a bit of esp32-s3 c++ code

I recently purchased an inexpensive ESP32-S3-DevKitC-1-N32R8 development board. That’s an ESP32-S3 board with an ESP32-S3-WROOM-2, 32MB of FLASH and 8MB of SPIRAM. In one particular experiment I wanted to work with the ESP-IDF libraries for accessing the FLASH and SPIRAM. So far those attempts have failed in spite of trying to follow the demo code provided in the ESP-IDF. I’m currently using version 4.4.2 of ESP-IDF.

What I have done is create a project that allows me to get something running, then add features to a working project. This is the baseline project I’ve created, yet another RGB LED flasher. This one is written in C++ and uses C++ tuples to create a collection (vector) of colors to display on the RGB LED. I wanted something similar to what I do in MicroPython, where I create a Python collection and simply iterate over the collection of colors (see line 44). In the past when trying something similar in standard C I always had to know the size of my array/vector. With C++14, I can simply define my vector of colors, and then use the C++’s for-each construct to iterate over the vector of color tuples.

Finally, I should note that the RGB LED is on GPIO38. I used idf.py menuconfig to set the GPIO pen.

/* ESP32-S3 N32R8 Work Example

   This example code is released under the Apache License, Version 2

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#include <vector>
#include <tuple>

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "led_strip.h"
#include "sdkconfig.h"

static const char *TAG = "ESP32-S3-N32R8 Work Example";

/* Use project configuration menu (idf.py menuconfig) to choose the GPIO
   to blink, or you can edit the following line and set a number here.
*/
static const uint8_t BLINK_GPIO = CONFIG_BLINK_GPIO;

static led_strip_t *pStrip_a;

/* Create a vector of color tuples to cycle through continuously.
   I wanted something simple and similar to what I do in Python.
   I don't believe this is it (the simple part).
 */
typedef std::tuple<int, int, int, int> led_color;
static const std::vector <led_color> colors {
    {0,32,0,0},  // red
    {0,0,32,0},  // green
    {0,0,0,32},  // blue
    {0,0,32,32}, // cyan
    {0,32,0,32}, // magenta
    {0,32,16,0}, // yellow
    {0,0,0,0}    // black
    };

static void cycle_rgb_led_colors(void) {
    for(auto c : colors) {
        pStrip_a->set_pixel(pStrip_a,
            std::get<0>(c), std::get<1>(c), std::get<2>(c), std::get<3>(c));
        pStrip_a->refresh(pStrip_a, 100);
        vTaskDelay(900 / portTICK_PERIOD_MS);
        
        // Turn RGB LED off by clearing all its individual LEDs.
        //
        pStrip_a->clear(pStrip_a, 50);
        vTaskDelay(100 / portTICK_PERIOD_MS);
    }
}

static void configure_rgb_led(void) {
    // LED strip initialization with the GPIO and pixels number.
    pStrip_a = led_strip_init(CONFIG_BLINK_LED_RMT_CHANNEL, BLINK_GPIO, 1);
    // Clear all LEDs in RGB LED to turn it off.
    pStrip_a->clear(pStrip_a, 50);
}

extern "C" void app_main(void) {
    configure_rgb_led();

    ESP_LOGI(TAG, "Cycle RGB LED Colours.");

    while (true) {
        cycle_rgb_led_colors();
    }
}

audio problem with vivaldi on linux mint

Example tab showing muted audio

In an earlier post ( https://arcanesciencelab.wordpress.com/2022/08/03/linux-mint-21-report/ ) I wrote that I couldn’t hear audio when playing back streaming video within Vivaldi on Linux Mint 21. Today, while doing some research on another issue, I decided to check up on Trump’s Troubles via CNN. Without thinking I clicked the play button and once again didn’t hear the audio. That’s when I spied the muted speaker icon on the tab. A little discovery by right clicking on the tab showed a “Mute Tab” menu entry. It was enabled. When I clicked on the menu entry and cleared the check, audio started to play.

But here’s the thing. If I close the tab and open a new one, go back to CNN, play the same clip, then right-click to get the tab menu, Mute Tab isn’t set. If I set it then unset it, audio again starts to play. So it would seem we have a bug on Linux Mint with the latest version of Vivaldi (v 5.4.2753.28). I guess the next step is to file a bug report. I’ll do it in the morning; right now it’s a Friday evening and I’m too tired to really care about filing that bug report.