* Allow COPTIM to be set outside Makefile

* Use -Wall -Werror
* Fix some warnings

Makefile

@@ -5,7 +5,8 @@ NAME=quad
 SSRCS=crt0.s
 CSRCS=main.c i2c.c wmp.c timer.c
 
-CFLAGS=-march=armv4t -msoft-float -O1
+COPTIM?=-O1
+CFLAGS=-march=armv4t -msoft-float $(COPTIM) -Wall -Werror
 
 LDSCRIPT=lpc2103_flash.ld
 CC=arm-elf-gcc

i2c.c

@@ -79,7 +79,7 @@ bool i2c_send_address(int addr, bool write)
 	return i2c_send_data((addr<<1) + (write?0:1));
 }
 
-bool i2c_send_data(int data)
+bool i2c_send_data(unsigned int data)
 {
 	IREG(I2DAT) = data;
 	IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG;
@@ -94,7 +94,7 @@ bool i2c_send_data(int data)
 	}
 }
 
-bool i2c_receive_data(int *data, bool last)
+bool i2c_receive_data(unsigned int *data, bool last)
 {
 	if (!last)
 		IREG(I2CONSET) = AAFLAG;

i2c.h

@@ -10,8 +10,8 @@ int i2c_conreg(void);
 int i2c_statreg(void);
 bool i2c_send_start(void);
 bool i2c_send_address(int addr, bool write);
-bool i2c_send_data(int data);
-bool i2c_receive_data(int *data, bool last);
+bool i2c_send_data(unsigned int data);
+bool i2c_receive_data(unsigned int *data, bool last);
 void i2c_send_stop(void);
 
 #endif /* __I2C_H */

main.c

@@ -228,7 +228,6 @@ void average_sample(void)
 
 int main(void) {
 	int i;
-	int data;
 	init_uart();
 	init_i2c();
 	init_pins();

wmp.c

@@ -13,6 +13,7 @@ bool wmp_init(void)
 	if (!i2c_send_data(0x04))
 		return FALSE;
 	i2c_send_stop();
+	return TRUE;
 }
 
 unsigned char wmp_calibration_data[0x20];