Operational Amplifier

Functions for configuring and using the operational amplifier on the SAM L21. More...

Macros
#define	OPAMP_MUXNEG_NEG   (0)
#define	OPAMP_MUXNEG_LADDER   (1)
#define	OPAMP_MUXNEG_OUT   (2)
#define	OPAMP0_MUXNEG_DAC   (3)
#define	OPAMP1_MUXNEG_DAC   (3)
#define	OPAMP2_MUXNEG_DAC   (5)
#define	OPAMP2_MUXNEG_NEG_0   (3)
#define	OPAMP2_MUXNEG_NEG_1   (4)
#define	OPAMP_MUXPOS_POS   (0)
#define	OPAMP_MUXPOS_LADDER   (1)
#define	OPAMP0_MUXPOS_DAC   (2)
#define	OPAMP1_MUXPOS_OUT_0   (2)
#define	OPAMP2_MUXPOS_OUT_1   (2)
#define	OPAMP_MUXPOS_GND   (3)
#define	OPAMP2_MUXPOS_POS_0   (4)
#define	OPAMP2_MUXPOS_POS_1   (5)
#define	OPAMP2_MUXPOS_LADDER_0   (6)
#define	OPAMP_POTMUX_RATIO_14_2   (0)
#define	OPAMP_POTMUX_RATIO_12_4   (1)
#define	OPAMP_POTMUX_RATIO_8_8   (2)
#define	OPAMP_POTMUX_RATIO_6_10   (3)
#define	OPAMP_POTMUX_RATIO_4_12   (4)
#define	OPAMP_POTMUX_RATIO_3_13   (5)
#define	OPAMP_POTMUX_RATIO_2_14   (6)
#define	OPAMP_POTMUX_RATIO_1_15   (7)
#define	OPAMP_RES1MUX_POS   (0)
#define	OPAMP_RES1MUX_NEG   (1)
#define	OPAMP0_RES1MUX_DAC   (2)
#define	OPAMP1_RES1MUX_OUT_0   (2)
#define	OPAMP2_RES1MUX_OUT_1   (2)
#define	OPAMP_RES1MUX_GND   (3)
#define	OPAMP_RES1MUX_NC   (4)
#define	OPAMP_RES2MUX_VCC   (0)
#define	OPAMP_RES2MUX_OUT   (1)
#define	OPAMP_RES2MUX_NC   (2)

Functions
void	opamp_init (void)
	Initializes the OPAMP peripheral, but does not enable any opamps.
void	opamp_enable (uint16_t instance)
	Enables the given opamp.
void	opamp_set_muxpos (uint16_t instance, uint8_t muxpos)
	Sets the positive input mux for the given opamp.
void	opamp_set_muxneg (uint16_t instance, uint8_t muxneg)
	Sets the negative input mux for the given opamp.
void	opamp_set_potmux (uint16_t instance, uint8_t potmux)
	Sets the potentiometer (resistor ladder) mux for the given opamp.
void	opamp_set_res1mux (uint16_t instance, uint8_t res1mux)
	Sets the connection for the bottom of the resistor ladder for the given instance.
void	opamp_set_res2mux (uint16_t instance, uint8_t res2mux)
	Sets the connection for the top of the resistor ladder for the given instance.
void	opamp_set_analog_connection (uint16_t instance, bool connected)
	Sets or removes the connection from the opamp output to the ADC / AC.
void	opamp_disable (uint16_t instance)
	Disables the given opamp.

Detailed Description

Functions for configuring and using the operational amplifier on the SAM L21.

Function Documentation

opamp_disable()

void opamp_disable

(

uint16_t

instance

)

Disables the given opamp.

Parameters

instance

The opamp instance to disable.

Note

You should disable the opamp before reconfiguring it, and re-enable it afterwards.

opamp_enable()

void opamp_enable

(

uint16_t

instance

)

Enables the given opamp.

Parameters

instance

The opamp instance to enable.

opamp_set_analog_connection()

void opamp_set_analog_connection	(	uint16_t	instance,
		bool	connected
	)

Sets or removes the connection from the opamp output to the ADC / AC.

Parameters

instance	The opamp instance to configure.
connected	True to connect the opamp output to the ADC / AC, false to disconnect it.

opamp_set_muxneg()

void opamp_set_muxneg	(	uint16_t	instance,
		uint8_t	muxneg
	)

Sets the negative input mux for the given opamp.

Parameters

instance

The opamp instance to configure.

muxneg

The desired connection, one of: OPAMP_MUXNEG_NEG - the negative input pin for this instance OPAMP_MUXNEG_LADDER - the resistor ladder tap for this instance OPAMP_MUXNEG_OUT - the output of this instance OPAMP0_MUXNEG_DAC - the DAC output (only valid for OPAMP0) OPAMP1_MUXNEG_DAC - the DAC output (only valid for OPAMP1) OPAMP2_MUXNEG_DAC - the DAC output (only valid for OPAMP2) OPAMP2_MUXNEG_NEG_0 - OPAMP0's negative input pin (only valid for OPAMP2) OPAMP2_MUXNEG_NEG_1 - OPAMP1's negative input pin (only valid for OPAMP2)

opamp_set_muxpos()

void opamp_set_muxpos	(	uint16_t	instance,
		uint8_t	muxpos
	)

Sets the positive input mux for the given opamp.

Parameters

instance

The opamp instance to configure.

muxpos

The desired connection, one of: OPAMP_MUXPOS_POS - the positive input pin for this instance OPAMP_MUXPOS_GND - ground OPAMP_MUXPOS_LADDER - the resistor ladder tap for this instance OPAMP0_MUXPOS_DAC - the DAC output (only valid for OPAMP0) OPAMP1_MUXPOS_OUT_0 - OPAMP0's output (only valid for OPAMP1) OPAMP2_MUXPOS_OUT_1 - OPAMP1's output (only valid for OPAMP2) OPAMP2_MUXPOS_POS_0 - OPAMP0's positive input pin (only valid for OPAMP2) OPAMP2_MUXPOS_POS_1 - OPAMP1's positive input pin (only valid for OPAMP2) OPAMP2_MUXPOS_LADDER_0 - OPAMP0's resistor ladder tap (only valid for OPAMP2)

opamp_set_potmux()

void opamp_set_potmux	(	uint16_t	instance,
		uint8_t	potmux
	)

Sets the potentiometer (resistor ladder) mux for the given opamp.

Parameters

instance	The opamp instance to configure.
potmux	The desired resistor ladder ratio, one of: OPAMP_POTMUX_RATIO_14_2 - 14:2 ratio OPAMP_POTMUX_RATIO_12_4 - 12:4 ratio OPAMP_POTMUX_RATIO_8_8 - 8:8 ratio OPAMP_POTMUX_RATIO_6_10 - 6:10 ratio OPAMP_POTMUX_RATIO_4_12 - 4:12 ratio OPAMP_POTMUX_RATIO_3_13 - 3:13 ratio OPAMP_POTMUX_RATIO_2_14 - 2:14 ratio OPAMP_POTMUX_RATIO_1_15 - 1:15 ratio

opamp_set_res1mux()

void opamp_set_res1mux	(	uint16_t	instance,
		uint8_t	res1mux
	)

Sets the connection for the bottom of the resistor ladder for the given instance.

Parameters

instance	The opamp instance to configure.
res1mux	The desired connection, one of: OPAMP_RES1MUX_POS - the positive input pin for this instance OPAMP_RES1MUX_NEG - the negative input pin for this instance OPAMP_RES1MUX_GND - ground OPAMP0_RES1MUX_DAC - the DAC output (only valid for OPAMP0) OPAMP1_RES1MUX_OUT_0 - OPAMP0's output (only valid for OPAMP1) OPAMP2_RES1MUX_OUT_1 - OPAMP1's output (only valid for OPAMP2) OPAMP_RES1MUX_NC - not connected

opamp_set_res2mux()

void opamp_set_res2mux	(	uint16_t	instance,
		uint8_t	res2mux
	)

Sets the connection for the top of the resistor ladder for the given instance.

Parameters

instance	The opamp instance to configure.
res2mux	The desired connection, one of: OPAMP_RES2MUX_VCC - VDDANA OPAMP_RES2MUX_OUT - the output of this instance OPAMP_RES2MUX_NC - not connected