Questions tagged [1-wire]

1-Wire is a microlan protocol developed by Maxim-Dallas, similar to I2C and SPI, but using a single Data/Ground pair. Typically includes Parasitic Power on the Data line, through the use of strict communication timing.

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33 views

How can I quickly make a long string of 3-pin components?

I prepared a 7 m long strip with 7 DS18B20 and, lacking a better idea, I soldered the DS18B20 pins directly to wires, where all but the last sensor have a 3-point star connection: DS18B20 leg, wire to ...
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3answers
125 views

STM32 USART 1-wire communication

I'm fairly new to embedded developping and I'm trying to read and write to a 1-wire device (DS18B20) using USART. After digging around I found two alternatives: Connecting USART RX and TX pins with ...
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How can I remove the return paths for a series of circuits and still know when they are completed? NFC/RFID? Multiplexing? Goubau line?

Apologies for the vague title. And know that my electronics knowledge is rather limited. Also my circuit diagrams may be incorrect. I currently have something like this, which represents contacts on ...
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48 views

Why is the 1-wire pull-up resistor not integral?

I've read that the 1-wire pullup resistor is included so that either the master or the slave device can pull the line low in order to communicate. Makes perfect sense: if the device had a transistor ...
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1answer
33 views

1-wire interfacing with motor (design suggestion and review)

For my application, I need to deploy many sensors and a motor. So I chose the 1-wire bus protocol from Dallas/Maxim. Also, I am using temperature sensors which support one-wire protocol. So I thought ...
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1answer
71 views

STM32L4 μs delay

I am trying to implement a onewire protocol on an STM32L432KCU, so I need quite precise timing (need delay precise as 2μs). I was wondering if there is any way to do this using the HAL drivers (...
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70 views

Embedded system with hot swapable sub modules

I am designing a embedded system where a master microcontroller (or possibly a SoC) needs to communicate with several different sub modules with a microcontroller of their own. The sub modules should ...
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2answers
43 views

1-wire differentiate read from write

I've been reading documentation on 1-wire and I think I'm having a brainfart. How does the slave differentiate a read slot from a write slot? reference: https://www.maximintegrated.com/en/app-notes/...
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32 views

More than 1-Wire interface (SWI) (ex DS24132) discovery and identifications

Just started experimenting with 1-wire (SWI) communications. I am currently waiting for my DS2413 and iButtons to arrive. I have been searching for information and there are lots of examples. My ...
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93 views

Noise filtering circuit on a pulled-up 1-wire bus

The 1-wire bus data line is connected to a microcontroller pin (through a level shifter) with open drain configuration. The bus is pulled up to 5 Volts (DVDD) with a 4.7k resistor. The communication ...
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1answer
165 views

How to monitor one wire “kind of” protocol

In the current network, there's 1 master device, which gathers data from over 20 devices. Nameplate says the baud rate is 2400. In the bus cable there's one data wire, 12V and GND. A friend of mine ...
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156 views

DS18B20 temperature sensor with Attiny25

I would like to make a simple thermal switch with attiny25 but first I need to read the temperature values from the ds18b20 sensor. I found some codes, here are the sources: DS18B20 lib UART lib I ...
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115 views

Practical Limitations to 1-Wire Communication Speed [closed]

What are some practical limitations to the speed of a 1-Wire interface?
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connecting 1-Wire device powers off wemo d1 mini

I have a wemos D1 Mini (an ESP8266 chip) which I am trying to connect to a 1-Wire temperature sensor. However when I plug it in the 5v or ground it seems to power off the device, this happens with or ...
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2answers
257 views

Difference between Enameled Aluminum Wire and Enameled Copper Wire [closed]

What's the different between enameled aluminum wire and enameled wire? How to choose a professional enameled wire manufacturer? Advantages of enameled copper wire? Advantages of enameled aluminum wire?...
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4answers
586 views

Raspberry Pi Zero connection to sensor (with I²C or SPI bus interface) over a large distance

SUMMARY: Here is what works: Raspberry Pi (I²C) <-> 1 m cable <-> sensor (I²C) Here is what I'm trying to do (doesn't work, hence question): Raspberry Pi (I²C) <-> 30 m cable <-> ...
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DHT22 needs electrical reset?

Context : Building a wireless sensor based on ESP8266 + DHT22 (+ "X-8266" board) + DHTtester example progam I fell on a rather strange and annoying problem : Problem : When powering up the board ...
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1answer
254 views

Practical way to splitting CAT5 for 1wire?

I'm planning Raspberry Pi system using One-Wire with thermometers (ca 10 pcs). My electrical skills are basic. I'm looking for a good way connecting stubs to main line. . The main line (green) 1 ...
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963 views

Serial bi-directional (one-wire half-duplex) digispark device works however answers itselfs

I followed this guide to create an one wire bi-directional (debug) device for a Digispark (Attiny85): https://digistump.com/wiki/digispark/tutorials/debugging (see section Bi-directional Serial ...
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404 views

How to protect MCU IO and 5V from shorted +12V

I would like to protect an MCU from 12V being shorted either to IO or it's 5V supply. This is very similar to the question asked by kamil here: How to protect microcontroller board 1-wire from ...
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73 views

ADC reliability decreases as inputs connected

I'm using a 4-channel analog to digital converter, the TI ADS1115. I'm reading the values off the i2c bus with a Raspberry Pi. They worked ok for a few weeks- they read reliably about 95% of the ...
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268 views

64-bit Data Output On DHT21(AM2301) Sensor

I am trying to read the sensor data from the DHT21(AM2301) temperature and humidity sensor. According to the spec, the process of reading data is below: MCU sends start signal - Sensor sends ...
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59 views

Insulation when connecting a (TO-92) sensor with a cable

I'm considering using a DS18B20 which comes in a TO-92 package, but I have to place the sensor at a distance from the rest of the electronics so I'll have to use a wire to connect it. However due to ...
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1answer
392 views

I2C to 1-Wire@ 3.3v and 5v output transportation

I am feeding the I2C pins of a micro-controller into the converter shown in the circuit below to convert it to 1-wire protocol: However, the output will be at the level of 3.3 volts. I was ...
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2answers
141 views

Dallas/Maxim one wire initialization

I am using a Dallas DS18B20 thermometer that communicates with Maxim's one wire protocol. I'm having issues at the initialization sequence. I have pulled the line high for 500 uSeconds, pulled the ...
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2answers
525 views

Long range sensor readings in a star network with Arduino

I'm planning a project that requires me to have around a dozen temperature and humidity sensors placed around the house and the yard. These would connect to a central Arduino in the house that would ...
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1answer
138 views

ST L4 series datasheet specifications and 1 wire

When you open STM32L476 specification on the The DFSDM peripheral supports (42/232) it says that "Manchester coded 1 wire interface support". Does this means it supports 1-Wire bus like for DS18S20 or ...
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4answers
821 views

Using CAN bus tranceivers with custom data link layer

We needed a noise immune, low cost, multidrop, multi master (realtime and distributed) protocol and there is only CAN bus seems to meet with these requirements. Since there are no can controllers (...
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3answers
1k views

How to protect microcontroller board 1-wire from accidental +12V connection?

I'm working on modular LED strip driver with one "Master" board and up to 32 "Slave" boards. Each "Slave" board drives one LED strip. All boards have 3 pin terminals: - +12V (connected to 50W source) ...
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4answers
427 views

I have three DS18B20's. I can't tell if any of them are working correctly

I have three DS18B20's (or I believe at least two of them are DS18B20's). I am currently reading them through an embedded Linux board (Raspberry Pi in this case). I have two of the sensors in a ...
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1answer
225 views

1-wire : 4.7k resistor not working / how to compute optimal resistor topology for star layout

I've build a 1-wire network using a star topology (networking done trough my home's ethernet cables). At the begining I didn't own a 4.7k resistor but some 1.2k resistor so I lined them to achieve 1....
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2answers
989 views

How can I scan a One-Wire (1-Wire) bus for all connected devices and list their IDs

I have written a One-Wire (1-Wire, OW) controller in VHDL for FPGA designs. Currently I use a USB-OW adapter from Dallas/Maxim on my PC to get the sensors' IDs. I would like to scan the bus directly ...
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2answers
4k views

1-Wire DS2480B overvoltage and ESD protection

I'm designing a series of 1-Wire components for my SmartHome Bus and use the DS2480B as Busmaster. Because the cable I run around the house has 3 wires (24V, 1-Wire, GND), I'd like to protect the ...
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1answer
3k views

Pros / Cons of LM35 and Thermistor, what alternatives?

I'm wondering which benefits/downsides I have using following thermometer? Is there something I'm overseeing? For easy temperature measuring, what would be the easiest? My Opinion is LM35, am I right? ...
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1answer
2k views

1-wire bus topology using Cat5 cable

I have a 1-wire network using cat5 cable. There is a bus running along the roofspace of the building and the sensors are on stubs off this bus. The bus along the roofspace is about 25 metres long ...
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2answers
2k views

DS18B20 have the same 1-wire ids in proteus

I'm developing a temperature monitoring system and trying to model it in Proteus 8.1 SP1. When I try to execute rom search for multiple DS18B20 it give back just 1 ID, but if I add one DS1822 I can ...
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1answer
774 views

1-wire humidity sensor with ID

I've created a temperature monitoring system using multiple DS18B20 temperature sensors and now I want to add some humidity sensors to it. The problem is that I cant find any 1-wire humidity or ...
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1answer
442 views

Extending DS2408 IOs with MAX7219 or 74HC595

I have an idea of building a model traffic lights node with Arduino. One node should serve the whole intersection with all the lights from all directions. I want to use a 1-wire DS2408 to identify ...
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1answer
294 views

DS18B20 temperature interpretation

I have a problem interpretting the temperature reading of a DS18B20 chip. There is a certain situation I am not abble to resolve. This is the example temp table for the chip from the datasheet: an ...
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1answer
4k views

RS232 to 1-Wire interface - need help understanding the schematic

There are plenty of projects on RS232 to 1-Wire, each one of them is almost the same, but none of the sources really explain the wiring. Let's take this one: http://www.instructables.com/id/...
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1answer
115 views

onewire emulation in Software

Is there any full software implementation of onewire protocol ? I mean : can we have a SW that is manipulating a PIO to emulate fully the onewire protocol ? (for instance : ARM-M4 running @150MHz).
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177 views

DS18B20 temp sensor IC

DS18B20 temp sensor IC Dq pin is connected to PSEN of controller in my application. But in datasheet its mentioned that its ...
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1answer
1k views

1-Wire Serial communication to standard RX/TX Serial ports in microcontrollers

I just want to start by saying that I'm relatively new to electrical engineering in general, so if I sound absolutely retarded please bear with me. As part of a learning project I'm working with a ...
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1answer
4k views

Long distance Arduino sensor network - 1Wire protocol or RS422?

I have some sensors from each of which I need to - read a voltage - be able to switch them on. (They are powered by AC 220V power supply). Distance to be covered is some 40 meters. I don't want to ...
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1answer
607 views

Max voltage output of DS18B20

I am using the DigiX board and trying to connect a DS18B20 (one wire temperature sensor). One of the issues with the DigiX is that it can only tolerate 3.3V on the I/O pins. I have been trying to ...
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0answers
603 views

Connect sensor to 1-wire dual counter - different power sources

I am much more comfortable in software than hardware, but I'm working on a home automation project to track water usage. I have a Dinel AFP-966-S fiber optic sensor positioned over the water meter - ...
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2answers
5k views

What is the standard 1-wire bus connector?

What is the normal connector that people put at the end of a long cable with a MAX31820 / DS18B20 temperature sensor at the other end? What is the normal connector that people solder to the PCB when ...
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1answer
125 views

Identify iButton location

A friend asked me for advice regarding a lock system based on iButtons as keys. There are some doors, and a 1-wire bus along the way, connected to iButton readers and door locks. (let's skip the ...
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2answers
691 views

What happens if I accidentally connect an Ethernet device to my 1-wire bus?

I have built a networked temperature sensor by connecting several DS18B20 temperature sensors to my Arduino. I've tried to visualize the setup with this schematic (sorry if this doesn't make any sense,...
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1answer
2k views

Read DS2401 with ATmega 32 and a 1-Wire protocol

DS2401 is a 64-bit ROM memory that used as a hardware-serial-number. [Datasheet : here] It has only two pin. One of them is ground and one of them is Data/Power pin. So for communicate with this chip ...