/* This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
/** BusVoodoo global definitions and methods (code)
 *  @file busvoodoo_global.c
 *  @author King Kévin <kingkevin@cuvoodoo.info>
 *  @date 2018
 *  @note peripherals used: time @ref busvoodoo_led_timer
 */

/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // standard utilities
#include <string.h> // string utilities
#include <math.h> // math utilities

/* STM32 (including CM3) libraries */
#include <libopencm3/cm3/nvic.h> // interrupt handler
#include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/adc.h> // ADC utilities
#include <libopencm3/stm32/dac.h> // DAC utilities
#include <libopencm3/stm32/timer.h> // timer utilities

/* own libraries */
#include "global.h" // board definitions
#include "menu.h" // command definitions
#include "print.h" // print utilities
#include "busvoodoo_global.h" // BusVoodoo definitions

/** @defgroup busvoodoo_led_timer timer used to blink LED
 *  @{
 */
#define BUSVOODOO_LED_TIMER 5 /**< timer peripheral */
/** @} */

/** blue LED status */
static volatile bool busvoodoo_global_led_blue = false;
/** red LED status */
static volatile bool busvoodoo_global_led_red = false;

/** hardware version voltages, calculated from divider ratios, starting with version A */
static const float busvoodoo_version_voltages[] = {100.0/(10.0+100.0)*3.3}; // version A start with revision 27

const char* busvoodoo_global_pinout_io[10] = {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL};
const char* busvoodoo_global_pinout_rscan[5] = {NULL, NULL, NULL, NULL, NULL};

const char* busvoodoo_io_names[13] = {"I2C_SMBA/SPI_NSS/I2S_WS/UART1_CK", "SDIO_CMD", "UART1_CTS/SPI_SCK/I2S_CK", "SDIO_D3/UART2_RX", "I2C_SDA/UART1_RX", "SDIO_D0", "SPI_MOSI/I2S_SD", "SDIO_CK", "I2C_SCL/UART1_TX", "SDIO_D1", "I2S_MCK", "UART1_RTS/SPI_MISO", "SDIO_D2/UART2_TX"};
const uint32_t busvoodoo_io_ports[13] = {GPIOB, GPIOD, GPIOB, GPIOC, GPIOB, GPIOC, GPIOB, GPIOC, GPIOB, GPIOC, GPIOC, GPIOB, GPIOC};
const uint32_t busvoodoo_io_pins[13] = {GPIO12, GPIO2, GPIO13, GPIO11, GPIO11, GPIO8, GPIO15, GPIO12, GPIO10, GPIO9, GPIO6, GPIO14, GPIO10};
const uint8_t busvoodoo_io_groups[13] = {6, 6, 4, 4, 1, 1, 5, 5, 2, 2, 3, 3, 3};

bool busvoodoo_full = false;
char busvoodoo_version = '0';
char busvoodoo_global_string[64];

void busvoodoo_setup(void)
{
	// enable all GPIO domains since we use pins on all ports
	rcc_periph_clock_enable(RCC_GPIOA); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_GPIOB); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_GPIOC); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_GPIOD); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_AFIO); // enable clock for alternate function (for communication)
	busvoodoo_safe_state(); // put pins in safe state (for common light version)

	// check if this BusVoodoo is a full flavor
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_HV_CHANNEL)); // enable clock for GPIO domain for HV channel
	gpio_set(ADC12_IN_PORT(BUSVOODOO_HV_CHANNEL), ADC12_IN_PIN(BUSVOODOO_HV_CHANNEL)); // pull ADC HV high
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_HV_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, ADC12_IN_PIN(BUSVOODOO_HV_CHANNEL)); // set HV channel as digital input with pull-up capabilities
	// on a full version (fully populated board) the ADC HV signal will be pulled low
	if (gpio_get(ADC12_IN_PORT(BUSVOODOO_HV_CHANNEL), ADC12_IN_PIN(BUSVOODOO_HV_CHANNEL))) { // check is ADC HV is pulled low
		busvoodoo_full = false;
	} else {
		busvoodoo_full = true;
		busvoodoo_safe_state(); // also put the full version pins in safe state
	}

	// setup ADC to measure the 5V, 3.3V, LV, and HV power rails voltages, and hardware version channel
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_5V_CHANNEL)); // enable clock for GPIO domain for 5V channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_5V_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_5V_CHANNEL)); // set 5V channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_3V3_CHANNEL)); // enable clock for GPIO domain for 3.3V channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_3V3_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_3V3_CHANNEL)); // set 3.3V channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_LV_CHANNEL)); // enable clock for GPIO domain for LV channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_LV_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_LV_CHANNEL)); // set LV channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_HV_CHANNEL)); // enable clock for GPIO domain for HV channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_HV_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_HV_CHANNEL)); // set HV channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_HW_VERSION_CHANNEL)); // enable clock for GPIO domain for hardware version channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_HW_VERSION_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_HW_VERSION_CHANNEL)); // set hardware version channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC1); // enable clock for ADC domain
	adc_power_off(ADC1); // switch off ADC while configuring it
	adc_disable_scan_mode(ADC1); // ensure scan mode is disabled
	adc_disable_discontinuous_mode_regular(ADC1); // ensure discontinuous mode is not used
	adc_set_single_conversion_mode(ADC1); // ensure continuous mode is not used (that's not the same as discontinuous)
	adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR_SMP_28DOT5CYC); // use 28.5 cycles to sample (long enough to be stable)
	adc_enable_temperature_sensor(); // enable internal voltage reference
	adc_power_on(ADC1); // switch on ADC
	sleep_us(1); // wait t_stab for the ADC to stabilize
	adc_reset_calibration(ADC1); // remove previous non-calibration
	adc_calibrate(ADC1); // calibrate ADC for less accuracy errors

	// find out version of the board
	gpio_set_mode(GPIO(BUSVOODOO_HW_VERSION_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, GPIO(BUSVOODOO_HW_VERSION_PIN)); // use pull up and down to check if a voltage divider is present on the pin
	gpio_set(GPIO(BUSVOODOO_HW_VERSION_PORT), GPIO(BUSVOODOO_HW_VERSION_PIN)); // pull up
	bool version_up = (0!=gpio_get(GPIO(BUSVOODOO_HW_VERSION_PORT), GPIO(BUSVOODOO_HW_VERSION_PIN))); // check if the signal is still up
	gpio_clear(GPIO(BUSVOODOO_HW_VERSION_PORT), GPIO(BUSVOODOO_HW_VERSION_PIN)); // pull down
	bool version_down = (0==gpio_get(GPIO(BUSVOODOO_HW_VERSION_PORT), GPIO(BUSVOODOO_HW_VERSION_PIN))); // check if the signal is still down
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_HW_VERSION_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_HW_VERSION_CHANNEL)); // put back to analog input
	// get version
	if (version_up && version_down) { // no voltage divider on pin
		busvoodoo_version = '0'; // the pin is floating only for version 0 (= revision 18)
	} else { // voltage divider on pin
		float version_voltage = busvoodoo_vreg_get(BUSVOODOO_HW_VERSION_CHANNEL); // measure hardware version voltage
		for (uint8_t i=0; i<LENGTH(busvoodoo_version_voltages); i++) { // go through expected version voltages
			if (version_voltage>busvoodoo_version_voltages[i]-0.2 && version_voltage<busvoodoo_version_voltages[i]+0.2) { // verify if voltage matches
				busvoodoo_version = 'A'+i; // remember version name for matching voltage
				break; // stop searching
			}
		}
	}

	// setup DAC to control LV and HV voltage outputs
	gpio_set_mode(GPIO(BUSVOODOO_LVCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_LVCTL_PIN)); // set LV pin as analog (the DAC will use it as output)
	rcc_periph_clock_enable(RCC_DAC); // enable clock for DAC domain
	dac_disable(BUSVOODOO_LVCTL_CHANNEL); // disable output to configure it properly
	dac_buffer_enable(BUSVOODOO_LVCTL_CHANNEL); // enable output buffer to be able to drive larger loads (should be per default)
	if (busvoodoo_full) {
		gpio_set_mode(GPIO(BUSVOODOO_HVCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_HVCTL_PIN)); // set HV pin as analog (the DAC will use it as output)
		dac_disable(BUSVOODOO_HVCTL_CHANNEL); // disable output to configure it properly
		dac_buffer_enable(BUSVOODOO_HVCTL_CHANNEL); // enable output buffer to be able to drive larger loads (should be per default)
	}
	dac_set_trigger_source(DAC_CR_TSEL1_SW); // use software to trigger the voltage change
	dac_set_trigger_source(DAC_CR_TSEL2_SW); // use software to trigger the voltage change

	// enable timer for LED blinking
	rcc_periph_clock_enable(RCC_TIM(BUSVOODOO_LED_TIMER)); // enable clock for timer domain
	timer_reset(TIM(BUSVOODOO_LED_TIMER)); //  reset timer configuration
	timer_set_mode(TIM(BUSVOODOO_LED_TIMER), TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP); // configure timer to up counting mode
	timer_set_prescaler(TIM(BUSVOODOO_LED_TIMER), (rcc_ahb_frequency/2000)-1); // set prescaler to have 2kHz ticks (the prescaler is not large enough for 1kHz ticks)
	timer_set_period(TIM(BUSVOODOO_LED_TIMER), 0xffff); // set period to maximum
	nvic_enable_irq(NVIC_TIM_IRQ(BUSVOODOO_LED_TIMER)); // enable interrupts for this timer
}

void busvoodoo_safe_state(void)
{
	// disable voltage outputs
	gpio_set(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO(BUSVOODOO_VOUTEN_PIN)); // disable 5V and 3.3V output on connector
	gpio_set_mode(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_VOUTEN_PIN)); // set pin as output (open-drain pulled high to disable the pMOS)
	gpio_clear(GPIO(BUSVOODOO_LVEN_PORT), GPIO(BUSVOODOO_LVEN_PIN)); // disable LV voltage regulator
	gpio_set_mode(GPIO(BUSVOODOO_LVEN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(BUSVOODOO_LVEN_PIN)); // set pin as output (push-pull, pulled low for safety)
	gpio_set(GPIO(BUSVOODOO_HVEN_PORT), GPIO(BUSVOODOO_HVEN_PIN)); // disable HV voltage regulator
	gpio_set_mode(GPIO(BUSVOODOO_HVEN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_HVEN_PIN)); // set pin as output (open-drain pulled high to disable the pMOS)

	// set DAC channel back to analog
	gpio_set_mode(GPIO(BUSVOODOO_LVCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_LVCTL_PIN)); // set LV pin as analog
	gpio_set_mode(GPIO(BUSVOODOO_HVCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_HVCTL_PIN)); // set HV pin as analog

	// disable embedded pull-ups
	gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON, 0); // disable JTAG (but keep SWD) so to use the underlying GPIOs (PA15, PB3, PB4)
	gpio_set(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO(BUSVOODOO_5VPULLUP_PIN)); // set pin high to disable 5V embedded pull-up
	gpio_set_mode(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_5VPULLUP_PIN)); // set pin as output (open-drain pulled high to disable the pMOS)
	gpio_set(GPIO(BUSVOODOO_OEPULLUP_PORT), GPIO(BUSVOODOO_OEPULLUP_PIN)); // set pin high to disable embedded pull-up bus switch
	gpio_set_mode(GPIO(BUSVOODOO_OEPULLUP_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_OEPULLUP_PIN)); // set pin as output (open-drain pulled high to disable the bus switch)

	// disable all signal I/O outputs
	for (uint8_t pin=0; pin<LENGTH(busvoodoo_io_ports) && pin<LENGTH(busvoodoo_io_pins); pin++) {
		gpio_set_mode(busvoodoo_io_ports[pin], GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, busvoodoo_io_pins[pin]); // set pin back to input (floating)
	}

	if (busvoodoo_full) {
		// disable RS-232 signals
		gpio_set_mode(GPIO(BUSVOODOO_RS232_TX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_TX_PIN)); // set pin to floating
		gpio_set_mode(GPIO(BUSVOODOO_RS232_RX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_RX_PIN)); // set pin to floating
		gpio_set_mode(GPIO(BUSVOODOO_RS232_RTS_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_RTS_PIN)); // set pin to floating
		gpio_set_mode(GPIO(BUSVOODOO_RS232_CTS_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_CTS_PIN)); // set pin to floating
		gpio_set(GPIO(BUSVOODOO_RS232_EN_PORT), GPIO(BUSVOODOO_RS232_EN_PIN)); // set high to disable receiver
		gpio_set_mode(GPIO(BUSVOODOO_RS232_EN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_RS232_EN_PIN)); // use external pull-up resistor to set high by default
		gpio_clear(GPIO(BUSVOODOO_RS232_SHDN_PORT), GPIO(BUSVOODOO_RS232_SHDN_PIN)); // set low to disable transmitter
		gpio_set_mode(GPIO(BUSVOODOO_RS232_SHDN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(BUSVOODOO_RS232_SHDN_PIN)); // there is also an external pull-down resistor to disable per default

		// disable RS-485 signals (RS and TX are shared with RS-232)
		gpio_set(GPIO(BUSVOODOO_RS485_RE_PORT), GPIO(BUSVOODOO_RS485_RE_PIN)); // set high to disable receiver
		gpio_set_mode(GPIO(BUSVOODOO_RS485_RE_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_RS485_RE_PIN)); // use external pull-up resistor to set high by default
		gpio_clear(GPIO(BUSVOODOO_RS485_DE_PORT), GPIO(BUSVOODOO_RS485_DE_PIN)); // set low to disable transmitter
		gpio_set_mode(GPIO(BUSVOODOO_RS485_DE_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(BUSVOODOO_RS485_DE_PIN)); // there is also an external pull-down resistor to disable per default
		gpio_set_mode(GPIO(BUSVOODOO_RS485_TX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS485_TX_PIN)); // set pin to floating
		gpio_set_mode(GPIO(BUSVOODOO_RS485_RX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS485_RX_PIN)); // set pin to floating

#if BUSVOODOO_HARDWARE_VERSION!=0 
		// disable CAN transceiver and signals (put back to input floating)
		gpio_set_mode(GPIO(BUSVOODOO_CAN_TX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_CAN_TX_PIN)); // set pin to floating
		gpio_set_mode(GPIO(BUSVOODOO_CAN_RX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_CAN_RX_PIN)); // set pin to floating
		gpio_set(GPIO(BUSVOODOO_CAN_EN_PORT), GPIO(BUSVOODOO_CAN_EN_PIN)); // set high to power off transceiver
		gpio_set_mode(GPIO(BUSVOODOO_CAN_EN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_CAN_EN_PIN)); // use external pull-up resistor to set high by default
#endif
	}
}

bool busvoodoo_vout_switch(bool on)
{
	if (on) { // we need to switch on Vout
		gpio_clear(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO(BUSVOODOO_VOUTEN_PIN)); // enable Vout
	} else {
		gpio_set(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO(BUSVOODOO_VOUTEN_PIN)); // disable Vout
	}

	bool to_return = true;
	sleep_ms(1); // wait a bit for voltage to settle
	float voltage = busvoodoo_vreg_get(BUSVOODOO_5V_CHANNEL); // get 5V power rail voltage
	if (voltage<4.0 || voltage>5.5) {
		to_return = false; // voltage output is not ok
	}
	voltage = busvoodoo_vreg_get(BUSVOODOO_3V3_CHANNEL); // get 3.3V power rail voltage
	if (voltage<3.0 || voltage>3.6) {
		to_return = true; // voltage output is not ok
	}
	return to_return;
}

float busvoodoo_vreg_get(uint8_t channel)
{
	if (channel!=BUSVOODOO_5V_CHANNEL && channel!=BUSVOODOO_3V3_CHANNEL && channel!=BUSVOODOO_LV_CHANNEL && channel!=BUSVOODOO_HV_CHANNEL && channel!=BUSVOODOO_HW_VERSION_CHANNEL) { // check channel
		return NAN;
	}

	// start by reading the internal voltage
	uint8_t channels[1] = {ADC_CHANNEL17}; // voltages to convert: internal
	adc_set_regular_sequence(ADC1, LENGTH(channels), channels); // set channel to convert
	ADC_SR(ADC1) = 0; // reset flags
	adc_start_conversion_direct(ADC1); // start conversion (without using trigger)
	while (!adc_eoc(ADC1)); // wait until conversion finished
	uint16_t internal_value = adc_read_regular(ADC1); // read voltage value (clears flag)

	// read desired voltage
	switch (channel) {
		case BUSVOODOO_5V_CHANNEL:
			channels[0] = ADC_CHANNEL(BUSVOODOO_5V_CHANNEL);
			break;
		case BUSVOODOO_3V3_CHANNEL:
			channels[0] = ADC_CHANNEL(BUSVOODOO_3V3_CHANNEL);
			break;
		case BUSVOODOO_LV_CHANNEL:
			channels[0] = ADC_CHANNEL(BUSVOODOO_LV_CHANNEL);
			break;
		case BUSVOODOO_HV_CHANNEL:
			channels[0] = ADC_CHANNEL(BUSVOODOO_HV_CHANNEL);
			break;
		case BUSVOODOO_HW_VERSION_CHANNEL:
			channels[0] = ADC_CHANNEL(BUSVOODOO_HW_VERSION_CHANNEL);
			break;
		default: // unknown channel
			return NAN;
	}
	adc_set_regular_sequence(ADC1, LENGTH(channels), channels); // set channel to convert
	ADC_SR(ADC1) = 0; // reset flags
	adc_start_conversion_direct(ADC1); // start conversion (without using trigger)
	while (!adc_eoc(ADC1)); // wait until conversion finished
	uint16_t desired_value = adc_read_regular(ADC1); // read voltage value (clears flag)

	// calculate desired voltage
	float to_return = NAN; // voltage to return
	switch (channel) { // get converted value and calculate according to the voltage divider on this channel
		case BUSVOODOO_5V_CHANNEL:
			to_return = desired_value/(10.0/(10.0+10.0));
			break;
		case BUSVOODOO_3V3_CHANNEL:
			to_return = desired_value/(10.0/(10.0+10.0));
			break;
		case BUSVOODOO_LV_CHANNEL:
			to_return = desired_value/(10.0/(10.0+10.0));
			break;
		case BUSVOODOO_HV_CHANNEL:
			to_return = desired_value/(1.5/(10.0+1.5));
			break;
		case BUSVOODOO_HW_VERSION_CHANNEL:
			to_return = desired_value;
			break;
		default: // unknown channel
			to_return = NAN;
			break;
	}
	if (!isnan(to_return)) {
		to_return *= 1.2/internal_value; // calculate voltage from converted values using internal 1.2V voltage reference
	}
	return to_return;
}

float busvoodoo_lv_set(float voltage)
{
	float volt = NAN; // common variable for voltages
	if (voltage<=0.3) { // disable voltage regulator
		gpio_clear(GPIO(BUSVOODOO_LVEN_PORT), GPIO(BUSVOODOO_LVEN_PIN)); // disable LV voltage regulator
		dac_disable(BUSVOODOO_LVCTL_CHANNEL); // disable LV control
	} else { // enable voltage regulator
		if (voltage>4.85) { // use the 5V directly
			gpio_clear(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO(BUSVOODOO_5VPULLUP_PIN)); // put 5V on LV line
		} else { // use adjustable voltage regulator (5.0V rail minus LDO and diodes)
			gpio_set(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO(BUSVOODOO_5VPULLUP_PIN)); // disable 5V input
			volt = busvoodoo_vreg_get(BUSVOODOO_3V3_CHANNEL); // get reference voltage
			if (isnan(voltage)) {
				return NAN;
			}
			uint16_t dac_set = BUSVOODOO_LV_SET(voltage)/volt*4095; // DAC value corresponding to the voltage
			dac_load_data_buffer_single(dac_set, RIGHT12, BUSVOODOO_LVCTL_CHANNEL); // set output so the voltage regulator is set to 2.5V
			dac_software_trigger(BUSVOODOO_LVCTL_CHANNEL); // transfer the value to the DAC
			dac_enable(BUSVOODOO_LVCTL_CHANNEL); // enable DAC
			gpio_set(GPIO(BUSVOODOO_LVEN_PORT), GPIO(BUSVOODOO_LVEN_PIN)); // enable LV voltage regulator
		}
	}
	sleep_ms(50); // let voltage settle
	volt = busvoodoo_vreg_get(BUSVOODOO_LV_CHANNEL); // get LV voltage to return

	return volt; // return measured voltage
}

float busvoodoo_hv_set(float voltage)
{
	if (!busvoodoo_full) { // the HV voltage regulator is only present on the full version
		return NAN;
	}

	float volt = NAN; // common variable for voltages
	if (voltage<3.29) { // disable voltage regulator
		gpio_set(GPIO(BUSVOODOO_HVEN_PORT), GPIO(BUSVOODOO_HVEN_PIN)); // disable HV voltage regulator
		dac_disable(BUSVOODOO_HVCTL_CHANNEL); // disable HV control
	} else {
		if (voltage>24.0) { // enforce upper voltage limit (diodes limit is 30V, ADC input limit is 25V)
			voltage = 24.0;
		}
		volt = busvoodoo_vreg_get(BUSVOODOO_3V3_CHANNEL); // get reference voltage
		if (isnan(voltage)) {
			return NAN;
		}
		uint16_t dac_set = BUSVOODOO_HV_SET(voltage)/volt*4095; // DAC value corresponding to the voltage
		dac_load_data_buffer_single(dac_set, RIGHT12, BUSVOODOO_HVCTL_CHANNEL); // set output so the voltage regulator is set to desired output voltage
		dac_software_trigger(BUSVOODOO_HVCTL_CHANNEL); // transfer the value to the DAC
		dac_enable(BUSVOODOO_HVCTL_CHANNEL); // enable DAC
		gpio_clear(GPIO(BUSVOODOO_HVEN_PORT), GPIO(BUSVOODOO_HVEN_PIN)); // enable HV voltage regulator
	}
	sleep_ms(100); // let the voltage regulator start and voltage settle
	volt = busvoodoo_vreg_get(BUSVOODOO_HV_CHANNEL); // get HV voltage

	return volt; // return measured voltage
}

float busvoodoo_embedded_pullup(bool on)
{
	if (on) { // enable embedded pull-ups
		gpio_clear(GPIO(BUSVOODOO_OEPULLUP_PORT), GPIO(BUSVOODOO_OEPULLUP_PIN)); // switch on embedded pull-ups
	} else { // disable embedded pull-ups
		gpio_set(GPIO(BUSVOODOO_OEPULLUP_PORT), GPIO(BUSVOODOO_OEPULLUP_PIN)); // switch off embedded pull-up
	}
	return busvoodoo_vreg_get(BUSVOODOO_LV_CHANNEL); // set voltage on adjustable voltage regulator to be used by the embedded pull-ups
}

/** update LED status according to LED flags */
static void busvoodoo_led_update(void)
{
	if (busvoodoo_global_led_blue && busvoodoo_global_led_red) { // both LEDs should be on
		led_blink(0.01, 0.5); // enable both LEDs (alternating at 100Hz)
	} else if (busvoodoo_global_led_blue) { // only blue LED should be on
		led_blue(); // enable only blue LED
	} else if (busvoodoo_global_led_red) { // only red LED should be on
		led_red(); // enable only red LED
	} else { // no LED should be on
		led_off(); // disable both LEDs
	}
}

void busvoodoo_led_blue_pulse(uint16_t ms)
{
	timer_disable_counter(TIM(BUSVOODOO_LED_TIMER)); // disable counter while changing LEDs to avoid coherence errors (at the cost of time precision)	
	if (ms>UINT16_MAX/2) { // enforce maximum
		ms = UINT16_MAX/2;
	}

	if (0==ms) { // disable LED
		busvoodoo_global_led_blue = false; // remember we disabled the blue LED
	} else {	
		busvoodoo_global_led_blue = true; // remember the blue LED should be on
		timer_set_oc_value(TIM(BUSVOODOO_LED_TIMER), TIM_OC1, timer_get_counter(TIM(BUSVOODOO_LED_TIMER))+ms*2); // use capture 1 to set LED timer
		timer_clear_flag(TIM(BUSVOODOO_LED_TIMER), TIM_SR_CC1IF); // clear flag before enabling
		timer_enable_irq(TIM(BUSVOODOO_LED_TIMER), TIM_DIER_CC1IE); // enable capture 1 for blue LED
	}
	busvoodoo_led_update(); // update LED status
	timer_enable_counter(TIM(BUSVOODOO_LED_TIMER)); // re-enable timer
}

void busvoodoo_led_red_pulse(uint16_t ms)
{
	timer_disable_counter(TIM(BUSVOODOO_LED_TIMER)); // disable counter while changing LEDs to avoid coherence errors (at the cost of time precision)	
	if (ms>UINT16_MAX/2) { // enforce maximum
		ms = UINT16_MAX/2;
	}

	if (0==ms) { // disable LED
		busvoodoo_global_led_red = false; // remember we disabled the blue LED
	} else {	
		busvoodoo_global_led_red = true; // remember the blue LED should be on
		timer_set_oc_value(TIM(BUSVOODOO_LED_TIMER), TIM_OC2, timer_get_counter(TIM(BUSVOODOO_LED_TIMER))+ms*2); // use capture 1 to set LED timer
		timer_clear_flag(TIM(BUSVOODOO_LED_TIMER), TIM_SR_CC2IF); // clear flag before enabling
		timer_enable_irq(TIM(BUSVOODOO_LED_TIMER), TIM_DIER_CC2IE); // enable capture 2 for red LED
	}
	busvoodoo_led_update(); // update LED status
	timer_enable_counter(TIM(BUSVOODOO_LED_TIMER)); // re-enable timer
}

bool busvoodoo_global_actions(char* actions, bool perform, bool (*action_handler)(const char* action, uint32_t repetition, bool perform))
{
	char* action_start = actions; // start of the current action
	bool last_action = false; // is the current action the last one
	while ('\0'!=*action_start && !last_action) {
		// find end of action
		char* action_end = action_start+1;
		if ('"'==*action_start || '\''==*action_start) { // start of string
			while ('\0'!=*action_end && *action_end!=*action_start) {
				action_end++;
			}
			if (*action_end!=*action_start) { // action not ended correctly
				return false;
			}
			action_end++; // go the end of action
		} else { // just look for a separation
			while ('\0'!=*action_end && ':'!=*action_end && ' '!=*action_end && ','!=*action_end) {
				action_end++;
			}
		}
		// find start of next action
		char *separation = action_end; // position of separation to next action
		while ('\0'!=*separation && ' '!=*separation && ','!=*separation) { // find separation or end
			separation++;
		}
		if ('\0'==*separation) {
			last_action = true; // remember we reached the end of the string
		} else {
			*separation = '\0'; // end the action to form a string
		}
		// get multiplier
		uint32_t multiplier = 1; // the number of times the action should be performed
		if (separation>action_end) { // there is something after the action
			if (':'==*action_end) { // multiplier sign found
				if (separation==action_end+1) { // no digit present
					return false; // malformed action
				}
				for (char* digit=action_end+1; digit<separation; digit++) { // check if all the characters are digits
					if (*digit<'0' || *digit>'9') { // not a digit
						return false; // malformed string
					}
				}
				multiplier = strtol(action_end+1, NULL, 10); // parse multiplier number
			} else { // unknown sign after action
				return false; // malformed action
			}
		}
		// perform action
		*action_end = '\0'; // end action string
		if (!(*action_handler)(action_start, multiplier, perform)) { // perform action
			return false; // action if malformed
		}
		// go to next action
		if (!last_action) {
			action_start = separation+1;
		}
	}
	return true; // all went well
}

/* command handlers */

/** switch 3V3 and 5V power rails on/off
 *  @param[in] argument string: "on" to switch on, "off" to switch off, NULL to get status
 */
static void busvoodoo_global_power(void* argument)
{
	float voltage;
	if (NULL==argument || 0==strlen(argument)) {
		if (gpio_get(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO(BUSVOODOO_VOUTEN_PIN))) { // check if power rails are switch on (enable low)
			goto power_off;
		} else {
			goto power_on;
		}
	} else if (0==strcmp(argument, "on")) {
		if (busvoodoo_vout_switch(true)) { // switch power rail on
			printf("power rails switched on\n");
		} else {
			printf("power rails switched on but malfunctioning\n");
		}
power_on:
		voltage = busvoodoo_vreg_get(BUSVOODOO_5V_CHANNEL); // get 5V power rail voltage
		printf("5V power rail: %.2fV\n", voltage);
		voltage = busvoodoo_vreg_get(BUSVOODOO_3V3_CHANNEL); // get 3.3V power rail voltage
		printf("3V3 power rail: %.2fV\n", voltage);
	} else if (0==strcmp(argument, "off")) {
		busvoodoo_vout_switch(false); // switch power rail off
		printf("power rails switched off\n");
power_off:
		printf("5V power rail: off\n");
		printf("3V3 power rail: off\n");
	} else {
		printf("option malformed: %s\n", argument);
	}
}

/** set lV linear drop-out voltage regulator voltage
 *  @param[in] argument voltage to set (0 to switch off, NULL to get voltage)
 */
static void busvoodoo_global_lv(void* argument)
{
	if (NULL==argument) {
		if (!gpio_get(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO(BUSVOODOO_5VPULLUP_PIN))) { // 5V input enabled
			printf("5V power rail used");
		} else if (gpio_get(GPIO(BUSVOODOO_LVEN_PORT), GPIO(BUSVOODOO_LVEN_PIN))) { // LV voltage regulator used
			printf("adjustable voltage regulator used");
		} else {
			printf("external voltage input");
		}
		float voltage = busvoodoo_vreg_get(BUSVOODOO_LV_CHANNEL); // get LV voltage
		// print LV voltage
		if (voltage < 0.1) {
			printf(": 0.00V\n");
		} else {
			printf(": %.2fV\n", voltage);
		}
	} else {
		double voltage = *((double*)argument); // get desired voltage
		if (0==voltage) {
			printf("LV rail switched off");
		} else {
			printf("LV rail set to %.2fV", voltage);
		}
		voltage = busvoodoo_lv_set(voltage); // set LV voltage
		// print LV voltage
		if (voltage < 0.1) {
			printf(": 0.00V\n");
		} else {
			printf(": %.2fV\n", voltage);
		}
	}
}

/** set HV step-up voltage regulator voltage
 *  @param[in] argument voltage to set (0 to switch off, NULL to get voltage)
 */
static void busvoodoo_global_hv(void* argument)
{
	if (!busvoodoo_full) {
		printf("function not available on BusVoodoo light");
		return;
	}
	if (NULL==argument) {
		printf("high voltage regulator switched %s: ", gpio_get(GPIO(BUSVOODOO_HVEN_PORT), GPIO(BUSVOODOO_HVEN_PIN)) ? "off" : "on");
		float voltage = busvoodoo_vreg_get(BUSVOODOO_HV_CHANNEL); // get HV voltage
		// print LV voltage
		if (voltage < 0.1) {
			printf("0.00V\n");
		} else {
			printf("%.2fV\n", voltage);
		}
	} else {
		double voltage = *((double*)argument); // get desired voltage
		printf("high voltage rail ");
		if (voltage<=3.3) {
			printf("switched off");
		} else {
			printf("set to %.2fV", voltage);
		}
		voltage = busvoodoo_hv_set(voltage); // set HV voltage
		// print HV voltage
		if (voltage < 0.1) {
			printf(": 0.00V\n");
		} else {
			printf(": %.2fV\n", voltage);
		}
	}
}

/** display I/O and RS/CAN connector pinouts
 *  @param[in] argument not used
 */
static void busvoodoo_global_pinout(void* argument)
{
	(void)argument; // argument is not used
	bool no_pinout = true; // it no pinout has been displays

	// display RS/CAN connector pinout
	if (busvoodoo_full) { // only display on full version of the board
		bool pin_used = false; // if no pins are used
		for (uint8_t i=0; i<LENGTH(busvoodoo_global_pinout_rscan); i++) { // verify if one of the pins is used
			pin_used |= (NULL!=busvoodoo_global_pinout_rscan[i]); // verify if pin is used
		}
		if (pin_used) {
			// count the space used to display the pins
			uint8_t space = 0; // no integer overflow protected (it's only cosmetic)
			for (uint8_t i=0; i<LENGTH(busvoodoo_global_pinout_rscan); i++) {
				if (NULL==busvoodoo_global_pinout_rscan[i]) {
					space += 1; // only x will be shown
				} else {
					space += strlen(busvoodoo_global_pinout_rscan[i]); // add size of pin name
				}
			}
			space += LENGTH(busvoodoo_global_pinout_rscan)-1; // add the spaces between the names
			// display pinout
			printf("RS/CAN connector pinout:\n");
			// display top line
			printf("+");
			for (uint8_t i=0; i<space; i++) {
				printf("-");
			}
			printf("+\n");
			// display pin names
			printf("|");
			for (int8_t i=LENGTH(busvoodoo_global_pinout_rscan)-1; i>=0; i--) {
				if (NULL==busvoodoo_global_pinout_rscan[i]) {
					printf("x"); // x stands for pin not used
				} else {
					printf("%s", busvoodoo_global_pinout_rscan[i]); // print pin name
				}
				if (i>0) {
					printf(" "); // print space between the pin names
				}
			}
			printf("|\n");
			// display bottom line
			printf("+");
			for (uint8_t i=0; i<space; i++) {
				printf("-");
			}
			printf("+\n");
			no_pinout = false; // remember a pinout has been shown
		}
	}

	// display I/O connector pinout
	bool pin_used = false; // if no pins are used
	for (uint8_t i=0; i<LENGTH(busvoodoo_global_pinout_io); i++) { // verify if one of the pins is used
		pin_used |= (NULL!=busvoodoo_global_pinout_io[i]); // verify if pin is used
	}
	if (pin_used) {
		// count the space used to display the pins (no integer overflow protected, it's only cosmetic)
		uint8_t spaces[5] = {0}; // maximum spaces used by top and bottom pins
		for (uint8_t i=0; i<LENGTH(spaces); i++) {
			if (NULL==busvoodoo_global_pinout_io[i*2]) {
				spaces[i] = 1; // only x will be shown
			} else {
				spaces[i] = strlen(busvoodoo_global_pinout_io[i*2]); // remember size of pin name
			}
			if (NULL==busvoodoo_global_pinout_io[i*2+1]) {
				if (spaces[i]<1) {
					spaces[i] = 1; // only x will be shown
				}
			} else {
				if (spaces[i]<strlen(busvoodoo_global_pinout_io[i*2+1])) {
					spaces[i] = strlen(busvoodoo_global_pinout_io[i*2+1]); // remember bigger size of pin name
				}
			}
		}
		// display pinout
		printf("I/O connector pinout:\n");
		// display top line
		printf("+");
		for (uint16_t i=0; i<(uint16_t)(spaces[4]+spaces[3]+1); i++) {
			printf("-");
		}
		for (uint16_t i=0; i<(uint16_t)(spaces[2]+2); i++) {
			printf(" ");
		}
		for (uint16_t i=0; i<(uint16_t)(spaces[1]+spaces[0]+1); i++) {
			printf("-");
		}
		printf("+\n");
		// display top pin names
		printf("|");
		for (int8_t i=4; i>=0; i--) {
			if (NULL==busvoodoo_global_pinout_io[i*2]) {
				printf("x"); // x stands for pin not used
				for (int16_t j=0; j<spaces[i]-1; j++) {
					printf(" "); // pad to match to bottom pin
				}
			} else {
				printf("%s", busvoodoo_global_pinout_io[i*2]); // print pin name
				for (int16_t j=0; j+strlen(busvoodoo_global_pinout_io[i*2])<spaces[i]; j++) {
					printf(" "); // pad to match to bottom pin
				}
			}
			if (i>0) {
				printf(" "); // print space between the pin names
			}
		}
		printf("|\n");
		// display bottom pin names
		printf("|");
		for (int8_t i=4; i>=0; i--) {
			if (NULL==busvoodoo_global_pinout_io[i*2+1]) {
				printf("x"); // x stands for pin not used
				for (int16_t j=0; j<spaces[i]-1; j++) {
					printf(" "); // pad to match to bottom pin
				}
			} else {
				printf("%s", busvoodoo_global_pinout_io[i*2+1]); // print pin name
				for (int16_t j=0; j+strlen(busvoodoo_global_pinout_io[i*2+1])<spaces[i]; j++) {
					printf(" "); // pad to match to bottom pin
				}
			}
			if (i>0) {
				printf(" "); // print space between the pin names
			}
		}
		printf("|\n");
		// display bottom line
		printf("+");
		for (uint16_t i=0; i<spaces[4]+1+spaces[3]+1+spaces[2]+1+spaces[1]+1+spaces[0]; i++) {
			printf("-");
		}
		printf("+\n");
		no_pinout = false; // remember a pinout has been shown
	}

	// in case nothing has been displayed
	if (no_pinout) {
		printf("no pins are used\n");
	}
}

const struct menu_command_t busvoodoo_global_commands[] = {
	{
		.shortcut = 'p',
		.name = "pinout",
		.command_description = "show connector pinout",
		.argument = MENU_ARGUMENT_NONE,
		.argument_description = NULL,
		.command_handler = &busvoodoo_global_pinout,
	},
	{
		.shortcut = 'P',
		.name = "power",
		.command_description = "switch 3V3 and 5V power rails on/off, or read internal voltages",
		.argument = MENU_ARGUMENT_STRING,
		.argument_description = "[on|off]",
		.command_handler = &busvoodoo_global_power,
	},
	{
		.shortcut = 'L',
		.name = "LV",
		.command_description = "set voltage on low voltage power rail (0, 0.3-4.8, 5V), or read voltage on pin",
		.argument = MENU_ARGUMENT_FLOAT,
		.argument_description = "[voltage]",
		.command_handler = &busvoodoo_global_lv,
	},
};

const uint8_t busvoodoo_global_commands_nb = LENGTH(busvoodoo_global_commands);

const struct menu_command_t busvoodoo_global_full_commands[] = {
	{
		.shortcut = 'H',
		.name = "HV",
		.command_description = "set voltage on high voltage power rail (0, 3.3-24V), or read voltage on pin",
		.argument = MENU_ARGUMENT_FLOAT,
		.argument_description = "[voltage]",
		.command_handler = &busvoodoo_global_hv,
	},
};

const uint8_t busvoodoo_global_full_commands_nb = LENGTH(busvoodoo_global_full_commands);

/** interrupt service routine called on LED timeout */
void TIM_ISR(BUSVOODOO_LED_TIMER)(void)
{
	if (timer_get_flag(TIM(BUSVOODOO_LED_TIMER), TIM_SR_CC1IF)) { // blue LED timeout
		timer_clear_flag(TIM(BUSVOODOO_LED_TIMER), TIM_SR_CC1IF); // clear flag
		timer_disable_irq(TIM(BUSVOODOO_LED_TIMER), TIM_DIER_CC1IE); // disable capture 1 for blue LED
		busvoodoo_global_led_blue = false; // remember blue LED should be disabled
		busvoodoo_led_update(); // update LED status
	} else if (timer_get_flag(TIM(BUSVOODOO_LED_TIMER), TIM_SR_CC2IF)) { // red LED timeout
		timer_clear_flag(TIM(BUSVOODOO_LED_TIMER), TIM_SR_CC2IF); // clear flag
		timer_disable_irq(TIM(BUSVOODOO_LED_TIMER), TIM_DIER_CC2IE); // disable capture 2 for red LED
		busvoodoo_global_led_red = false; // remember red LED should be disabled
		busvoodoo_led_update(); // update LED status
	}
}
