Compute module for Arduino
https://redd.it/1pww5y2
@r_embedded

SD Card module not responding over SPI on ESP32 - Need Help

Hi everyone,

I’m trying to use an SD card module with my ESP32 over SPI, but I keep getting errors when mounting the filesystem. My setup:

ESP32 pins:

MISO → 19

MOSI → 23

SCK → 18

CS → 15

3.3 V → VCC

GND → GND

The SD card module is a cheap one I got from China. There are 10 KΩ resistors in series on MISO, MOSI, CS, and SCK on the module.

SD card: 16 GB, FAT32

Here’s the code I’m using:

#include <stdio.h>
#include "espsystem.h"
#include "esplog.h"
#include "esperr.h"

#include "driver/spicommon.h"
#include "driver/spimaster.h"

#include "sdmmccmd.h"
#include "espvfsfat.h"

#define PINNUMMISO 19
#define PINNUMMOSI 23
#define PINNUMCLK 18
#define PINNUMCS 15

static const char TAG = "SD_CARD";

void app_main(void)
{
esp_err_t ret;

// Use SPI host
sdmmc_host_t host = SDSPI_HOST_DEFAULT();
host.slot = SPI2_HOST; // HSPI
host.max_freq_khz = 100; // start super slow

// SPI bus configuration
spi_bus_config_t bus_cfg = {
.mosi_io_num = PIN_NUM_MOSI,
.miso_io_num = PIN_NUM_MISO,
.sclk_io_num = PIN_NUM_CLK,
.quadwp_io_num = -1,
.quadhd_io_num = -1,
.max_transfer_sz = 8192,
};

ret = spi_bus_initialize(host.slot, &bus_cfg, SPI_DMA_CH_AUTO);
if (ret != ESP_OK) {
ESP_LOGE(TAG, "Failed to initialize SPI bus");
return;
}

// SD SPI device configuration
sdspi_device_config_t slot_config = SDSPI_DEVICE_CONFIG_DEFAULT();
slot_config.gpio_cs = PIN_NUM_CS;
slot_config.host_id = host.slot;

// FAT filesystem mount configuration
esp_vfs_fat_sdmmc_mount_config_t mount_config = {
.format_if_mount_failed = false,
.max_files = 5,
.allocation_unit_size = 4096
};

sdmmc_card_t card;

ESPLOGI(TAG, "Mounting SD card at 100 kHz...");
ret = espvfsfatsdspimount("/sdcard", &host, &slotconfig, &mountconfig, &card);

if (ret != ESPOK) {
ESPLOGE(TAG, "Failed to mount filesystem (%s)", esperrtoname(ret));
return;
}

ESPLOGI(TAG, "SD card mounted successfully!");
sdmmccardprintinfo(stdout, card);

ESPLOGI(TAG, "You can now increase host.maxfreqkhz gradually (e.g., 8MHz, 16MHz, 20MHz) and test again.");
}





And here’s the log I get:

rst:0x1 (POWERONRESET),boot:0x13 (SPIFASTFLASHBOOT)
...
I (330) SDCARD: Mounting SD card at 100 kHz...
I (330) sdspitransaction: cmd=52, R1 response: command not supported
I (370) sdspitransaction: cmd=5, R1 response: command not supported
E (3370) sdmmccommon: sdmmcinitocr: sendopcond (1) returned 0x107
E (3370) vfsfatsdmmc: sdmmccardinit failed (0x107)
E (3370) SDCARD: Failed to mount filesystem (ESPERRTIMEOUT)


I’ve tried powering the module with 3.3 V and verified the wiring. The SD card is inserted and Formated to FAT32.

https://redd.it/1pww1uk
@r_embedded

i want make one like this i need help this is mini camera Supports sd card i want know what prices i need to do one like this I see them being sold a lot on websites, but I want to make them myself.
https://redd.it/1pwta5q
@r_embedded

Learn Embedded Systems With Hands-On Tinkering Lab

If anyone here wants to seriously get into Embedded Systems, UNLOX just launched a beginner-friendly program that takes you from basics to advanced — and the best part is the Tinkering Lab access. You actually get to work with real microcontrollers, sensors, protocols, and hardware instead of only watching tutorials.

The course covers Embedded C, STM32/ESP32, UART/SPI/I2C, RTOS basics, debugging, firmware, and real project building. It’s super practical and perfect for students who want hands-on learning plus guidance. DM me for more guidance



https://redd.it/1pwzl52
@r_embedded

How do you program an interface for a memory?

Hi noob here I'm trying to make a simple interface for an old parallel sram and I really don't get on how I should time the signal for the Write enable pin with the data pins and the address pins.i put on write enable before the rest of the pins a cycle of clock later losing time I feel like I am missing something

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qron0b: a sleek & low-power binary wristwatch
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ESP32 beginner what should I buy to get started?

Hey everyone,

I want to get started with the ESP32 and embedded programming, but I’m a bit unsure what hardware is actually worth buying at the beginning.

What kind of basic accessories would you recommend right away? (breadboard, sensors, etc.)

I’d like to start with simple projects first and then slowly work my way up.

I’d appreciate hearing about your experiences thanks! 🙌

https://redd.it/1px5ttr
@r_embedded

Clean architecture in rtos

I'm working on a RTOS robot and I've some doubts on the best architecture. I initially use the clean architecture pattern like this:

>firmware/
├── src/
│ ├── domain/ # Entités et règles métier
│ │ ├── entities/ # Ex: RobotState
│ │ ├── repositories/ # Interfaces (ex: RobotRepository)
│ │ └── usecases/ # Cas d'utilisation (ex: SafetyUseCase)
│ ├── application/ # Logique applicative et tâches RTOS
│ │ ├── tasks/ # Tâches RTOS (ex: SafetyTask, SensorTask)
│ │ ├── services/ # Services applicatifs
│ │ └── dto/ # Data Transfer Objects
│ ├── infrastructure/ # Implémentations concrètes
│ │ ├── drivers/ # Pilotes matériels (ex: ADC, CAN)
│ │ ├── protocols/ # Protocoles temps réel (ex: CANopen)
│ │ ├── communication/ # Communication inter-tâches (queues RTOS)
│ │ └── shared_resources/ # Ressources partagées (queues, sémaphores)
│ └── interfaces/ # Interfaces pour le middleware
│ ├── grpc/ # Service gRPC léger
│ └── ros2/ # Bridge ROS 2 (optionnel)
├── include/ # Fichiers d'en-tête communs
├── config/ # Configuration RTOS (ex: FreeRTOSConfig.h)
└── tests/ # Tests spécifiques RTOS
├── unit/ # Tests unitaires
├── integration/ # Tests d'intégration
└── fuzz/ firmware/
├── src/
│ ├── domain/ # Entités et règles métier
│ │ ├── entities/ # Ex: RobotState
│ │ ├── repositories/ # Interfaces (ex: RobotRepository)
│ │ └── usecases/ # Cas d'utilisation (ex: SafetyUseCase)
│ ├── application/ # Logique applicative et tâches RTOS
│ │ ├── tasks/ # Tâches RTOS (ex: SafetyTask, SensorTask)
│ │ ├── services/ # Services applicatifs
│ │ └── dto/ # Data Transfer Objects
│ ├── infrastructure/ # Implémentations concrètes
│ │ ├── drivers/ # Pilotes matériels (ex: ADC, CAN)
│ │ ├── protocols/ # Protocoles temps réel (ex: CANopen)
│ │ ├── communication/ # Communication inter-tâches (queues RTOS)
│ │ └── shared_resources/ # Ressources partagées (queues, sémaphores)
│ └── interfaces/ # Interfaces pour le middleware
│ ├── grpc/ # Service gRPC léger
│ └── ros2/ # Bridge ROS 2 (optionnel)
├── include/ # Fichiers d'en-tête communs
├── config/ # Configuration RTOS (ex: FreeRTOSConfig.h)
└── tests/ # Tests spécifiques RTOS
├── unit/ # Tests unitaires
├── integration/ # Tests d'intégration
└── fuzz/


But I'm not sure it's the best architecture.

Any thoughts ?

https://redd.it/1px72xf
@r_embedded

Advice for writing lib for modules

Hi so im starting to write library for modules is there any suggestion for me im so confused with the doc i just now that i show read protocol page and register page



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@r_embedded

My first bulk usb data stream on pico 2 using tinyusb
https://embeddedjourneys.com/blog/first-time-usb-data-stream-on-pico/

https://redd.it/1px9g4z
@r_embedded

STM32L432KC CubeMX configuration

Hi all,

I’m fairly new to STM32 and would like to design and manufacture a custom board to play & test with both software & hardware functionality. I started by configuring the MCU in CubeMX.

I don’t have a specific application, but I’d like to start with a relatively simple, low pinout STM32 chip and be able to test most of its features (ADC, DAC, I2C, etc.).

Could you please review the pinout and let me know if anything needs to be changed or if something is missing?

All the free pins (except Power,BOOT,NRESET) will be used as GPIOs (LED, button etc..)

https://preview.redd.it/vgfnejflmt9g1.png?width=846&format=png&auto=webp&s=277c59ee6d0e62181cd176579ee03e8ce09d3fb0




Thank you.

https://redd.it/1pxa70u
@r_embedded

ESP32 Servo Control with Level Shifter and Breadboard Power Supply
https://redd.it/1pxhd9f
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Tiny Robot Gadget for Desk Rohee
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@r_embedded

Need assistance

Hi I had been working on uart to bt bridge, what I am facing is that I had configure uart rx as interrupt I had getting a large chunks of data from the another device, what I had facing is that I am not getting whatever data I had received through rx .

below is my code

uint16 head = 0;

uint16 tail = 0;

volatile bool uart_rx_flg = 0;

//this is my uart config for interrupt

uartrxirqtriglevel(UART1, 1);

uartsetirqmask(UART1, UARTRXIRQMASK );

plicsetpriority(IRQ18UART1, IRQPRILEV3);

\attribute_ram_code_sec_

void uart1_irq_handler(void) {

while (uart_get_rxfifo_num(UART1) > 0) {

if( ( (head + 1) % AT_CMD_BUFFER ) != tail ) // Check for buffer overflow

{

at_cmd_buffer[head\] = uart_read_byte(UART1);

head = (head + 1) % AT_CMD_BUFFER;

}

}

uart_rx_flg = 1;

/*UART_RXBUF_IRQ_STATUS:When the number of rxfifo reaches the set threshold(uart_rx_irq_trig_level), an interrupt is generated, and the interrupt flag is automatically cleared; stated in docs*/

}

}
in main loop calling

void serial_rx_handler(void) {

if(!uartrxflg)return;

else

{

uint08 tmp_buffer[TMP_BUFFER_SIZE\];

uint16 len = 0;

while (tail != head && len < TMP_BUFFER_SIZE) {

tmp_buffer[len++\] = at_cmd_buffer[tail\];

tail = (tail + 1) % AT_CMD_BUFFER;

}

if(len > 0)

{

if (app_spp_handle > 0 )

{

btp_spp_sendData(app_spp_handle, nullptr, 0, tmp_buffer, len);

}

else if (g_connHandle != 0/* && idx > 0*/)

{

blc_gatt_pushHandleValueNotify(g_connHandle, SPP_SERVER_TO_CLIENT_DP_H, (void * ) tmp_buffer, len);

}

else

{

//for the parsing of at cmds

}

}

if(tail == head)uart_rx_flg = 0;

last_rx_tick = 0;

}

}let me know where I am getting wrong ,

Thx

https://redd.it/1pxnc07
@r_embedded

Planning the long game: A roadmap into Embedded Robotics for grad school and beyond?

I'm a second-year student majoring in Robotics/Mechatronics Engineering at a top tech university in Vietnam. Right now, my program is pretty heavy on the mechanical side, but I really want to get deeper into electronics and computer science. Down the line, I'm thinking about a Master's in Electrical Engineering (EE) or Mechatronics & IT, focusing on using AI in robotics and automation.

While looking into different paths, I got really interested in embedded systems and IoT for robotics. It seems like a great fit because it mixes hardware and software, and you still need to understand the mechanical side to make things work properly. I'd love to learn more and build a career in this direction.

The thing is, my uni only has a couple of basic electrical courses (mostly about components and equipment). There aren't many options to dive deeper into electronics or embedded programming here, so I'd really appreciate some advice from people in the field.

Could you give me some guidance on:

* What fundamental topics should I focus on learning on my own? (e.g., microcontrollers, digital/analog circuits, communication protocols, maybe RTOS?)
* What programming languages and tools are must-knows? (I've heard C/C++ is key, but what about Python, Linux, or PCB design tools?)
* Any good starter projects or resources to help me build a hands-on portfolio?

Also, it would be awesome if you could suggest some universities known for their strong programs in this area. I'm hoping to plan ahead, with the goal of pursuing a combined Master's/PhD while working on side projects before jumping into the industry.

Any tips, personal experiences, or resource recommendations would be a huge help. Thanks so much!


https://redd.it/1pxo2ru
@r_embedded

Legality and Code Libraries?

I'm working on an STM32 project. I've also been trying to stay away from Arduino hardware and software for learning purposes, and due to the recent Qualcomm take over

Right now the project needs a small LCD display to display some text. I've seen a lot of info saying to use a pre-built library from GitHub. Problem is it's converted from an Arduino based library...

I'm confused on if I can use this code and what limitations there could be? Would changes in the Arduino TOS affect a library converted from their own, and an old GPL license, last updated 7 years ago? (The code in question) https://github.com/SayidHosseini/STM32LiquidCrystal

Legally, what should I worry about or consider here?

https://redd.it/1pxwb1d
@r_embedded

Sensor not working when ethernet is connected in STM32

Hey peeps, I am a fresher who got placed as an embedded engineer. I did my bachelors in Computer Science Engineering. So I am new to the embedded world. As a part of my training I and a friend is working in a project where we seem to be stuck because of ethernet/RJ45.
The project is about using a gesture sensor to detect gestures and map it to a certain action. So whenever that gesture is performed associated action will take place.
The issue: We were able to detect gestures and print what gesture was being detected, but to move forward we needed to use ethernet/LWIP. So in normal case, when I hold 1 finger it prints "count 1" and when its 2 fingers it prints "count 2" and so on. We keep polling to see if there is gesture and so as long as we show the gesture the output keeps getting printed. Now if we connect the ethernet cable to the board this stops working, like the output sometimes only prints the gesture that we are showing otherwise it prints the default value(which is shown when no gesture is detected).

Board I am using: STM32 nucleo F207ZG
Sensor l am using: Grove Smart IR Gesture Sensor V1.1 PAJ7660 (https://wiki.seeedstudio.com/grove_gesture_paj7660/)
Output is being shown in PUTTY.
Link to github: https://github.com/txr-academy/GestLink

https://redd.it/1pxxrtr
@r_embedded

I built a developer kit for my recent AFR (air to fuel ratio) gauge project

https://preview.redd.it/9yv8mheorz9g1.jpg?width=1536&format=pjpg&auto=webp&s=768fcf32a2f58e8d621e3abad4bd07f4d603c9d2

Actually this is my first complex project where ım using a LCD its a 2 inch tft display with a ILI9225 driver and ım using the 16 bit mode to drive it and ı added some buttons buzzer and a pot for a adc simulation

https://redd.it/1pxz813
@r_embedded

Are breakout boards used in commercial/industrial products?

Are breakout boards used in commercial/industrial products?

Hello everyone. I had this simple question.

BME280 is a very small sensor itself and most often it comes with it's own breakout board.

I was wondering if people in industry use these breakout boards as they are? As soldering bme280 itself, the tiny silver cube, imo seems a difficult task.

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@r_embedded

Where can I learn the business aspect of embedded systems?

I'm jobless but I think I know many things in embedded software.

Companies are rejecting me. Feeling like I have reached a dead end.

Which study could give me the knowledge by which I could understand business aspect of embedded systems?

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@r_embedded

Stm32L476RG

Hello all , does anyone have any .c and .h files for the liquid lcd display? Im on bare metal c right now ive done code myself but i just get blocks and not full text.

https://redd.it/1py8rn2
@r_embedded