Questions tagged [microcontroller]

A device which includes a central processing unit (CPU), memory, and (generally) an assortment of I/O peripherals (UART, ADC, DAC, general-purpose I/O, I2C, etc.) in a tightly-coupled standalone package.

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6
votes
1answer
307 views

FCC verification for PCB business card?

FCC regulations apply to unintentional radiator devices, but provide exceptions for subassemblies, including this one: CPU boards, as defined in §15.3(bb), other than those used in personal computers,...
6
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1answer
427 views

GPS Power consumption MTK3339 vs SirfIII for periodic logging application

I am currently working on redesigning a SirfIII based battery operated GPS logger. A MTK3339 based GPS module has been selected due to overall (advertised) performance. The GPS logger uses a ...
4
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2answers
175 views

How to write or generate test cases(or vectors) for automated production testing of embedded electronics?

My question is following: Assuming I have developed some embedded controller(board) which has some tens of digital inputs and outputs. It has embedded firmware, which performs some logical functions. ...
4
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1answer
389 views

Interfacing TDC sensor (inductive pickup) to a microcontroller

I'm trying to do some diagnostics on a classic car (aircooled VW). In particular, I'd like to monitor a signal that flags the TDC (Top Dead Center) on every engine revolution. The signal is available ...
4
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1answer
4k views

How can I log information from code in IAR Embedded Workbench to a log file?

I'm trying to develop an application for the NXP LPC1788 microcontroller and I would like to be able to log formatted strings at arbitrary points within the source code to a log file in a way that has ...
3
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0answers
99 views

Running Application on SIM808 GNSS module beside it's internal firmware

I'm trying to load my written program to SIM808 and the module will be responsible for running my program and also its internal firmware. SIMCOM has a document about doing this in SIM800 module but ...
3
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1answer
332 views

MCU HIB pin only pulls Buck/Boost EN pin every-other Hibernation

MCU: TM4C1294NCPDT Buck/Boost Converter: TPS63051 Hib dedicated LDO: MIC5504-3.3YM5-TR I have a LiPo battery coming into the board, feeding both the TPS63051 and the MIC5504. Tiva's HIB pin is ...
3
votes
1answer
529 views

Proper way of designing a battery backup system with 12V/5V dual output AC power supply?

I have a project (doorlock) with MCU / LCD / Keypad and solenoid (lock) connected together. MCU, LCD and Keypad runs at 5V while solenoid runs at 9V to 12V. I'm currently powering the system with an ...
3
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0answers
391 views

OLED display using dspic33f i2c

I am trying to use OLED display in a dspic33f microchip. I've successfully initialized and sent data using I2C to OLED. I managed to display a small font(8pt) on the OLED. However, when I tried a ...
3
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0answers
501 views

clocking MSP430 UART from DCO

I'm designing a simple remote-controlled sensor. It's going to be connected with others and a master device using RS485. All it's going to be doing is transmitting the status of a few digital lines ...
2
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0answers
45 views

AD7730 calibration failure

EDIT: The exact issue is this, the ADC has a gain register (set during internal FS calibration and again at System FS calibration) and an offset register set during system zero calibration. The ...
2
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0answers
45 views

How to upload code to AtMega2560 using JTAG ICE 2.0

Background : I'm used to code in Arduino(Uno, Mega, Esp32, Esp8266). But this time i have to code directly on AVR Atmega 2560 Chip. I have AVR JTAG ICE 2.0 (like this one) and download several ...
2
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1answer
37 views

Reading signal from 190v magnetic pickup

I am using a magnetic pickup to detect the phase and RPM of a rotating assembly. The magnetic pickup produces a pulse once per rotation when a ferrous interrupter passes the pickup. Dependent on the ...
2
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0answers
51 views

Address Sent bit is not set on STM32F4 Disco

I am trying to interface my STM32F4 Discovery board with a sensor that works over i2c, since the sensor required a specialized i2c protocol, I decided to implement my functions using registers. But ...
2
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0answers
79 views

Embedded design with USB 3.1

I am trying to design a system that will transfer data between two storage devices on a PCB, preferably using USB 3.1 as speed is a major concern in this design. However, my understanding is that I ...
2
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1answer
68 views

Why does writing to a read-only register increase current consumption?

Looking at the datasheet of the MSP430, it says writing to read-only registers results in increased current consumption. Why is that? What is happening when trying to write to a read-only section of ...
2
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1answer
332 views

Confused about the XIP (eXecute In Place) function of QSPI FLASH

There are lots of NOR QSPI FLASH chips that support XIP (eXecute In Place). In this mode the embedded cpu (or MCU) can directly execute the codes stored in the flash. But as we know, the qspi flash ...
2
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1answer
53 views

Preventing inadvertent feeding of an external watchdog

Most internal watchdog timers found on microcontrollers contain mechanisms to prevent an inadvertent feed, usually requiring the write of a specific key-value to the feed register, although some ...
2
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0answers
197 views

BDM (Background Debug Mode) with Arduino

I'm trying to talk to a 68HC(9)12D60 (Motorola/Freescale/NXP) via BDM protocol. This chip is a 112-pin TQFP. On the PCB, there is a 6-pin header (which is not the standard BDM 2*3 pins header). The 6 ...
2
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1answer
230 views

Programmable Electronic Load Design

I am trying to design a programmable electronic load for testing the PWM outputs of PLC controllers. The outputs operate between 5-36 V and 10-2000 Hz frequency. The output is supposed to tested for ...
2
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2answers
124 views

Timing a circuit's 'on-cycle' after a push button switch is pressed

First off, thank you for reading all of this - you are the part of the internet that gives me hope for mankind. I’m looking for a circuit that I would think is relatively straightforward, but has a ...
2
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0answers
117 views

Write to File in Computer running IAR Workbench

I am currently writing and testing an embedded system in which I need to collect data from an accelerometer over a period of time. I already have functions that can read the data at a point in time ...
2
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0answers
107 views

Can a PC motherboard be used as an uber microcontroller?

I'm aware of the differences between a common microcontroller and a full blown motherboard from a computer server. But consider what happens when the PC memory testing tool memtest86 is run:- Here ...
2
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2answers
822 views

STM32F0 ADC reads wrong values

I am using STM32F030F4P6 MCU for a project. This MCU has no Vref+ pin and using VDDA pin for A/D conversions, PLL etc. While prototyping the circuit that I am going to use on my project, I shorted ...
2
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0answers
54 views

Audio Sampling for Reactive Lighting

I'm trying to work on a reactive lighting project and I'm confused about a couple topics when it comes to sampling audio. I want to be able to have RGB reactive lighting controlled by a ...
2
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0answers
429 views

My First Circuit Diagram - How to improve it

I started taking more of an interest in micro-controllers and electronics last year, I started to design a circuit (which I hoped to have created as a custom PCB - Though I don't know how to go about ...
2
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0answers
129 views

DC motor speed control

I am trying to control the speed of motor using ADC value received using ATMega16, the system works well with 12V. But when I go for 24V the motor runs continuously, even when ADC value is 0. I have ...
2
votes
2answers
234 views

Momentary switch for power?

The only switches I have every worked with are basic switches with on/off state, but I want to be able to add a power button to my project that is just like the power button on a cell phone. (hold for ...
2
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0answers
130 views

How to create a Program Log in Readable format

Im looking for a way in which the program can log specific errors/conditions(user-defined) as and when such conditions occur, and while the code is running I can give command to read it and interpret ...
2
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1answer
177 views

How to reduce the effect of electric lighter noise on Micro controller?

I am using a kind of electric lighter in my circuit in order to turn the fire on. And also i have used some sensors that alert in danger by sending a signal to the MCU (ATmega 32) interrupt. The ...
2
votes
1answer
221 views

PIC16F1783 Inclinometer Project using Accelerometer 12-bit ADC issue

I am working on an inclinometer project using an accelerometer, MMA1220KEG and a PIC16F1783, it is designed to switch a relay when the angle of inclination is below 15 degrees and illuminates a series ...
2
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1answer
602 views

Interfacing SIM900A GSM Modem with TM4C123G TI microcontroller

I was hoping you guys could help me on connecting SIM900A GSM Modem with this TM4C123 micro controller. I connected the RS232 ports of TX, RX, GND and power ports to GND and +12V. should I connect ...
2
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0answers
103 views

PIC32MX350F256 Errata , IO open Drain Issue

In one of our Product we used Microchip micro controller “ PIC32MX350F256L”. Attached image is small part of circuit showing uC interfacing with a SPI device. We are using bit banging communication ...
2
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0answers
524 views

Microcontroller on/off circuit in battery power device

I am using the below circuit to turn ON and OFF my load microcontroller circuit in my battery powered device. The max current draw I'm expecting is around 800mA. My logic is like this. For power up ...
2
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0answers
292 views

Strange behaviour using PWM on CortexM3

I have a board with the ATSAM3S2BA-AU, which is a Cortex M3 uC. I need to use 2 PWM channel , here how I've done it : ...
2
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0answers
433 views

Is there an online resource for finding microcontroller with specific requirements?

When looking at digikey with the advanced search chrome extension (Link) on I noticed that some features of the microcontrollers are not recorded (such as MIPI, PCIe, UBC, etc). Is there a website ...
2
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0answers
5k views

How to get an ENC28J60 to work?

For starters: Yes I know I'm about to reinvent the wheel with the following task ahead. I want to create my own library for the ENC28J60 for an AVR (ATMEGA1284P). So I've been browsing the net for ...
2
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0answers
695 views

AVR: Usage of Force Output Compare bits

Currently I'm dealing with Tiny2313 for my project. Timer runs in CTC (WGM12) mode so OCR1A is used to set TOP of the timer. I want to use OCR1B to generate output signal. In documentation is ...
2
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0answers
304 views

Float calculations hangs on Kinetis K20 (arm-m4-no-fpu) when PWM interrupt is on

I will use this ARM to control Induction Motor with three-phase inverter. When the program encounters any float operations, like simple plus operation, the system hangs but the pause of debug works ...
2
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0answers
3k views

Constructing Excess 3 BCD to 7 segment decoder - circuit hints needed

I am currently trying to construct a circut for an Excess 3 BCD to 7 Segment decoder. Therefore the input range ranges from 0011 to 1100 in binary inclusive with the rest of the inputs being don't ...
2
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0answers
794 views

LIS302DL Accelerometer WHO_AM_I command

I've setup the behaviour of LIS302DL accelerometer IC using following code: ...
2
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0answers
490 views

Data logger using ARM 9 (Friendly ARM Mini 2440 kit)

I have been working on this kit for the past month and have simulated some basic programs using Keil (non os using just C). I was assigned a project of making a data logger which stores the data in ...
2
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0answers
261 views

Are there any metastability issues with microcontroller SPI slave ports that can operate during sleep?

If one is using SPI to interface two microcontrollers that may spend much of their time sleeping, and if the SPI slave port is supposed to wake up its controller when data is received, that would ...
2
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0answers
116 views

Generate audio driver hi current from MCU & DAC

I am very very new to microcontroller use. I am looking for a way to generate 2 different VLF frequencies that alternate for set time periods that will be pushed into an audio amplifier device to ...
2
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1answer
92 views

UART stop bit baud timing error

On PIC micro controller UART, Baud rate was set to 38400 (No parity,, 8 data bits), ...
2
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1answer
203 views

How to connect four different ground planes in the same PCB?

I am working on a project which uses the LTC4020 multi-chemistry battery charger from Linear Technology. The design includes a microcontroller ( NXP KL25Z) to provide additional outputs and ...
2
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1answer
550 views

Shut down circuit sections

I am currently devising ways to shut off different circuit sections in an embedded circuit. Here is a breakdown of what I am doing and my initial idea. Currently I have a micro controller which is ...
2
votes
1answer
546 views

PIC32MX can't get 80 MHz Clock from Internal RC OSC

I am using PIC32MX795F512L with the internal RC oscillator. By changing the settings of the config, I can get to 60 MHz max. But I can't get to 80 MHz. When I change the config for 80&#...
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0answers
44 views

Applying a 1/3 bias to an LCD display spec'd at 1/2 still safe?

We're currently using an MSP430 with an integrated LCD controller that only has a 1/3 bias mode. The LCD display has a 2-mux configuration and the data sheet specifies "drive method: 1/2 duty, 1/2 ...
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0answers
70 views

Flaky GPIO on ESP8266, how do I solve it?

I have an ESP8266 where I took one of the GPIO pins, configured the pullup on the input, then connected it to one lead of a 15m cable and the other lead to the ESP8266 ground. The problem I have is ...