Rework the makefile and optimize the code for flash space

weather-sensor/firmware/.gitignore

 main
 *.hex
+*.o
 
 
 *.swp

weather-sensor/firmware/bme280_interface.c

 #include <avr/io.h>
 #include <util/delay.h>
+#include <string.h>
 
 #include "spi.h"
 #include "bme280.h"
 /* Get one measurement in forced mode */
 void BME280_Get_Measurement(struct bme280_data * data)
 {
+	memset(data, 0, sizeof(struct bme280_data));
 	bme280_set_sensor_mode(BME280_FORCED_MODE, &deviceStructure);
 	deviceStructure.delay_ms(req_delay);
 	bme280_get_sensor_data(BME280_ALL, data, &deviceStructure);

weather-sensor/firmware/makefile

+CFLAGS = -DF_CPU=1000000UL -D BME280_32BIT_ENABLE -I BME280_driver -mmcu=atmega88p -Os -flto -Wall -Wextra -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
+DEPS = spi.h nrf24l01.h nrf24l01_definitions.h bme280_interface.h BME280_driver/bme280.h led.h pin_programming.h crc.h encryption.h
+
 all: main.hex
 
 clean:
 	rm -f main.hex
 	rm -f main
+	rm -f obj/*.o
 
 flash: main.hex
 	sudo avrdude -c buspirate -b 115200 -P /dev/ttyUSB1 -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 led.h pin_programming.c pin_programming.h crc.c crc.h
-	avr-gcc main.c spi.c nrf24l01.c bme280_interface.c BME280_driver/bme280.c pin_programming.c crc.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
+obj/%.o: %.c $(DEPS)
+	avr-gcc -c $< -o $@ $(CFLAGS)
+
+obj/%.o: BME280_driver/%.c $(DEPS)
+	avr-gcc -c $< -o $@ $(CFLAGS)
+
+main: obj/main.o obj/spi.o obj/nrf24l01.o obj/bme280_interface.o obj/bme280.o obj/pin_programming.o obj/crc.o obj/encryption.o
+	avr-gcc $^ -o $@ $(CFLAGS)
 
 main.hex: main
 	avr-objcopy -O ihex -R .eeprom main main.hex

weather-sensor/firmware/nrf24l01.c

 void Print_Register_Contents(uint8_t address);
 void Send_TX_Flush_Command(void);
 
+static void Write_Two_Bytes(uint8_t byte1, uint8_t byte2);
+static void Write_Byte_And_Buffer(uint8_t byte, uint8_t * buffer, uint8_t length);
+
 /* Startup and initial configuration of the NRF24L01 */
 void Initialize_NRF24L01(void)
 {
 	return;
 }
 
-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;
 	return registerContents;
 }
 
+
+/* TODO: rewrite the read register function if it is needed (remove the read operations for the 5-byte registers)*/
+#if 0
 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 */
 	return numberOfBytes;
 }
 
+#endif
+
 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);
+	Write_Two_Bytes(address | 0x20, registerContents);
 }
 
-// TODO: clean up functions
 void Send_Activate_Command(void)
 {
-	/* First write the write command with the address */
+	Write_Two_Bytes(0x50, 0x73);
+}
+
+static void Write_Two_Bytes(uint8_t byte1, uint8_t byte2)
+{
 	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
-	SPI_Transfer_Byte(0x50);
 
-	/* Write the data byte */
-	SPI_Transfer_Byte(0x73);
+	SPI_Transfer_Byte(byte1);
+	SPI_Transfer_Byte(byte2);
 
 	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);
+	Write_Byte_And_Buffer(0xA0, buffer, length);
 }
 
 void Set_TX_Address(uint8_t * txAddress, uint8_t length)
 {
-	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 < length; i ++)
-	{
-		SPI_Transfer_Byte(txAddress[i]);
-	}
-
-	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
+	Write_Byte_And_Buffer(TX_ADDR_ADDRESS | 0x20, txAddress, length);
 }
 
 void Set_RX_P0_Address(uint8_t * rxAddress, uint8_t length)
+{
+	Write_Byte_And_Buffer(RX_ADDR_P0_ADDRESS | 0x20, rxAddress, length);
+}
+
+static void Write_Byte_And_Buffer(uint8_t byte, uint8_t * buffer, uint8_t length)
 {
 	SPI_Start_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);
 
-	SPI_Transfer_Byte(RX_ADDR_P0_ADDRESS | 0x20);
+	SPI_Transfer_Byte(byte);
 
 	/* Write the data byte */
 	for (uint8_t i = 0; i < length; i ++)
 	{
-		SPI_Transfer_Byte(rxAddress[i]);
+		SPI_Transfer_Byte(buffer[i]);
 	}
 
 	SPI_Stop_Transmission(&NRF_CSN_PORT, NRF_CSN_PIN);

weather-sensor/firmware/nrf24l01.h

 		} values;
 		uint8_t buffer[PACKET_BUFFER_LENGTH];
 	}payload;
-	//uint8_t buffer[PACKET_BUFFER_LENGTH];
 	uint16_t crc;
 } PACKET;