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Questions tagged [serial]

In serial communication data is transmitted as a sequence in time. Main advantage: much less wires needed. Main disadvantage: Higher bandwidth for the same throughput.

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How to disable arduino Hardware Serial Rx Interrupt Properly

Intro: I have an Arduino mega doing multiple tasks , from which A function Reads data from a sensor using SPI . Every like 10,000 read or something , i get 1 error bit in the SPI data . and I have ...
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45 views

SPI terminology confusion for project

I am working with the FET335xS-II OBC developed by Forlinx for a school project. On the data sheet, There is no indication of pins pertaining to MOSI and MISO but instead "data 0" and "data 1". I am a ...
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1answer
69 views

ATmega328P running on 3.3V using a CH340G as serial to USB interface

I'm trying to use a CH340G chip with an ATmega328P that is running on 3.3V to have a simple serial to USB interface. The available datasheets for this chip seem to be very minimal so I've tried ...
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1answer
134 views

PIC32MX UART Interrupt Not working

I am writing a program to send data from one microcontroller and receive the data using on another PIC32 microcontroller and display the received data on LCD. I am using UART2 of both PIC32MX to send ...
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2answers
30 views

No negative terminal in power supply

I'm working on a project that relies on the Roomba vaccum cleaner's reference document (shown below), there are two positive terminals and 2 ground terminals. I'd like to understand: Why there isn't ...
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89 views

Analog Potentiometer Output to USB Serial [closed]

I‘m working on a project which has several switches and potentiometers that will be used to control parameters in software via (e.g.) MIDI and would like to know how to get the pots set up without ...
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3answers
135 views

What is this connection of resistors? Parallel or serial?

How i can simplify this electric circuit?
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1answer
81 views

Arduino serial communication hacking

I recently bought a Chines massaging chair hoping i can intercept the serial communication between its wired remote and the chair itself, I've cut the wire and connect the Rxd and Txd of the chair to ...
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120 views

How does GSM Module store incoming SMS in its “SM” or “ME” memory?

I am using AI Thinker A7 GSM/GPRS/GPS Module demo v7.1.(The Rx, TX, GND pins of this module are connected to tx, rx, gnd pins of the prolific Rs232-TTL converter and a virtual com port is open in ...
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20 views

Checking HM-TRP radio adapter for initial data

I have several HM-TRP radio adapters (consisting of the HM-TRP chip with a female header connected to it) of the same version. I tested it in a mini circuit where the PC does direct I/O with the HM-...
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52 views

Serial communication between raspberry and laptop not giving right values

I want to communicate between a Raspberry Pi 3 model B and a laptop using a USB to RS-232 cable and this RS-232 to 3.3V TTL converter via the serial module in Python: GND is connected to board pin #6 ...
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1answer
157 views

Identify this open collector serial protcol

I'm trying to analyze the serial link between two devices, respectively a motor controller board and a Li-Po battery manager, which battery powers both devices. The application is a battery-powered ...
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33 views

Lower wattage of IR bulbs permanently

I have two 90w/12v infrared IR bulbs which is put into a r7s sockets. From thes socket goes in total four wires which is connected to our power supply. We have set two of the wires in serial so they ...
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1answer
40 views

Position of leds in the RX/TX portion of an arduino compatible

Given the following circuit , electrically speaking makes any difference the position of leds? I know R8 and R9 are used to allow the override of the RX/TX pins if any other device is connected, does ...
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1answer
73 views

Is the following USB connection possible: Host USB to converted to serial (FTDI) and then converted back to USB (FTDI)

I am trying to connect a host USB device on one board to an endpoint USB device on another board, but I am required to send the link between the two devices as a serial (UART) connection between the ...
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56 views

How to use 3.3 V FTDI Serial Cable with LeMaker Hikey 620 which has 1.8v UART signals

I have FTD Serial Cable TTL-232R-3V3 which operates on 3.3V. https://ftdi-uk.shop/collections/usb-cables-ttl/products/ttl-232r-3v3-2mm I was trying to use it on my Hikey LeMaker for an hour with no ...
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1answer
108 views

PIC32 receives/transmits improper data on serial port

I have referred http://microchipdeveloper.com/harmony:example-usart-dynamic-wf32 to configure the UART and send/receive data between PC(Putty) and my PIC32MZ. The demo program in the link receives ...
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1answer
176 views

Is there a standard describing the UART data frame protocol?

The "U" in "UART" stands for "Universal", but I'm having trouble finding any standard that describes the framing protocol that's used in UART; e.g. the start bit, stop bit, parity options, and baud ...
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167 views

Long distance (and I think low frequency) serial communication with Arduino [closed]

I need to implement a long distance (up to 15 kilometers) communication between some electronic devices. The devices is some boards on AVR chips with Arduino library and a Raspberry pi as the ...
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1answer
192 views

I2C driver for MSP432

I am trying to develop a I2C driver for MSP432. As of now, I am interfacing a accelerometer through USCI B2_ module on MSP432. The problem that I am facing is I am getting a NACK in the IFG register ...
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2answers
102 views

LIN to RS485 and back to LIN

I am currently communicating between two microcontrollers using a single pin and the LIN protocol over a short distance of 0.2m. Now I would like to extend the distance up to 5m by differentially ...
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1answer
39 views

Trying to read the data from an ASK RF transmitter

I'm trying to duplicate the operation of a simple RF remote control (for some remote power outlets). In the remote control there is an unmarked 8-pin microcontroller. I've worked out which pins are ...
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1answer
99 views

Bit rate of uart communication

I have a setup which communicates between PC(windows) and Atmega2560 using UART. On PC side I am using Pyserial. From the PC I am sending a paragraph of text byte-by-byte to Atmega2560. The UART ...
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1answer
186 views

FTDI USB to serial communication issue

I am using an FTDI USB to Serial cable to read the startup log of a board. The FTDI cable is not reading the correct information coming from the board. Here is some of the information that I am seeing ...
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48 views

minimalist serial port addon to a basic 8052

Currently I have two microcontrollers connected to each other so that I have two serial ports. One to the PC and one to a wireless radio module. Now I'm considering replacing one microcontroller with ...
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3answers
121 views

What exactly are low speed devices? [closed]

The definition of I2C is - "A multi-master multi-slave serial bus used for communication between low-speed devices". However, I have been searching the web for a concrete explanation for this but ...
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1answer
45 views

Weird level shifting issue only when connected to IC chip

I'm connected to a 5v heat-pump to control it via serial. I'm using a level shifter to shift between the two as the heatpump is 5v and the D1 is 3.3v shown in the scope images below. My issue is I can'...
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3answers
617 views

Is the ATMEGA328P's serial baud rate quantised?

I'm using an ATMEGA328p, running from its internal oscillator (divided by 8 = 1MHz). I've (roughly) measured the oscillator output, using my Salae logic analyser, as ranging from 960KHz to 1000KHz, ...
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2answers
1k views

Why do we need bit scrambling when using 8b/10b?

I want to ask the opposite of this question. Here are the purpose of the bit scramblers: Encrypt, but LFSR (and other used) bit-scramblers are breakable. Clock recovery, but it is done by the 8b/ ...
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0answers
63 views

Offset QPSK Frame sync markers

What actual protocols exist out there that employ Offset Quadrature Phase-Shift Keying (OQPSK)? What do they use for the frame synchronization marker (or "preamble" or "sync word" or "flag")? Do ...
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1answer
22 views

Variations in RFID USB Serial reader detection distance by connected device

I have a RFID reader that sends the TAG information over USB serial. I have had some troubles with it in a product where the detection success rate changes alot depending on what the USB RFID tag is ...
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1answer
72 views

One Wire, 1-Wire, SingleWire, SDQ — are they compatible?

There are at least three different manufacturers with "one wire" type memories: Maxim/Dallas has "1-Wire" Microchip has "Single-Wire" TI has "SDQ" Are they all compatible with each other? I'm ...
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1answer
98 views

PC to Rasberry Pi Serial Communication

Im trying to communicate to my pc using my raspberry pi using a software called Docklight. I'm using a serial cable (that i ripped apart) and my breadboard as shown below. Now, you can also see I ...
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1answer
663 views

Why do some Arduino-compatible boards provide a crystal for the CH340? [closed]

I have an uno-shaped Arduino compatible which uses the CH340(G) serial to ttl converter chip and it is connected to an external crystal. I also have nano shaped compatible which uses the CH340(C) ...
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1answer
113 views

PISO shift register to USB

I have ~26 parallel inputs that I would like serialize and send to a computer over USB. I decided to chain together 4 LS165 parallel-in serial-out shift registers, but I don't know how I would send ...
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1answer
68 views

Same serial command, different serial replies

I have a device (a traffic counter) that communicate with my computer throught Serial Port. To extract data from this device, I use a specific software. I'm also using a Serial Port Monitor to check ...
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3answers
447 views

Why do we use a DB9 connector for serial com?

We only use 4 wires (pwr, common, and two data), so why does rs232 use such a big connector?
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0answers
205 views

stm32f103 - 16 bit mode SPI reading returns 0xFFFF

I am working with a sensor which communicates through SPI. I am trying to read MISO line, but it returns 0xFFFF. first I send 0xC000 on MOSI and the sensor places 0x0032 on MISO. I read MISO using ...
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0answers
336 views

Custom Arduino powered board (CH340C) Serial Problem

I made this custom board that contains a complete arduino nano on it. I soldered every component with extreme care and already check all the connections and they all go according to the designed ...
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1answer
122 views

Arduino Fails to Program Custom NRF52, But Has Worked In Past

Background: I have a custom board that consists of two PCBs connected via a 100mm Picoblade connector. The "Aux" board has a USB port, and CP2102N Serial=>USB converter. The "Main" board has an NRF52 ...
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2answers
117 views

Data over DC Power, mono-directional, simplest circuit

(To preface, I will probably just run 4 wires, with RS485 on 2 and power on the others, but this came to my head, and I started thinking about it.) I was thinking of a simple way to send simple low ...
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3answers
561 views

How to find out whether serial standard is RS232 or TTL when stated as “serial(RS232/TTL)”

I am recently moving from C programming into automation engineering. I have learned about RS232 and TTL standards, and I understand that they are based on the same concept of serial communication, ...
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1answer
206 views

Using Adafruit Trinket M0 (SAMD21) as a USB to Serial converter

I wanted to know if it is possible to use SAMD21 as a USB to Serial converter like the usual FTDI chips ? If yes could you please point how to achieve that. I believe that Adafruit Trinket was used ...
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1answer
145 views

Enabling and disabling serial device connected to the Arduino HardwareSerial by software

I want to use the hardware serial port (pin 0 RX and 1 TX) to connect a MAX485 IC. Internally these pins are also connected to the onboard USB to serial converter microcontroller which is used to ...
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1answer
109 views

Do I need an impedance controlled connector for RS422?

I've never implemented RS422 before (crazy right?). Since the impedance of the line is controlled to 120Ω do I need an impedance controlled connector for that? If anyone has implemented RS422 which ...
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1answer
64 views

Adapting an older schematic for use with recent components: How might this circuit need to change?

The schematic below is a bidirectional bluetooth-to-infrared serial device. Computer sends bits to device via bluetooth virtual COM port. Device re-transmits bits via 950nm IR w/ 38khz carrier ...
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1answer
110 views

Why is a new 16550 $4? [closed]

I can't imagine that the 16550 hasn't made back its design costs by a factor of at least 10 by now, why does it cost $4.32 in quantity? That makes no sense. http://www.ti.com/product/PC16550D/...
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1answer
592 views

Can I covert a 3.3v/5v USB TTL Serial device to 1.8v using a LM1117 1.8v regulator?

I have a HDD which has serial access but needs 1.8v TTL serial. I only have 3.3/5v serial devices. The standard PL2303, A UART Usbbee, and a generic serial adapter. The PL2303 & generic have 3v/...
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2answers
1k views

What is difference between USB and TTL? [closed]

I have one question about USB and TTL. Both USB and TTL works on the same voltage range (0 to +5 V), both are serial protocols. From my point of view, they are the same. Why then we have USB to TTL ...
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3answers
157 views

How can I see an output from SCL?

I am new to electronics, circuits, etc. Currently I am reading I2C and synchronous serial communications. As I understand, two devices must be connected to the same CLOCK wire so that the slave knows ...