10. Output Devices - Week 10¶

10.1. Assignments¶

Input Devices

group assignment

measure the power consumption of an output device individual assignment

add an output device to a microcontroller board you’ve designed, and program it to do something

10.2. Group Assignment¶

Group Page

For the Power Consumption I measured the current of one WS2812B LED to calculate, how much Ampere would run on my board below. There I limited the current to 100mA and set the Voltage to 3.3V which I wanted to operate them with in my board below.

IMAGE_WS_current

There I measured:

0.02A @ 3.3V

for one LED with color white.

I wanted to build 12 of those LEDs in my board and I wanted to use 2 of the Super Capacitors to power the board, here the energy and time calculation:

2x Super Conductors
each:
    - 10F
    - 3.8V

12x WS2812B
each:
    - 0.02A
    - 3.3V

Q = C * V = 10F * 3.8V
=> 38C == 38 As

For 1 LED:

2 * 38 As / 0.02A = 3800s == ca. 63min (-> a small pomodoro cycle :D)

For 12 LEDs:

2 * 38As / (12 * 0.02A) = 317s == ca. 5min

Also note that this is with full Brightness and white color, meaning if I change to another color and decrease the brightness, I should get more time :].

10.3. Individual Assignment¶

10.3.1. AT Tiny412 Blink¶

First I wanted to try out my debugger and programmer for the ATTiny412 I build in Electronic Production and just use this small and cute little board to test a simple LED Blink code without the Arduino library.

IMAGE_SMALL_ATTINY

I used the FTDI Programmer and first the SPDI adapter but it didn’t work with the board because the pins are wrongly connected I guess,

IMAGE_FTDI_UPDI_SETUP

After that, I used this one which then worked with following setup.

IMAGE_FTDI_UPDI_SETUP

10.3.1.1. AVR-GCC¶

Then I compiled this small program blink.c:

#define F_CPU 20000000ULL
#include <avr/io.h>
#include <util/delay.h>

#define PIN PIN4_bp
#define PERIOD 1000

int main(void) {
          PORTA.DIR = PIN;    // Choose pin 4 data direction
      while(1){
            PORTA.OUTSET = PIN; // set pin 4 as output pin
            _delay_ms(500);
            PORTA.OUTTGL = PIN; // Toggle state of pin 4 
            _delay_ms(200);
      }
}

with following commands just with avr-gcc and avr-libc:

GCC_ARGS=(-mmcu=attiny412 -O2);
avr-gcc "${GCC_ARGS[@]}" -c blink.c -o blink.o;
avr-gcc "${GCC_ARGS[@]}" blink.o -o blink.elf;
avr-objcopy -O ihex blink.elf blink.hex

and then with my flasher-setup, I installed pymcuprog with pip and then just used:

pymcuprog  -d attiny412 -t uart -u /dev/ttyACM0 ping                    # just for checking, if the connection works
pymcuprog -d attiny412 -t uart -u /dev/ttyACM0 write -f blink.hex       # for flashing the hex file

but this didn’t work :[, I need to look into that a bit more…

10.3.1.2. Arduino IDE¶

Then just as a Sanity check, I used the Arduino IDE, installed the tinyMegaCore boards and set the ATTiny412 as a target and the /dev/ttyACM0 as programmer. Then I just loaded the blink program, and flashed it to the board

IMAGE_ARDUINO_IDE

which worked :D.

IMAGE_FTDI_TINY_BLINK

10.3.2. Final Project POC¶

Now I used my proof of concept device from the last weeks to control the LED-Matrix with my touchpads, therefore I used the example-code for the Qtouch pins of the esp-idf. Unfortunately I did not choose the Charlieplexing for my matrix control because when I designed it, I didn’t know about such a thing.

IMAGE_BOARD

I only changed the callback for the threading-abstraction to check for the pad pressed and then blink one LED in the Matrix and some pragma-stuff.

/*
 * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: CC0-1.0
 */

#include "driver/gpio.h"
#include "driver/touch_pad.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include <inttypes.h>
#include <stdio.h>

#define TOUCH_BUTTON_NUM 3
#define TOUCH_CHANGE_CONFIG 0

#define LED_V0 1
#define LED_V1 2
#define LED_V2 3

#define LED_G0 6
#define LED_G1 5
#define LED_G2 4
static const char *TAG = "touch read";
static const touch_pad_t button[TOUCH_BUTTON_NUM] = {
    /*TOUCH_PAD_NUM1,*/
    /*TOUCH_PAD_NUM2,*/
    /*TOUCH_PAD_NUM3,*/
    /*TOUCH_PAD_NUM4,*/
    /*TOUCH_PAD_NUM5,*/
    /*TOUCH_PAD_NUM6,*/
    TOUCH_PAD_NUM7, TOUCH_PAD_NUM8, TOUCH_PAD_NUM9,
    /*TOUCH_PAD_NUM10,*/
    /*TOUCH_PAD_NUM11,*/
    /*TOUCH_PAD_NUM12,*/
    /*TOUCH_PAD_NUM13,*/
    /*TOUCH_PAD_NUM14*/
};

/*
  Read values sensed at all available touch pads.
 Print out values in a loop on a serial monitor.
 */

//
// MY CHANGES
//
static void tp_example_read_task(void *pvParameter) {
  uint32_t touch_value;

  /* Wait touch sensor init done */
  vTaskDelay(100 / portTICK_PERIOD_MS);
  printf(
      "Touch Sensor read, the output format is: \nTouchpad num:[raw data]\n\n");

  while (1) {
    for (int i = 0; i < TOUCH_BUTTON_NUM; i++) {
      touch_pad_read_raw_data(button[i], &touch_value); // read raw data.
      printf("T%d: [%4" PRIu32 "] ", button[i], touch_value);
      if (i == 0) {
        if (touch_value > 30000) {
          gpio_set_level(LED_V1, 1);
        } else {
          gpio_set_level(LED_V1, 0);
        }
      }
      if (i == 1) {
        if (touch_value > 30000) {
          gpio_set_level(LED_V2, 1);
        } else {
          gpio_set_level(LED_V2, 0);
        }
      }
      if (i == 2) {
        if (touch_value > 30000) {
          gpio_set_level(LED_V0, 1);
        } else {
          gpio_set_level(LED_V0, 0);
        }
      }
    }
    printf("\n");
    vTaskDelay(200 / portTICK_PERIOD_MS);
  }
}

//
// END MY CHANGES
//

void app_main(void) {
  /* Initialize touch pad peripheral. */
  touch_pad_init();
  for (int i = 0; i < TOUCH_BUTTON_NUM; i++) {
    touch_pad_config(button[i]);
  }
  gpio_reset_pin(LED_V0);
  gpio_reset_pin(LED_V1);
  gpio_reset_pin(LED_V2);
  gpio_reset_pin(LED_G0);
  gpio_reset_pin(LED_G1);
  gpio_reset_pin(LED_G2);
  /* Set the GPIO as a push/pull output */
  gpio_set_direction(LED_V0, GPIO_MODE_OUTPUT);
  gpio_set_direction(LED_V1, GPIO_MODE_OUTPUT);
  gpio_set_direction(LED_V2, GPIO_MODE_OUTPUT);
  gpio_set_direction(LED_G0, GPIO_MODE_OUTPUT);
  gpio_set_direction(LED_G1, GPIO_MODE_OUTPUT);
  gpio_set_direction(LED_G2, GPIO_MODE_OUTPUT);
  gpio_set_level(LED_G0, 0);
  gpio_set_level(LED_G1, 1);
  gpio_set_level(LED_G2, 1);
#if TOUCH_CHANGE_CONFIG
  /* If you want change the touch sensor default setting, please write
   * here(after initialize). There are examples: */
  touch_pad_set_measurement_interval(TOUCH_PAD_SLEEP_CYCLE_DEFAULT);
  touch_pad_set_charge_discharge_times(TOUCH_PAD_MEASURE_CYCLE_DEFAULT);
  touch_pad_set_voltage(TOUCH_PAD_HIGH_VOLTAGE_THRESHOLD,
                        TOUCH_PAD_LOW_VOLTAGE_THRESHOLD,
                        TOUCH_PAD_ATTEN_VOLTAGE_THRESHOLD);
  touch_pad_set_idle_channel_connect(TOUCH_PAD_IDLE_CH_CONNECT_DEFAULT);
  for (int i = 0; i < TOUCH_BUTTON_NUM; i++) {
    touch_pad_set_cnt_mode(button[i], TOUCH_PAD_SLOPE_DEFAULT,
                           TOUCH_PAD_TIE_OPT_DEFAULT);
  }
#endif
  /* Denoise setting at TouchSensor 0. */
  touch_pad_denoise_t denoise = {
      /* The bits to be cancelled are determined according to the noise level.
       */
      .grade = TOUCH_PAD_DENOISE_BIT4,
      .cap_level = TOUCH_PAD_DENOISE_CAP_L4,
  };
  touch_pad_denoise_set_config(&denoise);
  touch_pad_denoise_enable();
  ESP_LOGI(TAG, "Denoise function init");

  /* Enable touch sensor clock. Work mode is "timer trigger". */
  touch_pad_set_fsm_mode(TOUCH_FSM_MODE_TIMER);
  touch_pad_fsm_start();

  /* Start task to read values by pads. */
  xTaskCreate(&tp_example_read_task, "touch_pad_read_task", 4096, NULL, 5,
              NULL);
}

There I first mixed the pin-direction up in my schematics, where I then tested the LEDs manual:

IMAGE_TEST_LEDs

But then I corrected the code and it worked :D

10.3.3. Pomodoro Timer¶

10.4. Notes¶

https://learn.adafruit.com/adafruit-neopixel-uberguide/best-practices
https://cdn-shop.adafruit.com/datasheets/WS2812B.pdf
https://gcc.gnu.org/wiki/avr-gcc