	FEATURE_REGISTER featureRegisterContents = {.byte = 0x0};
+	DYNPD_REGISTER dyndpRegisterContents = {.byte = 0x0};
+	SETUP_RETR_REGISTER setupRetrRegisterContents = {.byte = 0x0};
+	/* 
+	 * - Length of CRC (CRCO in CONFIG)
+	 * - Enable auto acknowledgment (EN_AA)
+	 *   -> Register already set correctly after reset
+	 * - Enable data pipes (EN_RXADDR)?
+	 *   -> Two pipes are already enabled on reset
+	 * - Set up address width (SETUP_AW)
+	 *   -> 3 bytes
+	 * - Automatic Retransmission (SETUP_RETR)
+	 *   -> ARD = 0b0000
+	 *   -> 3 retransmits -> ARC = 0b0011
+	 *   -> Register already set correctly after reset
+	 * - RF Channel (RF_CH)
+	 *   -> RF_CH = 0b1010000
+	 * - RF Setup (RF_SETUP)
+	 *   -> first use reset values, can be fine tuned later
+	 * - Enable dynamic payload length (DYNPD) -> command activate + 0x73, then set bits in FEATURE?
+	 */
+
+	/* Set the address width to 3 bytes */
+	//Write_NRF_Register(0x03, 0x1);
+
+	/* Set the frequency to 1450 MHz */
+	Write_NRF_Register(RF_CH_ADDRESS, 0x32);
+
+	/* Enable dynamic payload length */
+	Send_Activate_Command();
+	featureRegisterContents.bits.EN_DPL = 1; // enable dynamic payload length
+	Write_NRF_Register(FEATURE_ADDRESS, featureRegisterContents.byte);
+
+	/* */
+	setupRetrRegisterContents.bits.ARC = 0x3;
+	setupRetrRegisterContents.bits.ARD = 0xF;
+	Write_NRF_Register(SETUP_RETR_ADDRESS, setupRetrRegisterContents.byte);
+
+	/* set dynamic payload length for all data pipes */
+	dyndpRegisterContents.bits.DPL_P0 = 1;
+	dyndpRegisterContents.bits.DPL_P1 = 1;
+	dyndpRegisterContents.bits.DPL_P2 = 1;
+	dyndpRegisterContents.bits.DPL_P3 = 1;
+	dyndpRegisterContents.bits.DPL_P4 = 1;
+	dyndpRegisterContents.bits.DPL_P5 = 1;
+	Write_NRF_Register(DYNPD_ADDRESS, dyndpRegisterContents.byte);
+
+	/* Set the TX address */
+	Set_TX_Address(0x123456);
+
+	Set_RX_P0_Address(0x123456);
+	
+
+	// TODO: set addresses for all data pipes
+}
+
+void NRF24L01_Send_Message(uint8_t *buffer, uint8_t length)
+{
+	bool transmissionFinished = false;
+
+	STATUS_REGISTER statusRegisterContents = {.byte = 0x0};
+	uint32_t timeout = 0;
+	/* TODO:
+	 * - if needed: PRIM_RX = 0
+	 * - Set CE = 1 for more than 10 us
+	 * - Wait until the transmission is finished
+	 * - Read number of retries for debug purposes
+	 * - Check if the FIFO is empty -> if not, flush it
+	 * - reset the interupts of the STATUS
+	 */
+	
+	/* TODO: messages with more than 32 byte length */
+	if ((length > 32) || (length == 0))
+	{
+		return;
+	}
+
+	Write_Message_To_TX_FIFO(length, buffer);
+
+	/* Set CE = 1 for more than 10 us */
+	NRF_CE_PORT |= (1 << NRF_CE_PIN);
+	_delay_us(15);
+	NRF_CE_PORT &= ~(1 << NRF_CE_PIN);
+
+
+	do
+	{
+		_delay_ms(1);
+		/* TODO: instead of polling the status register use the IRQ to spawn an interrupt as the
+		 * constant polling may induce transmission errors:
+		 * https://forum.mysensors.org/topic/10452/nrf24l01-communication-failure-root-cause-and-solution
+		 */
+		statusRegisterContents.byte = Read_NRF_Status_Register();
+
+		if (statusRegisterContents.bits.TX_DS == 1)
+		{
+			transmissionFinished = true;
+		}
+
+		if (statusRegisterContents.bits.MAX_RT == 1)
+		{
+			transmissionFinished = true; //TODO: indicate failure
+
+			Send_TX_Flush_Command(); /* Remove the packet from the TX FIFO as it is not done automatically */
+		}
+		
+		timeout ++; // TODO: this should work without the time out, as MAX_RT should be triggered if no ACK is received
+	} while ((transmissionFinished == false) && (timeout < 0xFF));
+
+	/* Reset the interrupts */
+	statusRegisterContents.byte = Read_NRF_Status_Register();
+	statusRegisterContents.bits.TX_DS = 1;
+	statusRegisterContents.bits.MAX_RT = 1;
+	Write_NRF_Register(STATUS_ADDRESS, statusRegisterContents.byte);
+}
+
+void Print_Register_Contents(uint8_t address)
+{
+	uint8_t registerContent[5];
+	uint8_t lengthRead;
+	char registerContentString[30];
+
+
+	lengthRead = Read_NRF_Register(address, registerContent);
+
+	registerContentString[0] = '\0';
+	for (uint8_t i = 0; i < lengthRead; i++)
+	{
+		sprintf(registerContentString, "%s0x%x ", registerContentString, registerContent[i]);
+	}
+}
+
+
+
+
+/* Send a message:
+ * - Set PRIM_RX = 0 and add one message to the TX-FIFO
+ * - Set CE=1 for more than 10 us
+ * - The NRF takes 130 us to enter the TX Mode
+ * - An Interrupt is generated once the 
+ * - 
+ */
+
+
+/* Set the NRF to RX Mode */
+
+/* Disable the RX Mode */
+
+
+
+
+uint8_t Read_NRF_Status_Register(void)
+{
+	uint8_t registerContents;
+
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+	registerContents = SPI_Transfer_Byte(0x00);
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+	return registerContents;
+}
+
+uint8_t Read_NRF_Register(uint8_t address, uint8_t * registerContents)
+{
+	/* TODO: simplify this function, as the registers with more than one byte are accessed with other functions */
+	uint8_t numberOfBytes = 0;
+
+	if ((address == 0x0A) ||
+	    (address == 0x0B) ||
+	    (address == 0x10))
+	{
+		numberOfBytes = 5;
+	}
+	else
+	{
+		numberOfBytes = 1;
+	}
+
+	/* First write the address */
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+
+	SPI_Transfer_Byte(address);
+
+	/* Read the register bytes */
+	for (uint8_t i = 0; i < numberOfBytes; i++)
+	{
+		/* Write dummy data to shift in the register content */
+		registerContents[i] = SPI_Transfer_Byte(0x0);
+	}
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+	return numberOfBytes;
+}
+
+void Write_NRF_Register(uint8_t address, uint8_t registerContents)
+{
+	/* First write the write command with the address */
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+	SPI_Transfer_Byte(address | 0x20);
+
+	/* Write the data byte */
+	SPI_Transfer_Byte(registerContents);
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+}
+
+// TODO: clean up functions
+void Send_Activate_Command(void)
+{
+	/* First write the write command with the address */
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+	SPI_Transfer_Byte(0x50);
+
+	/* Write the data byte */
+	SPI_Transfer_Byte(0x73);
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+}
+
+void Send_TX_Flush_Command(void)
+{
+	/* First write the write command with the address */
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+	SPI_Transfer_Byte(0xE1);
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+}
+
+
+
+void Write_Message_To_TX_FIFO(uint8_t length, uint8_t * buffer)
+{
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+	/* Issue the write command: */
+	SPI_Transfer_Byte(0xA0);
+
+	/* Write the data bytes */
+	for (uint8_t i = 0; i < length; i++)
+	{
+		SPI_Transfer_Byte(buffer[i]);
+	}
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+}
+
+void Set_TX_Address(uint32_t txAddress)
+{
+	uint8_t * buffer = (uint8_t*) &txAddress;
+
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+	SPI_Transfer_Byte(TX_ADDR_ADDRESS | 0x20);
+	/* Write the data byte */
+	for (uint8_t i = 0; i < 4; i ++)
+	{
+		SPI_Transfer_Byte(buffer[i]);
+	}
+	SPI_Transfer_Byte(0x0);
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+}
+
+void Set_RX_P0_Address(uint32_t rxAddress)
+{
+	uint8_t * buffer = (uint8_t*) &rxAddress;
+
+	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+
+	SPI_Transfer_Byte(RX_ADDR_P0_ADDRESS | 0x20);
+
+	/* Write the data byte */
+	for (uint8_t i = 0; i < 4; i ++)
+	{
+		SPI_Transfer_Byte(buffer[i]);
+	}
+	SPI_Transfer_Byte(0x0);
+
+	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+}
+
+//TODO: only write the used bytes into the address registers & add generic write functions

weather-sensor/firmware/nrf24l01.h

@@ -0,0 +1,32 @@
+#ifndef NRF24L01_H
+#define NRF24L01_H
+
+
+
+/* AVR I/O pin definionts */
+#define NRF_CE_DDR   DDRD
+#define NRF_CE_PORT  PORTD
+#define NRF_CE_PIN   PD7
+
+#define NRF_CSN_DDR   DDRD
+#define NRF_CSN_PORT  PORTD
+#define NRF_CSN_PIN   PD6
+
+#define NRF_IRQ_DDR   DDRD
+#define NRF_IRQ_PORT  PORTD
+#define NRF_IRQ_PIN   PD5
+
+void Initialize_NRF24L01(void);
+void Set_NRF24L01_Pins(void);
+void Configure_Transmission(void);
+uint8_t Read_NRF_Status_Register(void);
+uint8_t Read_NRF_Register(uint8_t address, uint8_t * registerContents);
+void Write_NRF_Register(uint8_t address, uint8_t registerContents);
+void Send_Activate_Command(void);
+
+void NRF24L01_Send_Message(uint8_t *buffer, uint8_t length);
+void Write_Message_To_TX_FIFO(uint8_t length, uint8_t * buffer);
+void Set_TX_Address(uint32_t txAddress);
+void Set_RX_P0_Address(uint32_t rxAddress);
+
+#endif

weather-sensor/firmware/nrf24l01_definitions.h

@@ -3,32 +3,32 @@
 
 
 /* NRF24L01 register mnemonic definitions */
-#define CONFIG 0x0
-#define EN_AA 0x1
-#define EN_RXADDR 0x2
-#define SETUP_AW 0x3
-#define SETUP_RETR 0x4
-#define RF_CH 0x5
-#define RF_SETUP 0x6
-#define STATUS 0x7
-#define OBSERVE_TX 0x8
-#define CD 0x9
-#define RX_ADDR_P0 0xA
-#define RX_ADDR_P1 0xB
-#define RX_ADDR_P2 0xC
-#define RX_ADDR_P3 0xD
-#define RX_ADDR_P4 0xE
-#define RX_ADDR_P5 0xF
-#define TX_ADDR 0x10
-#define RX_PW_P0 0x11
-#define RX_PW_P1 0x12
-#define RX_PW_P2 0x13
-#define RX_PW_P3 0x14
-#define RX_PW_P4 0x15
-#define RX_PW_P5 0x16
-#define FIFO_STATUS 0x17
-#define DYNPD 0x1C
-#define FEATURE 0x1D
+#define CONFIG_ADDRESS 0x0
+#define EN_AA_ADDRESS 0x1
+#define EN_RXADDR_ADDRESS 0x2
+#define SETUP_AW_ADDRESS 0x3
+#define SETUP_RETR_ADDRESS 0x4
+#define RF_CH_ADDRESS 0x5
+#define RF_SETUP_ADDRESS 0x6
+#define STATUS_ADDRESS 0x7
+#define OBSERVE_TX_ADDRESS 0x8
+#define CD_ADDRESS 0x9
+#define RX_ADDR_P0_ADDRESS 0xA
+#define RX_ADDR_P1_ADDRESS 0xB
+#define RX_ADDR_P2_ADDRESS 0xC
+#define RX_ADDR_P3_ADDRESS 0xD
+#define RX_ADDR_P4_ADDRESS 0xE
+#define RX_ADDR_P5_ADDRESS 0xF
+#define TX_ADDR_ADDRESS 0x10
+#define RX_PW_P0_ADDRESS 0x11
+#define RX_PW_P1_ADDRESS 0x12
+#define RX_PW_P2_ADDRESS 0x13
+#define RX_PW_P3_ADDRESS 0x14
+#define RX_PW_P4_ADDRESS 0x15
+#define RX_PW_P5_ADDRESS 0x16
+#define FIFO_STATUS_ADDRESS 0x17
+#define DYNPD_ADDRESS 0x1C
+#define FEATURE_ADDRESS 0x1D
 
 /* Register bits definitions */
 /* CONFIG*/
@@ -37,46 +37,205 @@ typedef union
 	uint8_t byte;
 	struct
 	{
-		 uint8_t bit012 : 3;
-		 uint8_t bit34 : 2;
-		 uint8_t bit5 : 1;
-		 uint8_t bit6 : 1;
-		 uint8_t bit7 : 1;
+		uint8_t PRIM_RX     : 1;
+		uint8_t PWR_UP      : 1;
+		uint8_t CRCO        : 1;
+		uint8_t EN_CRC      : 1;
+		uint8_t MASK_MAX_RT : 1;
+		uint8_t MASK_TX_DS  : 1;
+		uint8_t MASK_RX_DR  : 1;
+		uint8_t RESERVED    : 1;
 	}bits;
 }CONFIG_REGISTER;
 
-#define MASK_RX_DR (1<<6)
-#define MASK_TX_DS (1<<5)
-#define MASK_MAX_RT (1<<4)
-#define EN_CRC (1<<3)
-#define CRCO (1<<2)
-#define PWR_UP (1<<1)
-#define PRIM_RX (1<<0)
-
 /*EN_AA */
-#define ENAA_P5 (1<<5)
-#define ENAA_P4 (1<<4)
-#define ENAA_P3 (1<<3)
-#define ENAA_P2 (1<<2)
-#define ENAA_P1 (1<<1)
-#define ENAA_P0 (1<<0)
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		uint8_t ENAA_P0  : 1;
+		uint8_t ENAA_P1  : 1;
+		uint8_t ENAA_P2  : 1;
+		uint8_t ENAA_P3  : 1;
+		uint8_t ENAA_P4  : 1;
+		uint8_t ENAA_P5  : 1;
+		uint8_t RESERVED : 2;
+	}bits;
+}EN_AA_REGISTER;
 
 /* EN_RXADDR */
-#define ERX_P5 (1<<5)
-#define ERX_P4 (1<<4)
-#define ERX_P3 (1<<3)
-#define ERX_P2 (1<<2)
-#define ERX_P1 (1<<1)
-#define ERX_P0 (1<<0)
-
-
-#define  (1<<)
-#define  (1<<)
-#define  (1<<)
-#define  (1<<)
-#define  (1<<)
-#define  (1<<)
-#define  (1<<)
-#define  (1<<)
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		uint8_t ERX_P0   : 1;
+		uint8_t ERX_P1   : 1;
+		uint8_t ERX_P2   : 1;
+		uint8_t ERX_P3   : 1;
+		uint8_t ERX_P4   : 1;
+		uint8_t ERX_P5   : 1;
+		uint8_t RESERVED : 2;
+	}bits;
+}EN_RXADDR_REGISTER;
+
+/* SETUP_AW */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t AW : 2;
+		 uint8_t RESERVED : 6;
+	}bits;
+}SETUP_AW_REGISTER;
+
+#define ADDRESS_WIDTH_3_BYTES 0x1
+#define ADDRESS_WIDTH_4_BYTES 0x2
+#define ADDRESS_WIDTH_5_BYTES 0x3
+
+/* SETUP_RETR */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t ARC : 4;
+		 uint8_t ARD : 4;
+	}bits;
+}SETUP_RETR_REGISTER;
+
+/* RF_CH */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t RF_CH : 7;
+		 uint8_t RESERVED : 1;
+	}bits;
+}RF_CH_REGISTER;
+
+/* RF_SETUP */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t LNA_HCURR : 1;
+		 uint8_t RF_PWR    : 2;
+		 uint8_t RF_DR     : 1;
+		 uint8_t PLL_LOCK  : 1;
+		 uint8_t RESERVED  : 3;
+	}bits;
+}RF_SETUP_REGISTER;
+
+#define RF_DATA_RATE_1MBPS 0x0
+#define RF_DATA_RATE_2MBPS 0x1
+
+#define RF_OUTPUT_POWER_MINUS_18DBM
+#define RF_OUTPUT_POWER_MINUS_12DBM
+#define RF_OUTPUT_POWER_MINUS_16DBM
+#define RF_OUTPUT_POWER_0DBM
+
+// TODO: change order of all bit fields!!!
+
+/* STATUS */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t TX_FULL  : 1;
+		 uint8_t RX_P_NO  : 3;
+		 uint8_t MAX_RT   : 1;
+		 uint8_t TX_DS    : 1;
+		 uint8_t RX_DR    : 1;
+		 uint8_t RESERVED : 1;
+	}bits;
+}STATUS_REGISTER;
+
+#define RX_FIFO_EMPTY 0x7
+
+/* OBSERVE_TX */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t ARC_CNT  : 4;
+		 uint8_t PLOS_CNT : 4;
+	}bits;
+}OBSERVE_TX_REGISTER;
+
+/* CD */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t CD : 1;
+		 uint8_t RESERVED : 7;
+	}bits;
+}CD_REGISTER;
+
+/* RX_PW_Pn */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t RESERVED : 2;
+		 uint8_t RX_PW_Pn : 6;
+	}bits;
+}RX_PW_Pn_REGISTER;
+
+/* FIFO_STATUS */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t RX_EMPTY : 1;
+		 uint8_t RX_FULL  : 1;
+		 uint8_t RESERVED1 : 2;
+		 uint8_t TX_EMPTY : 1;
+		 uint8_t TX_FULL  : 1;
+		 uint8_t TX_REUSE : 1;
+		 uint8_t RESERVED0 : 1;
+	}bits;
+}FIFO_STATUS_REGISTER;
+
+/* DYNPD */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t DPL_P0   : 1;
+		 uint8_t DPL_P1   : 1;
+		 uint8_t DPL_P2   : 1;
+		 uint8_t DPL_P3   : 1;
+		 uint8_t DPL_P4   : 1;
+		 uint8_t DPL_P5   : 1;
+		 uint8_t RESERVED : 2;
+	}bits;
+}DYNPD_REGISTER;
+
+/* FEATURE */
+typedef union
+{
+	uint8_t byte;
+	struct
+	{
+		 uint8_t EN_DYN_ACK : 1;
+		 uint8_t EN_ACK_PAY : 1;
+		 uint8_t EN_DPL     : 1;
+		 uint8_t RESERVED   : 5;
+	}bits;
+}FEATURE_REGISTER;
 
 #endif
+
+

weather-sensor/firmware/spi.c

@@ -0,0 +1,33 @@
+#include <avr/io.h>
+
+/* Pin Definitions: */
+#define SPI_DDR       DDRB
+#define SPI_SCK_PIN   PB5
+#define SPI_MOSI_PIN  PB3
+#define SPI_MISO_PIN  PB4
+
+
+void Initialize_SPI(void)
+{
+	/* Set MOSI and SCK output, all others input */
+	SPI_DDR = (1<<SPI_MOSI_PIN)|(1<<SPI_SCK_PIN);
+	/* Enable SPI, Master, set clock rate fck/16 */
+	SPCR = (1<<SPE)|(1<<MSTR);
+}
+
+void SPI_Start_Transmission(volatile uint8_t *port, uint8_t pinNumber)
+{
+	*port &= ~(1<<pinNumber);
+}
+
+uint8_t SPI_Transfer_Byte(uint8_t byteToSend)
+{
+	SPDR = byteToSend;
+	while(!(SPSR & (1<<SPIF))); // Wait for transmission complete
+	return SPDR;
+}
+
+void SPI_Stop_Transmission(volatile uint8_t *port, uint8_t pinNumber)
+{
+	*port |= (1<<pinNumber);
+}

weather-sensor/firmware/spi.h

@@ -0,0 +1,9 @@
+#ifndef SPI_H
+#define SPI_H
+
+void Initialize_SPI(void);
+void SPI_Start_Transmission(volatile uint8_t *port, uint8_t pinNumber);
+uint8_t SPI_Transfer_Byte(uint8_t byte);
+void SPI_Stop_Transmission(volatile uint8_t *port, uint8_t pinNumber);
+
+#endif