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.
156
questions
1
vote
1
answer
42
views
What determines I2C interrupt service time after address byte ACK?
I am looking at the NXP spec for I2C and what I don't understand is the timing constraint for the portion of the transmission where the "clock line held LOW while interrupts are serviced" (...
- 229
2
votes
3
answers
1k
views
What causes a digital signal to look like this?
I’m reverse engineering an existing microprocessor to microprocessor serial signal. When I put my scope on the target device I see the clock and data lines just fine on my scope when I connect it to ...
- 31
1
vote
0
answers
14
views
Data availability on a HART device network configured for multi-drop mode
We have 2 flow meters on an equipment installation that are HART-capable. As they are installed today, configuring these devices in multi-drop mode would be much easier than running additional wire ...
- 73
2
votes
2
answers
193
views
Serialised data bus using 74-series logic?
I’m looking for ways to serialise an I/O data bus write. This is for an x86 embedded system, where I have several on-board devices (accessed via I/O ports) that I want to situate some distance away ...
- 183
0
votes
3
answers
195
views
Efficiently reading states of large amount of buttons in Series on a microcontroller
I am currently working on a project that involves reading the states of 500 buttons using a microcontroller. Each button is placed on separate PCBs, with a 30cm gap between each button PCB. The ...
- 21
2
votes
2
answers
76
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 ...
- 21
0
votes
1
answer
91
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 ...
- 5
1
vote
2
answers
160
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 ...
- 43
0
votes
2
answers
245
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 ...
- 2,088
2
votes
1
answer
157
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 ...
- 183
0
votes
2
answers
59
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 ...
user298907
3
votes
3
answers
1k
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 ...
- 51
4
votes
4
answers
2k
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. ...
- 89
1
vote
2
answers
839
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 ...
- 83
1
vote
2
answers
309
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 ...
- 111