Questions tagged [serial-bus]

The process of sending digital data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels.

Filter by
Sorted by
Tagged with
2 votes
2 answers
54 views

How to handle varying chip voltages on an I2C line?

I am working on a design where I have various chips that operate at different voltages that I am trying to put on one I2C bus. Normally I'd just pick different chips that accomplish the same goal with ...
Sal's user avatar
  • 21
0 votes
1 answer
80 views

Cannot isolate Raspberry Pi from the other circuit using optocoupler. Why not?

I'm sending data (Tx1-D) and command (Tx2-C) communication from Raspberry Pi 3 at baud rate 115200. I tried to isolate the RPi from the other circuits by using optocoupler as in the diagram but it ...
Ezzat's user avatar
  • 5
1 vote
2 answers
111 views

Help decoding unknown data stream

I'm currently diving into the task of cracking the data stream protocol for a generator control system. There's this setup with a control box sitting next to the generator, and a remote switch in the ...
JC03's user avatar
  • 43
0 votes
2 answers
110 views

How do you wire up the PCA9600 I2C bus extender to use differential signalling at 12V?

I would like to use a 12V differential signal between two NXP PCA9600 I2C buffers to extend I2C at 100kHz to about 15m over 100-ohm twisted pair (CAT6). My original understanding from a brief look at ...
KJ7LNW's user avatar
  • 1,786
2 votes
1 answer
134 views

MSP430 I2C no ACK send over Bus - updated but still not working

I'm trying to get an I2C communication with an MSP430 (MSP430G2231) working. This is the first time I'm using a MSP430 for I2C and not sure if I'm doing everything correctly. I have a Slave connected ...
ulix's user avatar
  • 183
0 votes
2 answers
42 views

How to write to a write to ADS1015 through TCA9548A connected to I2C multiplexor and trying to talk to a analog to digital multiplexor?

I am using a Raspberry Pi Zero 2 to talk through a TCA9548A to multiple ADS1015, each ADS1015 is on a separate SDA/SCL channel of the TCA9548A. I am able to scan all channels and see the active ...
user avatar
0 votes
0 answers
35 views

Serial communication - previously sent information incorrectly stored in image buffer arrays

https://github.com/StonedEdge/Retro-Lite-CM4-Dock/tree/main Hi everyone, I am trying to read in some image data over serial communications, which is done on the trigger after receiving some characters ...
StonedEdge's user avatar
3 votes
3 answers
778 views

High-speed USB 2.0 data transfer

How can I send data from an MCU at rates as high as 30 Mb/s to a PC? I can't find a suitable SWD to USB 2.0 bridge IC, so I assume there must be a better way of sending a lot of data over USB. I know ...
Simon's user avatar
  • 51
4 votes
4 answers
1k views

Can I test if a MODBUS server device is active?

We have a device which has a RS485 Modbus connection. This device supposedly acts as a server on the bus. We are in a position where it is not clear if the Modbus feature is even turned on or active. ...
James Mason's user avatar
1 vote
2 answers
420 views

What is the size of the variables declared as macros in C Programming?

I am currently trying to receive and process serial data from an STM32F401CCU6. I am receiving binary data from the STM over USB and I would like to re-assemble the raw data into what was originally ...
Harit's user avatar
  • 73
1 vote
2 answers
224 views

CAN bus message is removed when many nodes are present

Prerequisite I have one emitter sending extended message and many nodes in the bus. I am working with the emitter and the last receiver (the first and the last in the diagram), other 3 nodes are not ...
Konflex's user avatar
  • 111
0 votes
0 answers
28 views

Is it possible in Profibus DP that slaves can talk each other?

I could not understand what Profibus DP is. Is it only I/O system which is controlled with a PLC or is it a complete bus system which controls the data traffic? If the second, I would like to ask if ...
alfonso's user avatar
  • 457
0 votes
1 answer
148 views

Does SPE (Single Pair Ethernet) require termination?

It is stated that it needs 100 ohm termination resistor but is it end of the each line externally?
alfonso's user avatar
  • 457
0 votes
0 answers
21 views

What is the maximum data rate of AS-Interface?

After online search, I could not find exact information except some marketing words. It is said that it supports up to 100m and can be extended up to 600m but there is no information of maximum data ...
alfonso's user avatar
  • 457
0 votes
2 answers
143 views

Is it possible to use I2C fast mode+ with 30m cable?

I2C can reach up 1Mbps with fast mode+ and 3.4Mbps with High Speed mode. I just want to ask if it is possible to use 3.4Mbps mode with longer cable and what is the max. possible cable length.
alfonso's user avatar
  • 457
-1 votes
1 answer
101 views

What communication protocols can I use with maximum 2Mbps, with simple a simple cable (two wires, unshielded, untwisted)? [closed]

I need to find a communication protocol/module (on market product) in order to provide M2M (max 64 devices) communication at a maximum rate of 2 Mbps and a range of up to 30 m. The cables/cable should ...
alfonso's user avatar
  • 457
0 votes
2 answers
650 views

What communication protocols are used with mobile displays?

I have been researching the communication protocols used between the motherboard/processor of touch screens used in phones and smart watches for a while, but I couldn't find much. Generally, ...
omerkarslioglu's user avatar
1 vote
3 answers
233 views

Microcontroller requirements for multiple Modbus controllers

I am in the process of trying to design a circuit that will have four RS485 RTU Modbus ports, two acting as clients and two acting as servers, on which I will connect up to fifteen sensors. I am ...
Aleš Kramžar's user avatar
1 vote
1 answer
172 views

Raspberry PI4 and RS232 adapter cable: how to send serial commands

I would like to use a Raspberry Pi4 to control a syringe pump [(see datasheet here and in particular the quick start manual on page1)][1] The connector cables I used are RJ11 from the Pump to RS232 (...
Marco Bobinger's user avatar
4 votes
2 answers
618 views

MAX232 IC does not convert to and form RS232 levels

I made a simple circuit to read data from RS232 lines and print data on different RS232 lines. This is the IC I am using: MAX3232EIDWG4. The IC fails to convert the CMOS to RS232 level logic. I am ...
dreamcoder's user avatar
0 votes
4 answers
715 views

How are "async/sync" and "serial/parallel" communications related?

I think "async/sync" and "serial/parallel" are orthogonal concepts. There can be 4 combinations of communication types: async serial sync serial async parallel sync parallel From ...
smwikipedia's user avatar
  • 1,170
0 votes
0 answers
178 views

How to identify Modbus device speed rate?

In particular how to identify it without causing device misbehaving. Either new device is being connected, and master has no idea what baud rate the device is configured with (assume it knows about 8/...
Anonymous's user avatar
  • 6,930
4 votes
3 answers
3k views

Stand alone CAN bus module or STM32 embedded CAN?

I have spent days studying and trying to achieve simple communications with CAN bus from scratch using stm32f1, but I still have not achieved the desired results and it is difficult to understand and ...
Ricardo Casimiro's user avatar
6 votes
7 answers
1k views

How does the current of RS485 signals return from the receiver to the sender?

I am planning a system consisting of 1 master device which is connected to 19 slave devices using RS485 transceivers. Also, all devices are powered by 1 PSU. A simplified schematic is shown below. As ...
Michael's user avatar
  • 285
3 votes
2 answers
858 views

Alternatives to CAN for multi-master transmission

As usual these days I'm fighting against component shortage. As in completely redesigning boards since they give us lead times in the 2023 years. At the moment I have this product line where the ...
Lorenzo Marcantonio's user avatar
1 vote
2 answers
222 views

SAM3x8e can't program over serial

UPDATE: Jan 2022. I put together a new pcb. This one has the JTAG header and I have an ATMEL-ICE. Otherwise the processor and support layout is mostly the same. I stripped the program down to simply ...
J Hinton's user avatar
8 votes
4 answers
2k views

Why common-mode choke on differential-signal serial lines?

I have 2 questions: Why using a common-mode choke on serial communication lines (like CAN, RS485) if the signal is differential? Wouldn't the common-mode noise simply be cancelled in the receiver? I ...
user's user avatar
  • 83
0 votes
0 answers
187 views

Can0 return no data, but with no error

I'm actually trying to get data from a CAN on vehicle connected by DB9 on my raspberry. The DB9 provides also energy to the raspberry (here the material that i'm using). I've followed every of these ...
wajisan's user avatar
2 votes
2 answers
569 views

SPI modes of data transfer

I am learning SPI protocol in serial communications now. I got stuck with the clock phase and polarity controls concept. Why there are 4 modes available other than a single universal transfer mode. ...
CNA's user avatar
  • 665
2 votes
2 answers
126 views

Detect LOW signal in a two-way IO line that's HIGH when idle

I am trying to implement the ISO 7816-3 protocol as can be found in the EMV Co. Book 1 using an ESP32 and MicroPython. However, I noticed that the default state of the I/O line is HIGH, and there's ...
Iorpim's user avatar
  • 121
0 votes
1 answer
85 views

Serial line behaving strangely

I'm currently working on an Arduino (Mega2560 based) from Industrial Shields. Model is 21+. I use the Serial1 output (TTL 5V) to communicate with a sensor (LP8 CO2) who have CMOS 2,5V serial interface....
Prof_Sims's user avatar
  • 110
0 votes
3 answers
87 views

"<ret>" meaning?

I'm attempting to use multicharacter serial commands in this manual (page 18 in the pdf, 16 in the manual), but can't get them to work. When I'm trying to use the "GX " command to move to, ...
mattzhu's user avatar
  • 101
3 votes
3 answers
4k views

Shouldn't an I2C address be 7-bit binary?

I have a charging IC which I want to use with I2C. In the datasheet on page 31 it says that the I2C slave address is 6BH. Shouldn't this be a 7-bit binary number?
lucifer's user avatar
  • 47
3 votes
0 answers
117 views

Need help identifying weird serial protocol

I am trying to decode an embedded serial protocol. The device is a wired remote control for a crane. The controls are obsolete. I'm trying to design a new replacement one. There are a few buttons and ...
mbeau's user avatar
  • 31
1 vote
4 answers
1k views

How does I2C handle data loss?

Does I2C have any data loss prevention mechanism? If so, how does I2C recover?
Sihat Afnan's user avatar
0 votes
1 answer
363 views

Inverting Pairs in Full Duplex RS485

The following is the Full Duplex configuration for a Maxim 3292 RS-485 transceiver module. It is possible to invert the polarity of the pairs, lets say, exchange AB by BA and ZY by YZ at the Master ...
Brethlosze's user avatar
  • 1,419
0 votes
0 answers
243 views

How to record RS-485 Modbus communication at PC?

I am working on a system with an IPC, RS-485 Modbus communication, and 15 Toyo step motors and drivers. A motor frequently moves without IPC intentionally sending moving instruction and causes a ...
Superuser's user avatar
  • 169
1 vote
1 answer
420 views

Unable to install MCP2221 Driver on Win10 64bit OS

I use this PIC32MZEF board - https://www.microchip.com/DevelopmentTools/ProductDetails/dm320007. It needs MCP2221 driver tobe installed for UART communication with PC. I downloaded from official ...
Vishwesh GM's user avatar
1 vote
4 answers
335 views

Is it possible (with reasonable effort) to use ethernet hardware to provide point-to-point digital I/O bridge?

I'm interested in designing a "simple" circuit that would bridge digital inputs or outputs over a distance with relatively low latency. The idea is to take several pins from a GPIO bus like ...
M Szil's user avatar
  • 13
4 votes
1 answer
4k views

USB to RS485 converter on Linux [closed]

I have a USB to RS485 converter: It has a CH341 chip, that is all I know about it. When I plug it in, I can see that it is bound to port ttyUSB0. I want to be able to send and receive bytes from PC (...
Marcell Juhász's user avatar
1 vote
2 answers
136 views

Unable to upload anything to Arduino Uno

Any time I try up upload a sketch to my Arduino, I get the following error message: That "1 of 10" then repeats all 10 times, and ultimately fails. I know that this board works, as I am ...
Charlie Boardman's user avatar
4 votes
2 answers
518 views

What was the communication protocol used on board the Apollo moon lander?

It seems that the development of TTL was contemporary ~1961 the maiden moon landing of the Apollo vehicle, while the development of one of the oldest digital signalling standards RS232 using the UART ...
kbakshi314's user avatar
2 votes
2 answers
753 views

What kind of PLL is used to recover the clock from E.G. USB 2.0 data stream

I would like to create a communication protocol to connect two FPGAs. I would like it to be fairly fast, (a couple of 100s of Mbps) but only use a single differential pair. This kind of thing is ...
Rocketmagnet's user avatar
  • 27.2k
2 votes
2 answers
416 views

Daisy chain multiple PCB with an existing IDC cable

I'm not sure, if I just miss the obvious, but I'm stuck on seemingly simple problem and can't find a solution. I have a series of PCBs, I want to daisy chain. The number is between 8 and 12(max). The ...
KarlKarlsom's user avatar
  • 1,792
0 votes
1 answer
131 views

I2C: How does the Master recognize an ACK from a specific slave?

I just started learning about serial communication protocols. So I understand there are only two lines connecting a master and many slaves Master broadcasts the start condition then the slave address ...
Aravindh Vasu's user avatar
0 votes
0 answers
78 views

Serial communication protocols used in spacecrafts and airplanes

I always see that CAN bus is used in automobiles for communication between nodes and for on board diagnostics and basically for the overall functioning of vehicle. What are the similar serial ...
Sundar Santhanam's user avatar
0 votes
0 answers
435 views

MIPI I3C Basic Timing: Tsco

The MIPI I3C Basic standard describes an I2C-like bus with different timing requirements. In particular, that document describes a measure, tSCO, that describes a target device's clock-in to data-out ...
Burt_Harris's user avatar
0 votes
1 answer
68 views

Wired sensor bus technology

I am working on a project which requires a dozen VL53l0X I2C-TOF sensors to be polled by one master MCU over a few meters of cable. Thus, I decided to accompany each TOF by an Atmega8 acting as a ...
Daniel D.'s user avatar
0 votes
2 answers
465 views

Terminating resistor considerations for half-duplex RS-485 over 80-200 m cable at 115 kbps

I'm designing a system where we are communicating with a device (ultrasonic anemometer) which is at the end of a cable which could vary between 80-200m. The sensor communicates via RS-485 half-duplex. ...
user325107's user avatar
0 votes
1 answer
123 views

Bus communication scheme for large number of devices (255+ nodes)?

I'm trying to figure out the feasibility of setting up some type of differential bus communication for up to 400 devices outdoors. The main constraints are mainly power consumption, complexity, wire ...
Jackson Seal's user avatar