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.
2
votes
1answer
40 views
How would I place CAN termination resistors in a 3 ended configuration?
I have a project for which I have one central circuit board which has a can node on it, this central circuit board has three connectors on each of which a node could or could not be plugged in with a ...
0
votes
2answers
57 views
Maximum Switching Speed Chained 74HC595
I'm planning to use a set of daisy chained 74HC595s to control a set of 108 mosfets, 3 of them are geographically in the same area (couple of mm apart) and for the sake of modularity should each use ...
0
votes
2answers
115 views
RS485 vs RS232 similarity vs differences
I have used UART RS232 communication between MCUs extensively. Now I need to interface my STM32F407 MCU over RS485 bus with with devices. I have understood few things about RS485 but not-clear about ...
1
vote
3answers
248 views
Direct connection of UART serial port to USB type-C
in my project I have a USB type-C 3.1 2nd Generation (24 pins), which should provide 5V to a charge battery/battery system. In addition, there is a uC powered at 3,3V where the maximum voltage on GPIO ...
0
votes
2answers
75 views
How to select the most appropriate (serial) bus for controller?
In the context of a robotic project where different 'payloads' and/or robotics arms (end-deflector) should be mated mechanically with power, data and control connections support, I would like to ...
0
votes
1answer
105 views
What does it mean when i2c_smbus_read_byte() returns 0
i2c_smbus_read_byte() returns a negative value when there is an error in reading data. But what if it returns 0?
Following is the code from adt7316-i2c driver
...
0
votes
1answer
91 views
How does this serial input DAC work?
This is the datasheet for 6379A:
datasheet
I looked at the timing charts, but I’m still having trouble figuring out how the IC treats the serial input.
Apparently, SI is sampled at positive clock ...
2
votes
1answer
104 views
Daisy chaining I2C modules using CAT5 and P82B715
I'm planning to connect several modules over I2C with distances between modules ranging 30-180 cm. I understand that in order to avoid the degradation of the signal due to the capacity of the ...
1
vote
1answer
110 views
MAX485 suddenly drawing too much current and output voltage levels are not right
I have two PCB that I designed and they are made by a PCB manufacturer (so they are identical). They use a MAX485CSA to communicate but suddenly one of them is drawing too much current, on a normal ...
0
votes
3answers
523 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, ...
1
vote
2answers
952 views
Switching RS-485 bus
As shown in the graph, I'm trying to use mcu-controlled switches to turn a segment of rs-485 bus on or off (so that only one segment is on at a time). I was considering analog switches but I'm not ...
0
votes
1answer
253 views
ESP32 AND CP2102 Serial data reading issue
I have a PCB on which i am taking a 5v - 1A DC power supply , and again providing 3.3v to ESP32 through AMS-1117 3.3v.
Basically things are not working on when i solder the esp32 on my pcb but things ...
0
votes
3answers
89 views
Data transmission over up to 100 ft
I need to transmit data (less than 5Mbps) point-to-point over 100 ft. I prefer not using Ethernet due to the complexity. I can use low-scale FPGAs or similar chips if needed for functions like error ...
0
votes
1answer
144 views
UART to a old Foscam Camera
Not a long time ago, my outdoor security camera stopped working. It was a foscam, the closest product that I could find was : https://www.foscam.com/product/47.html
However, my camera is an older one, ...
1
vote
2answers
154 views
2-wire MPU interface / 2-wire Serial Control Interface?
While reading datasheet of an audio codec IC, I got confused over the term "2-wire MPU serial interface". Is that just another term for I2C (just like TWI or TWSI) and they are fully compatible? And ...
-1
votes
1answer
132 views
Avoid reboot of USB serial device when another USB device is inserted [closed]
EDIT 7/7/2018:
Can't add an answer because this question is closed however there is an answer here.
It is not a problem related to Windows only. The reset is caused by hardware behaviour, the ...
0
votes
1answer
68 views
Suitable 12VDC Communication protocol for untwisted unshielded long-ish wire length?
What would be a reliable and simple tranceiver interface/protocol for board to board serial communication at about 100ft. [9600bps or lower is fine.]
The two-lead communication wiring cannot be ...
0
votes
2answers
60 views
Quantifying Eye Diagram for high-speed SERDES channel
I need help quantifying Eye Diagram. I have to quantify Eye Diagram at the end of my Thesis for my Serial Link channel. Viewing an Eye Diagram, I can say probably whether it is bad or good. But for ...
0
votes
2answers
295 views
One master to 32 slave pic microcontroller communication, bitbang
I'm trying to communicate with 32 microcontrollers (PIC 12f675). These are used to control 32 DC motors and 2 sensor for each PIC. So only two pins are left to communicate with master device.
I want ...
1
vote
1answer
582 views
I2C bus extender
I am working on a project which requires a long I2C bus which can be long as 200m or more.I searched on the internet and found a chip nxp PCA9600.I would like to know is there any alternate for this ...
1
vote
2answers
277 views
Reliability of Serial IO Expander like MCP23S17
Background:
I am doing a re-design of an existing system moving from HC11 base with memory mapped I/O to an ARM Cortex-M3 with serial SPI/I2C I/O (opto-isolated inputs and relay outputs). I/O access ...
0
votes
2answers
161 views
Serial communication protocol [closed]
I want to learn about the raw serial communication protocol (The one that uses the Rx and Tx pins of a microcontroller).
I want to be able to send bits of data without using a microcontroller.
How ...
0
votes
0answers
70 views
12 bit asyncronous USART using pic (rx)
I need to implement an asynchronous receiver USART. The length of the frame is 12 bits.
I looked into implementing this with a pic 16F1455 but it only supports 8-9 bits: "Programmable 8-bit or 9-bit ...
2
votes
4answers
1k views
Decoding message data on this CAN bus
I am working with the CAN bus and need some help with decoding message data.
Here is a sample of the data that I'm seeing on the CAN bus.
...
1
vote
1answer
645 views
Where is the benefit in SQI parallel interface over SPI? Parallel vs. serial
Microchip is offering a number of serial SRAM chips with a communication protocol called SQI which is similar to SPI but with 4 parallel bits written at each CLK toggle.
If you can spend the extra 3 ...
7
votes
3answers
898 views
Is RS-485 a suitable physical layer for Atmega chips in a home monitoring situation?
I am intending to build some Atmega based home monitoring chips. I want to monitor temperature, humidity, and current levels. Current level monitoring would be done with an inductive pickup on AC ...
2
votes
2answers
576 views
Why would credit card reader over audio jack not work on some devices?
This isn't a troubleshooting question, it's purely to satisfy my curiosity...
MagTek makes a product called the uDynamo credit card reader that uses the audio channel on android devices as a ...
-2
votes
2answers
254 views
usb to rs232 serial communication
I have to configure my rs232 to device(transmitter) using usb to serial communication. I have tried with usb to rs232 cable and connect the transmitter 6 pins to the db9 connector but it did not work. ...
0
votes
3answers
452 views
LCD interfacing Issues: Embedded Systems
Hobbyist tend to use parallel communication for interfacing with an LCD and all the libraries are for a specific type of microcontroller (Arduino or AVR) or LCD.
But, for a design engineer, it is ...
0
votes
1answer
746 views
FT232RL USB to serial : 5V or 3.3V set by jumper
I've just bought a cheap FT232RL USB To serial adapter (EAN: 0680004529143). It does not come with a manual and the short description simply mention:
USB power supply, can choose 5V or 3.3V ,set by ...
0
votes
1answer
251 views
Tool or method to listen to a custom RS485 bus traffic
How do I listen to a CFLink bus for data? The said bus was implemented on top of RS485. I've tried hooking it up using an RS485 to serial adapter and RealTerm but I've got nothing returned even though ...
5
votes
4answers
252 views
Device discovery on simple bus
I am currently facing following problem: there is a system, which consist of one master device and some number of slave devices (all those devices have tiny MCUs). They communicate with some custom ...
0
votes
2answers
40 views
How to feed 2-state voltage into PC?
I have a simple circuit that generates +5V under normal conditions but goes down to 0 when something is wrong. I need to feed this voltage into a PC (running Ubuntu) and write a program to monitor the ...
0
votes
1answer
1k views
Quad SPI - Serial or parallel [closed]
Question: Is Quad SPI really a serial interface, a parallel interface or both?
The image below depicts that independent databyte may not be able to send over individual lines (I see databits spread ...
-1
votes
2answers
227 views
Standard cables for modbus protocol
What are the standard cables I can use for modbus protocol?
lease add the price details if anybody knows
1
vote
3answers
96 views
If serial ports are asynchronous, why do they have an SCL line?
For instance, this tutorial has these two seemingly contradictory quotes:
Because serial ports are asynchronous (no clock data is transmitted), devices using them must agree ahead of time on a data ...
4
votes
3answers
446 views
What does this bus signal representation mean?
Often, when looking at digital system signal plots over time there are these graphs with two parallel lines that often "swap" place. I am wondering what precisely they represent? I noticed they ...
3
votes
3answers
369 views
Are there standards for digital sensor links?
Following this question, @curious_cat had more questions in comments that deserve a proper Q here:
Is there any standard encoding that has evolved on the digital encoding side? Just as 4 to 20 mA ...
6
votes
2answers
753 views
Why are there sensors that encode their readings as serial sequence of PWMs?
This is a comment of @CuriousCat, but I think it deserves the attention of an actual question:
The sensor used in the original question outputs a serial PWM-style signal like this:
What's the ...
0
votes
1answer
71 views
How do I know if the serial cable is plugged in the right way?
I recently got a LeddarTech Leddar One rangefinder, which has a UART serial connector. I'm used to boards denoting the pinout directly next to the pins, but the only distinguishing mark on this board'...
1
vote
1answer
502 views
SERIAL/USB Game Controler Reverse engineer
I recently acquired a Logitech Wingman Formula Force from a thrift store. This controller is marketed as USB or Serial port. By default the controller ships with a native serial connector, but then ...
13
votes
4answers
4k views
Why is the serial connection faster than the parallel connection? [duplicate]
As a software developer the concept of parallel processing usually meant faster processing because it meant things don't have to wait for the other processes to finish if they don't need to.
So how ...
2
votes
1answer
419 views
18bit Serdes - Xilinx Spartan6
In a project with FPGA stereo vision I use two MT9V032 cameras. The cameras are connected as in the application example in the data sheet.
In stereo output mode the data length is 18bits long. There ...
1
vote
1answer
734 views
Physical wiring architecture for a CAN Bus
I want to wire a CAN bus for multiple motors(BLDC) in robotic arm. I am building out my motor such that they have a controller and a CAN transciever built in. There will be upto 6 motors with the ...
2
votes
1answer
610 views
SN65176 RS485 contention
I am transmitting RS485 via:
Mono application -> Linux USBTTY device -> RS485 adapter with an added 100R terminator -> ~1m CATV -> SN65176 with an added 100R terminator -> PIC.
Via debugging I am ...
1
vote
1answer
1k views
Start Bit and Idle Data Line?
I am learning the Serial Communication without much EE background:
The article says:
The start bit is always indicated by an idle data line going from 1 to
0, while the stop bit(s) will ...
1
vote
1answer
1k views
Max 485 auto transmission
i am using Max232 and max485 to convert the RS232 pc data to RS485. I got a circuit using these ICs with a transistor and some resitor. circuit is such that RE and DE are short together and tied to ...
3
votes
1answer
85 views
Switching Serial Connections among several devices?
I have 3 devices that communicate via a serial port. Let's call them Device 1, Device 2, and Bluetooth (BT to serial adapter). The BT is used to communicate with a computer, but it can be treated just ...
1
vote
1answer
907 views
Chaining Multiple USB Hub Controllers for Serial Interfacing
I have a need for a large amount of serial I/O from a desktop computer in a robotics application. I considered using all off the shelf parts with a large set of USB hubs and usb to serial adapters, ...
1
vote
0answers
426 views
Protocol used by tankless water heater remote control
Edit: see my main thread here Reverse-engineering asynchronous serial protocol for EcoSmart Tankless Water Heater
I'm using an EcoSmart ECO 11 electric tankless water heater in a hydronic system.
...
