《安富莱嵌入式周报》第284期：Matlab2022b发布，支持从 .NET 调用，耳机放大器，牛屎芯片替换，JSON可视化，开源的飞行软件和嵌入式系统框架

往期周报汇总地址：http://www.armbbs.cn/forum.php?mod=forumdisplay&fid=12&filter=typeid&typeid=104

视频教程更新：

GUI综合实战视频教程第1期：综合UI项目规划以及AppWizard和ThreadX GUIX初识（2022-09-24）

https://www.armbbs.cn/forum.php?mod=viewthread&tid=115615

视频版：

https://www.bilibili.com/video/BV1RT411T7PL

1、Matlab2022b发布，支持从 .NET 应用程序调用 MATLAB

https://ww2.mathworks.cn/product ... atest_features.html

详细更新如下：

2、FatFS作者ChaN老师分享的耳机放大器文章说明已经发布，包含固件源码

http://elm-chan.org/works/hpamp/report.html

代码：

/*-------------------------------------------------*/
/* Headphone Amplifier Controller    (C)ChaN, 2022 */
/*-------------------------------------------------*/
 
#include <avr/io.h>
#include <avr/sleep.h>
#include <avr/interrupt.h>
 
FUSES = {0x6A, 0xFD};                /* ATtiny13A fuses: Low, High */
 
 
#define BLV_LOW                2.3                /* Low battery threshold [volt] */
#define BLV_OFF                2.1                /* Shutdown threshold [volt] */
#define        MUL_VIN                0.333
#define        VREF                1.1
#define VOLT2AD(v)        ((uint16_t)(v * MUL_VIN * 1024 / VREF))
 
#define HOLD_TIME        50                /* Button hold time to trigger on/off (x10ms) */
 
 
#define        POWER_ENABLE()        PORTB |= _BV(3)
#define        POWER_DISABLE()        PORTB &= ~_BV(3)
#define        OUT_ENABLE()        PORTB |= _BV(0)
#define        OUT_DISABLE()        PORTB &= ~_BV(0)
#define        LED_ON()                PORTB |= _BV(2)
#define        LED_OFF()                PORTB &= ~_BV(2)
#define BUTTON                        (!(PINB & _BV(1)))
 
 
volatile uint8_t Stat;        /* Battery status: 0=empty, 1=low, 2=ok */
 
 
 
ISR(INT0_vect)                        /* Wake-up from sleep mode */
{
        GIMSK = 0;        /* Disable INT0 (on button down) */
}
 
 
 
ISR(TIM0_COMPA_vect)        /* 100Hz timer interrupt */
{
        uint8_t n;
        static uint8_t blink;
 
 
        n = Stat;
        if (n == 2 || (n == 1 && (++blink & 32))) {
                LED_ON();
        } else {
                LED_OFF();
        }
}
 
 
 
static void delay_10ms (void)
{
        set_sleep_mode(SLEEP_MODE_IDLE);        /* Set Idle mode */
        sleep_mode();
}
 
 
 
static uint8_t test_button (void)        /* b0:status, b1:trigger */
{
        static uint8_t btn;
 
 
        if (BUTTON) {
                if (btn < HOLD_TIME) {
                        if (++btn == HOLD_TIME) return 3;
                }
                return 1;
        } else {
                btn = 0;
                return 0;
        }
}
 
 
static void power_off_mode (void)
{
        uint8_t n;
 
 
        Stat = 0;        /* LED off */
        for (;;) {
                /* LED off, power off, headphone off */
                LED_OFF();
                OUT_DISABLE();
                POWER_DISABLE();
 
                /* Wait for button released (100ms) */
                for (n = 10; n; n--) {
                        delay_10ms();
                        if (test_button() != 0) n = 10;
                }
 
                /* Sleep and resume */
                TIMSK0 = 0;                                        /* Disable timer interrupt */
                cli();                                                /* Disable interrupts for critical operations */
                GIMSK = _BV(INT0);                        /* Enable button down interrupt (INT0) */
                set_sleep_mode(SLEEP_MODE_PWR_DOWN);        /* Set Power-Down mode*/
                sleep_enable();                                /* Enable sleep mode */
                sleep_bod_disable();                /* Disable BOD in sleep mode */
                sei();                                                /* Eneble interrupt to wake-up */
                sleep_cpu();                                /* Enter sleep mode */
 
                /*------ Sleeping ------*/
 
                sleep_disable();                        /* Disable sleep mode */
                TIMSK0 = _BV(OCIE0A);                /* Enable timer interrupt */
 
                /* Press and hold the button for HOLD_TIME to start */
                do {
                        delay_10ms();
                        n = test_button();
                } while (n == 1);
                if (n == 3) break;        /* Exit if the button was held for HOLD_TIME, or stay power off */
        }
 
        POWER_ENABLE();                /* Enable DC-DC converter */
        Stat = 2;                        /* LED on */
        for (n = 30; n; n--) delay_10ms();        /* 300ms */
        OUT_ENABLE();                /* Ebable headphone output */
}
 
 
 
static uint8_t battery_level (void)        /* Test battery status (2=ok, 1=low, 0=empty) */
{
        uint16_t adc;
 
 
        ADMUX = _BV(REFS0) | 2;                                        /* Select ADC2 with Vref = internal 1.1V */
        ADCSRA = _BV(ADEN)|_BV(ADSC)|_BV(ADIF)|0b011;        /* Enable ADC and start conversion */
        while (!(ADCSRA & _BV(ADIF))) ;                        /* Wait for EOC */
        adc = ADC;
        ADCSRA = 0;                                                                /* Disable ADC */
 
        if (adc < VOLT2AD(BLV_OFF)) return 0;        /* Empty? */
        if (adc < VOLT2AD(BLV_LOW)) return 1;        /* Low? */
        return 2;
}
 
 
 
int main (void)
{
        uint8_t btct, btlv;
 
 
        /* Initialize GPIOs */
        PORTB = 0b00000;                /* Initialize PORTB as: */
        DDRB  = 0b01101;                /* BP4=Vbat, PB3=Power, PB2=LED, PB1=Button, BP0=OutEnable */
        DIDR0 = 0b10000;                /* Disable digital input on PB4 */
 
        /* Enable TC0 in 100 Hz interval timer */
        OCR0A = F_CPU / 256 / 100 - 1;
        TCCR0A = _BV(WGM01);
        TCCR0B = 0b100;
        TIMSK0 = _BV(OCIE0A);
 
        sei();
 
        for (;;) {
                power_off_mode();        /* Power-off and wake-up */
 
                btct = btlv = 0;
                for (;;) {
                        delay_10ms();
                        if (test_button() == 3) break;        /* Test button */
                        btlv += battery_level();                /* Test battery level */
                        if (++btct == 50) {                                /* 50 times averaging */
                                if (btlv < 25) break;                /* Battery empty? */
                                Stat = btlv < 75 ? 1 : 2;        /* Battery ok or low? */
                                btct = btlv = 0;
                        }
                }
        }
}