DevHeads IoT Integration Server

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DevHeads IoT Integration Server

The DevHeads IoT Integration Server accelerates technology engineering by helping pro devs learn, share and collaborate.

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Abdelrahman Ibrahim
Abdelrahman Ibrahim
View on Discord
12/18/2024

Choosing Between Interrupts and Polling for Critical Applications Like Airbags in Static Real-Time S

Hi.. critical applications like airbag it's better to use interrupt or polling with it in static real-time system...
RAJASEKAR L
RAJASEKAR L
View on Discord
12/18/2024

Hi...I am trying to flash image on sd card but I failed . Board is STM32Mp135

Hi...I am trying to flash image on sd card but I failed . Board is STM32Mp135
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Sterling
Sterling
View on Discord
12/18/2024

Garbled Characters in HAL_UART_Transmit_IT on STM32 F303RE Causes and Solutions

I’m using HAL_UART_Transmit_IT in two places with the Nucleo F303RE board. In HAL_UART_RxCpltCallback, I use it to echo received UART data, and it works fine. In Print_CAN_Frame, I send messages every 3 seconds. Previously, I used HAL_UART_Transmit, which worked, but after switching to HAL_UART_Transmit_IT, I get garbled characters in TeraTerm. Both functions use the same UART configuration: BaudRate 115200, WordLength 8B, StopBits 1, Parity None, TX/RX Mode. The issue appears only with interrupt-driven transmission. What could be causing this behavior, considering both functions take identical arguments, and how should I handle potential buffer or timing issues? Here is my code file;...
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Mohan
Mohan
View on Discord
12/17/2024

How to solve this error?

@Marvee Amasi how to solve this error
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te0
te0
View on Discord
12/17/2024

LVGL Memory Allocation Issues on ESP32 with esp_lcd

anyone worked with LVGL in ESP IDF?
Marvee Amasi
Marvee Amasi
View on Discord
12/17/2024

Why Does movl (%eax), %edx Crash After Using Custom malloc_ Implementation in Assembly?

I have implemented a custom memory allocation function using sys_mmap for memory allocation. Here’s my code for the malloc_ function: ``` malloc_: pushq %rbp...
Mohan
Mohan
View on Discord
12/17/2024

Have anyone worked with nucleo board lwip to send data to aws iot core

Have anyone worked with nucleo board lwip to send data to aws iot core
Marvee Amasi
Marvee Amasi
View on Discord
12/17/2024

How to Preserve 64-bit Register Values When Using movl in x86_64 ROP Constraints

In x86 64 machine code, when the movl instruction is used with a register destination, it zeroes the higher order bytes of the 64 bit register. How can I use movl while preserving the original value of the full 64-bit register? For example, if I 
movq %rsp, %rax
movq %rsp, %rax
and then call 
movl %eax, %edx
movl %eax, %edx
is there a way to use movl or perform some other operations after movl so that %rdx retains the original value of %rsp? I cant use movq bcus in my current situation *a ROP attack, only movl instructions are available in my gadget farm actually. I also have access to andb, orb, cmpb, and testb instructions...
te0
te0
View on Discord
12/17/2024

have you used a higher baud rate for ESP32s?

have you used a higher baud rate for ESP32s?
Marvee Amasi
Marvee Amasi
View on Discord
12/17/2024

How can I change VEX instructions between 16, 32, and 64-bit modes?

Does anyone understand how to work with MASKMOVDQU, cus I'm stuck by it's instruction from the page 902 of the Intel x64 manual . I am confused on how to adjust the register sizes for this instruction. Here the documentation mentions that the default memory location is DS:DI/EDI/RDI, but the opcode includes 0x66 How should I handle this 0x66? Should I replace it with 0x67 or use the REX.W prefix for EDI/RDI registers to adjust for the different sizes? So there is a VEX version of this instruction listed as:...
melta101
melta101
View on Discord
12/16/2024

What IDE setup do you use for remote debugging with GDB/KGDB and OpenOCD?

Hello @MCU, MPU & Firmware ! If you use GDB or KGDB, what is your IDE setup while debugging remote device with a openocd running on it?...
Daniel kalu
Daniel kalu
View on Discord
12/16/2024

Can connecting a 5V device without level shifting cause these errors?

I'm integrating industrial sensors with AWS IoT Core using ESP32, configuring MQTT communication to send sensor data to the cloud. The 5V TTL serial device is a temperature sensor using RS232 protocol. When connecting it directly to the ESP32's 3.3V UART pins, I notice occasional garbage values in received data through serial monitoring tools. This caused incorrect sensor readings to be sent to the cloud, resulting in inaccurate IoT analytics. To troubleshoot, I've observed the garbage values using a serial terminal and scope measurements. I haven't tried reducing the baud rate yet, but I have verified the issue persists across multiple cloud connections. Can connecting a 5V device without level shifting cause these errors?...
te0
te0
View on Discord
12/16/2024

any method of increasing the rendering speed of a display with the esp_lcd component?

any method of increasing the rendering speed of a display with the esp_lcd component?
Dtynin
Dtynin
View on Discord
12/16/2024

Fixing CAN Bus Overload Issues in Multi-Node Sensor Systems Using AVR128DA48 and MCP2515

Hey guys, I previously worked on an automated irrigation system where different sensors (moisture, temperature) spread across large farmland communicate with a central controller over the CAN Bus. Each sensor node is equipped with an AVR128DA48 microcontroller and an MCP2515 CAN controller to relay data about soil conditions to the controller for real-time decision-making. I’ve set up the CAN Bus network and successfully initialized the CAN controller on each sensor node. The sensor data is being collected properly, and I've verified that the SPI communication between the AVR128DA48 and the MCP2515 is working correctly. However, I’m running into an issue when attempting to synchronize the sensor data broadcasts. The issue occurs during message reception on the central controller. While I’m able to send data from individual sensors, the central node fails to synchronize the data streams. The can_recv() function sometimes receives data, but other times it throws an -EBUSY (Bus Busy) error, suggesting the bus is overloaded or not handling multiple messages well....
Renuel Roberts
Renuel Roberts
View on Discord
12/16/2024

How to Ensure Reliable Data and Predictions for Skin Cancer Detection Using ESP32 and TCS3200?

Am working on an AI-powered health monitoring system using an ESP32 and a TCS3200 Color Sensor to analyze skin pigmentation and detect potential cancerous cells by identifying irregularities in skin color. The sensor initializes correctly, but I am encountering inconsistent data, leading to incorrect predictions about potential skin cancer. my aim is to: - Use machine learning to analyze color data and predict the presence of cancerous cells based on irregular pigmentation....
Daniel kalu
Daniel kalu
View on Discord
12/16/2024

What Causes 'Clock Stretch Too Long' Errors When Flashing ESP32?

Hey guys I'm experiencing intermittent timeouts and invalid packet errors while programming my ESP32-WROOM-32 module via USB using esptool version 2.8 and ESP-IDF version 4.4 for a cloud-connected IoT project integrating with AWS IoT Core. I've been trying to flash custom firmware, but the process consistently fails. Upon reviewing the error logs, I noticed the error message "timeout: clock stretch too long" followed by "invalid packet" errors. I've verified that the board is in boot mode by pul...
Marvee Amasi
Marvee Amasi
View on Discord
12/16/2024

What Are the Architectural Constraints in Haswell That Limit CPE Optimization?

I want to understand why any scalar version of the inner product procedure cannot achieve a CPE less than 1.00 on an Intel Core i7 4790 Haswell processor, Ubuntu 20.04 Linux Kernel 5.4, with GCC 9.3.0 compiler. I want to optimize the inner product procedure using 6x1a loop unrolling on the Intel Core i7 Haswell processor. For integer data, my unrolled version gives a CPE as in cycles per element of 1.07. For floating-point data, it still remains at 3.01. I understand that pipelining and vectorization offer opportunities for parallelism, but is there a fundamental limitation in scalar code that prevents CPE from dropping below 1.00, even with loop unrolling?...
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Sterling
Sterling
View on Discord
10/18/2024

Issues with I2C Communication to VL53L0X Sensor Using STM32F103C8 Without ST Library

I am using the VL53L0X sensor with an STM32F103C8 microcontroller and want to communicate with the sensor directly over I2C without using ST's library. My goal is to minimize project size and better understand the low-level protocol. I’ve initialized the I2C interface using CMSIS and am sending commands like setting the control register and reading measurement data, but I’m getting inconsistent responses. See how I initialized the i2c: ...
Dtynin
Dtynin
View on Discord
10/18/2024

Issue with Command Handling in AVR128DA48 UART Communication

I am using AVR128DA48 microcontroller to control an LED in serial communication. The way I set it up is not complex; I’m sending ‘ON’ and ‘OFF’ commands from a python script over UART to toggle the LED on the microcontroller. Funny how I am encountering an issue where the first command is ignored, but the second one triggers a response. Here’s what happens: - I send ‘ON’ – the microcontroller does not respond....
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Camila_99$$
Camila_99$$
View on Discord
10/18/2024

Optimizing Speed and Acceleration for Nema34 Motor Control with DM680E Driver

Hi 👋🏻 My friend and I wrote this code to control a Nema34 motor with a DM680E driver for a drilling cycle. We want to dynamically adjust the speed between fast movement (for chip removal and advancing) and slow movement (for drilling into the material), while maintaining smooth acceleration transitions between these speeds. We’ve mentioned needing two speed parameters—fast and slow—but we’re unsure about the exact values that would be optimal for this application. If anyone has advice on how to calculate or determine the best speed and acceleration values for this setup, it would be greatly appreciated. ...
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