Assigning Valuse To Constants

[Steven 0]

Header file

#define nrf24l01_CE_IOREGISTER PORTB

#define nrf24l01_CE_PINMASK 0x01

 

C file

nrf24l01_CE_IOREGISTER &= ~nrf24l01_CE_PINMASK;

 

I’m receiving the following compiler error:

c(510): error: left operand must be l-value c(510:9): error: failed to generate expression

 

I understand that this is because im trying to assign a value to a constant. Is there anyway around this???

[Steven 0]

I think i may have discovered my own solution by using the set_bit and clear_bit functions. Does the boost C compiler have a spi.h header file for using the hardware spi on the 16f pics?

[Pavel 0]

In C you can not assign a value to a constant (don't confuse this with const variable thought). The expression you quoted will look like this after passing the pre-processor:

 

6 &= ~1

 

This is an assignment expression and in C left side of an assignment expression must be an l-value.

 

Regards,

Pavel

[Steven 0]

After much reading I think i have a better grasp of the concept. Thanks for the help. Also does the sourceBoost compiler have a spi.h header for the spi on the 16F pic's?

[Pavel 0]

...Also does the sourceBoost compiler have a spi.h header for the spi on the 16F pic's?...

 

There are no SPI libraries or headers supplied in SourceBoost. We recommend to aks on the BoostC programming forum. There are a lot of talented BoostC users there.

 

Regards,

Pavel