adc.c File Reference

Core ADC library. More...

#include "adc.h"
#include "core_config.h"
#include <stdio.h>
#include <stdbool.h>
#include <stm32g4xx_hal.h>
#include <stm32g4xx_hal_adc.h>
#include <string.h>
#include "gpio.h"
#include "clock.h"
#include "error_handler.h"

Functions
bool	core_ADC_init (ADC_TypeDef *adc)
	Initialize an ADC module, including its clock. Also performs calibration. GPIO ports are not initialized.
uint16_t	core_ADC_read_vrefint ()
bool	core_ADC_setup_pin (GPIO_TypeDef *port, uint32_t pin, uint8_t opamp)
	Set up a pin as an analog input.
bool	core_ADC_read_channel (GPIO_TypeDef *port, uint32_t pin, uint16_t *result)
	Read the value of an analog input as a value between 0 and 4095.

Detailed Description

Core ADC library.

This core library component is used to initialize ADCs and read from analog inputs.

Initialization

Before initializing any pins, the user code must initialize one or more ADC modules.

To initialize a pin, the user code calls core_ADC_setup_pin(). This function takes the port and pin number as well as a third argument specifying whether the analog signal should be routed through an internal op amp follower circuit. This will improve the accuracy of the measurement when the analog input is fed from a high-impedance source

If core_ADC_setup_pin() returns 0, then the desired pin cannot be connected to any of the ADCs that are currently initialized. It may be necessary to initialize an additional ADC module or change the pin the analog input is connected to.

Reading

To read from an analog input, the user code calls core_ADC_read_channel(). The result is stored in a pointer passed as an argument, and the return value specifies whether the conversion was successful or not.

Table of connections

The table below indicates which pins connect to which ADC and whether an op amp can be connected in between the input and the ADC. If a table cell contains a number, then the pin corresponding to the row connects to the ADC corrsponding to the column directly. If the cell also indicates an op amp (OPAMP1-OPAMP6), then the pin can be connected to the ADC via an op amp. Note that not all chips will have all 5 ADCs.

Pin	ADC1	ADC2	ADC3	ADC4	ADC5
PA0	1	1
PA1	OPAMP1/2	OPAMP3/2	OPAMP3
PA2	3
PA3	OPAMP1/4
PA4		17
PA5		13
PA6		3
PA7	OPAMP1	OPAMP2/4
PA8					1
PA9					2
PB0	15	OPAMP2/OPAMP3	OPAMP3/12
PB1	12		1
PB2		12
PB11	14	14			OPAMP4
PB12	11			OPAMP6/3
PB13		OPAMP3	OPAMP3/5	OPAMP6	OPAMP4
PB14	5	OPAMP2		4	OPAMP5
PB15		15		5
PC0	6	6
PC1	7	7
PC2	8	8
PC3	9	9			OPAMP5
PC4		5
PC5		11
PD10			7	7	7
PD11			8	8	OPAMP4/8
PD12			9	9	OPAMP5/9
PD13			10	10	10
PD14		OPAMP2	11	11	11
PD8				12	12
PD9				OPAMP6/13	13
PE7			4
PE8			6	6	6
PE9			2
PE10			14	14	14
PE11			15	15	15
PE12			16	16	16
PE13			3
PE14				1
PE15				2
PF0	10
PF1		10

Function Documentation

core_ADC_init()

bool core_ADC_init

(

ADC_TypeDef *

adc

)

Initialize an ADC module, including its clock. Also performs calibration. GPIO ports are not initialized.

Parameters

adc	The ADC module to initialize

Return values

0	if adc is not a valid ADC module or if the ADC fails to initialize
1	otherwise.

core_ADC_read_channel()

bool core_ADC_read_channel	(	GPIO_TypeDef *	port,
		uint32_t	pin,
		uint16_t *	result )

Read the value of an analog input as a value between 0 and 4095.

Parameters

port	GPIO port of the pin to be read (GPIOx)
pin	Pin number of the pin to be read (GPIO_PIN_x)
result	Location to which the result should be stored

Return values

0	if the given pin is not an analog input or if the corresponding ADC module is not initialized or if an error occurs while reading,
1	otherwise

core_ADC_setup_pin()

bool core_ADC_setup_pin	(	GPIO_TypeDef *	port,
		uint32_t	pin,
		uint8_t	opamp )

Set up a pin as an analog input.

Parameters

port	GPIO port (GPIOx)
pin	GPIO pin (GPIO_PIN_x)
opamp	1 if the input should be routed through an opamp, 0 otherwise

Return values

1	if a configuration was found for the given pin
0	otherwise