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Motor driver not working properly

Noochee — Fri, 20 Feb 2026 22:50:49 +0000

I built an obstacle avoiding robotic car using Arduino, dc motors and a motor driver(L293D) , ultrasonic sensor and servo, i added LCD, a buzzer, an LED and a bluetooth module, but it's getting overloaded i guess and it doesn't work, what do i do?

Bluetooth Speaker won't turn on

servitec — Tue, 20 Jan 2026 07:00:52 +0000

I know is not probably the best place for a newbie, the AI somehow helps but I definitely prefer go with the experts. I am fascinated with the laws of electronic, but more than ever I know it demands a serious compromise to enter this amazing world.

Board Description: HXYT-A0-665-REV1.1 (A bluetooth speaker)
The speaker wont turn on, is doing nothing.
SIDE A
Compt.1= 56HS5, B310B (5 pins)
Compt.2= J6 (3 pins) ?
Compt.3 4004A, 33580KM
Side B
Compt.1= 4R7 (inductor)
Compt.2= SS54 (SCHOTTKY BARRIER RECTIFIER)
Compt.3= M8889, Y4D371 (8 Pins) ?
Compt.4 PNSA15E7E, X0B253, 2359

--When connected the battery in the terminals, it shows normal (aprox 5V)
--I tested the negative and positive spots in reverse of battery connector and off course no shorted
--When first tested pin C of power button, it shows 0.840V, after some tests is showing 2.4V when first push the power button it drops to 0V but now no more drops and it gets 2.4 V no matter if push the power button
--Tested all capacitors of Side A and all of them are ok, also the capacitor X which is connected to the Compt.3, the component 3 seems to be a DC-DC converter, the capacitor X is in parallel of pins 4 and 6. When checking the VIN in Compt.3 (pin5) is ok, but when I push the power button there is no VOUT (pin1)
--When connected to the charger, the device’s charging led turns on and the board battery terminals shows the charging voltage.

In Side B

We can see the battery port, the left pin is the + one, that pin goes to the compt.1 through pad named in the image as “pad positive pin”, then the compt.1 is connected to the compt.2 (I tested both and they seem to be ok). I tested all capacitors in Side B, all of them are ok except capacitor X. The capacitor X is connected to the pin that is marked with a yellow face sticker in compt.4, and I'd like to have the PCB's information or at least the compt.4's (or the M8889) in order to know that capacitor values.
What more testing do you recommend me to apply, what is component 2 in side A, what is component 4 in side B, is it a multiplexer? What is component 3 in side B, is it a switch IC? What recommendations can you give me when is hard to find a component by its code?

Side-A.jpg

How can I safely power a BLDC motor from a hard disk drive?

Anil_Tech — Tue, 28 Oct 2025 05:32:49 +0000

I have a brushless DC motor taken from an old hard disk drive and I want to power it safely for testing or small DIY applications. Since these motors are usually designed for specific control circuits, I’m not sure about the correct voltage, current, and driving method.

What’s the safest way to power and control a hard drive BLDC motor?

Should I use a dedicated ESC, a custom driver circuit, or a microcontroller-based solution?
Any tips for determining the correct pinout and avoiding damage to the motor would also be helpful.

How can servo jitter be reduced in Arduino projects?

Anil_Tech — Tue, 21 Oct 2025 06:24:54 +0000

I’m controlling a servo motor using an Arduino, but it occasionally jitters even when it’s supposed to hold a fixed position. The power supply seems stable, and the signal wire is properly connected. What are the common causes of servo jitter in Arduino projects, and what are the best methods to minimize or eliminate it?

Are there any hardware or software techniques—like adding capacitors, using separate power sources, or applying code-based filtering—that can help achieve smoother servo movement?

SPI vs I2C vs UART: which interface should I use for my application and why?

techy ishan — Fri, 10 Oct 2025 05:04:48 +0000

I need to pick one interface before finalizing my PCB and firmware. Short on‑board sensor links; priorities are minimal pins, low power, and reliable data. Which would you choose and why?

DMM in mA mode causes ~0.6 V drop — normal burden voltage? How can I minimize it?

JannikTechy — Thu, 09 Oct 2025 05:21:09 +0000

I’m measuring the current draw of a low-voltage load and noticed my handheld DMM, in mA mode, is dropping about 0.6 V across itself. Is that normal “burden voltage,” and what’s the best way to reduce it?

How do I choose the right op-amp for audio applications?

Roshan — Mon, 29 Sep 2025 05:28:54 +0000

When it comes to audio circuits, I’ve seen many people emphasize the importance of choosing the right op-amp, since it can significantly affect noise, distortion, and overall sound quality.

What factors should be considered when selecting an op-amp specifically for audio applications? For example, how important are parameters like slew rate, input noise, bandwidth, or THD+N (Total Harmonic Distortion + Noise)?

Are there certain op-amp families that are generally preferred for high-quality audio, and how do they compare to using general-purpose op-amps?

How does capacitor ESR affect decoupling performance?

JannikTechy — Tue, 23 Sep 2025 04:42:03 +0000

I often see discussions about choosing the right decoupling capacitor values, but I’ve also read that the ESR (Equivalent Series Resistance) of a capacitor plays an important role in how effective it is.

How exactly does ESR affect the performance of a decoupling capacitor in power supply filtering and noise suppression?

Are there cases where low ESR capacitors are always preferred, or can higher ESR sometimes be beneficial? What are the best practices for considering ESR when selecting capacitors for decoupling in digital or analog circuits?

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