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Cjosh.1
Associate II
February 25, 2021
Question

Why Nucleo F746ZG showing LD5 (Over current) on when running simple LED blink code? Also controller heating is more

  • February 25, 2021
  • 11 replies
  • 3218 views

Hello i am using Nucleo F746ZG board. When i run simple LED blink code with below code its not showing LD5 (Over current) on.

#include "mbed.h"
 
// Blinking rate in milliseconds
#define BLINKING_RATE 500ms
int main() {
 // Initialise the digital pin LED1 as an output
 DigitalOut led(LED1); // Green Color
 while (true) {
 led = !led;
 ThisThread::sleep_for(BLINKING_RATE);
 }
}

But when i changed code given below LD5(Over Current) blinking. and also controller heating is too much.

#include "mbed.h"
 
// Blinking rate in milliseconds
#define BLINKING_RATE 500ms
int main() {
 // Initialise the digital pin LED1 as an output
 DigitalOut led(LED1); // Green Color
 while (true) {
 led = !led;
 }
}

Reason behind checking this code is my main code was showing Over current LED ON, so i changed code to LED Blink, and found this issue. Looks like Nucleo board having issue for continuous operation. I have Connected SD card Module with SDMMC CN8 , when i remove SD card module from SDMMC its not showing over current.Can someone please help?

This topic has been closed for replies.

11 replies

KnarfB
Super User
February 25, 2021

No, Nucleo boards dot get overloaded by a blinky program. If you see the correct LED blinking, check the connection with " SD card Module with SDMMC CN8" (not sure what this is) or show the relevant schematics.

hth

KnarfB

Cjosh.1
Cjosh.1Author
Associate II
March 16, 2021

Hello @KnarfB​ Thanks for looking onto this thread.

Yes you are right. simple LED blink code with SD card interface with the board not creating this issue. I have asked detailed question with my schematic from which i am facing overcurrent and overheating issue. Please check this thread(https://community.st.com/s/question/0D53W00000e04i8SAA/nucleo-overcurrent-and-overheating-issue). Thank you

KnarfB
Super User
March 16, 2021

Yes, I have seen your new post. Nucleo power supply via VIN+GND is, in general, not a problem.

There are only 2 more pins connected, so you can find out what happens by doing some U/I measurements at those external connections.

Quick notes: the relay should not disconnect cartridge GND. When GND open, the cartridge VPH is still connected and this mighht do bad things via FIRE1.

The relay should perhaps be driven by a proper driver, including a freewheel diode, not a logic level converter.

Don't know the specs of the relay and the cartridge though, so I may be wrong.

hth

KnarfB

Cjosh.1
Cjosh.1Author
Associate II
March 16, 2021

Hy @KnarfB​ I can give specification details about relay and cartridge if it helps to identify my issue. below are the details

Relay: I am using relay similar to this(https://components101.com/switches/5v-single-channel-relay-module-pinout-features-applications-working-datasheet). And relay board already having freewheel diode. Image attached0693W000008x0TNQAY.png 

Cartridge: Cartridge typical supply voltage is 11v. Image attached0693W000008x0RgQAI.png 

KnarfB
Super User
March 17, 2021

Okay, the relay seems haveing its driver included. My other remarks still apply.

hth

KnarfB