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hall.c
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	/*
	* Copyright (C) 2017 EPFL-LSRO (Laboratoire de Systemes Robotiques).
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "hall.h"

	#define HALL_AMPLI_GAIN 1.1f
	#define HALL_VOLT_DIVIDER 0.5f

	AdcChannel hall_channel;

	/**
	* @brief Initialize the hall sensor driver.
	* @param channel: the ADC channel the hall sensor is wired to (0 or 1).
	*/
	void hall_Init(AdcChannel channel)
	{
	hall_channel = channel;
	}

	/**
	* @brief Return the Hall sensor output voltage.
	* @return The Hall sensor output voltage [V].
	*/
	float32_t hall_GetVoltage(void)
	{
	// Because of the analog stages between the Hall sensor output pin and the
	// ADC pin, a conversion is necessary to obtain the Hall output voltage.
	float32_t voltage = adc_GetChannelVoltage(hall_channel); // Voltage at the ADC pin.
	voltage = voltage / HALL_VOLT_DIVIDER; // Voltage between the Bessel filter and the voltage divider.
	voltage = (voltage - ADC_REF_VOLTAGE) / HALL_AMPLI_GAIN + ADC_REF_VOLTAGE; // Voltage at the Hall output pin.

	return voltage;
	}