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Questions tagged [smbus]

The tag has no usage guidance.

0
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0answers
11 views

Laptop battery smbus broadcasting

I connected a laptop battery connector to a micro-controller through SMBUS. I can read information from battery such as state of charge. I listen to the battery broadcasting charging current and ...
0
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1answer
67 views

Disadvantage of using low resistor value for pull up (Strong pull up)

I was trying to choose a resistor value for a pull-up resistor I will use in my project. The project will have I2C communication and SMBus communication. When I was searching on the internet, I have ...
1
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2answers
70 views

SMBus pull-up resistor value

Hello I need to communicate with a device using SMBus. However, I could not choose correct value for pull up resistors. Vdd is 4.9V and I use SMBus. In same conditions for I2C communications I used 2k ...
1
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0answers
32 views

SMBus Read Word Protocol

I want to communicate with a device that is using SMBus. I use PIC18F26K83. I am inexperienced but before that I implemented I2C communication. In I2C communication, what I do in order to write to ...
0
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1answer
49 views

PIC I2C Clock selection

Hello I will be communicating with a device using SMBus. For this, I will be using PIC18F26K83. Timing is not important for me so I m somehow free to choose any clock frequency for my MCU. Well higher,...
5
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1answer
1k views

IC has pull-down resistors on SMBus lines?

The datasheet of TI bq40z50-R2 (Li-Ion Battery Pack Manager) tells that "The SMBus clock and data lines have internal pulldown". Pin equivalent Diagram is in image below: Aren't usually the SMBus ...
0
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1answer
45 views

PIC I2C PPS mapping

I will be communicating with some device via SMBus. I use PIC18F26K83 and I will use RB1 and RB2 pins as SCL and SDA pins. My question is about PPS mapping. In datasheet it says that I need to set ...
0
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1answer
74 views

SMBus: Is 100 kHz clock a risky frequency?

I will communicate with a device via SMBus. I use PIC18F26K83 for this. In SMBus spec it says clock minimum clock frequency is 10 kHz and maximum clock frequency is 100 kHz. Would it be a risk to use ...
0
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1answer
25 views

SMBus v1.1 voltage threshhold value

I am planning to use PIC18F26K83 and communicate with a smart battery that uses SMBus ver 1.1. So from the datasheet of PIC it says I need to choose appropriate input threshhold for SMBus from RxyI2C ...
0
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0answers
28 views

SMBus Address and BaudRate

Hello I need to communicate with some batteries ( BT-70791CK from BrenTronics). They use SMBus ver 1.1 for communication, but in datasheet of the batteries there is no information about the SMBus ...
0
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1answer
35 views

SMBus default Baudrate and Address

I am trying to communicate with some batteries that uses SMBus. In the documens of batteries it only specifies the SMBus version which is SMBus v1.1 and do not mention about addresses nor the baudrate ...
0
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1answer
101 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
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3answers
165 views

How should I used two MLX90614 sensor on one Arudino Uno given that the sensor has a fixed I2C bus adress? [duplicate]

I have an arduino uno and want to use a non MLX90614. I plan to used more than one sensor on the same Arduino but I don't know how to use two MLX90614 on the same I2C bus.
0
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4answers
188 views

STM32F103C8T6 - I2C communication with TI FuelGauge BQ78350

I am trying to establish communication between TI BQ78350 FuelGauge and STM32F103C8T6 using I2C/SMBus. The following is the I2C configuration used for the standard HAL I2C library. ...
1
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1answer
52 views

How does integrated displays controlled by the computer?

Consider a run off the mill pc: lcd displays connected, you have brightness control in the menu of the lcd. And some other stuff like color temp and modes. Now consider a laptop, AIOs and kiosk PCs. ...
1
vote
1answer
141 views

LTC4015 variable i2c speed operation

I am planning to use LTC4015 IC for buck charger application . I have to interface the IC with my host MCU. LTC4015 PRODUCT PAGE I have other charge controlller ICs connected over same I2C bus. ...
1
vote
1answer
725 views

What are the various ways in which an I2C bus may hang

I am very new to electronics and have entered in the territory of I2C bus. Want to understand the behaviour of compliant devices as per I2C protocol specification. One condition as per the link below ...
1
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1answer
170 views

Bus isolation circuit

I got a question about BUS isolation circuits. Is this a correct design? Looks not to me. The book said that if POWOK is high, two SMBUS will connect together. But I think it's wrong, the NMOS should ...
1
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1answer
256 views

Is this chip 0.5mm pin pitch?

Am I correct in thinking that this chip has 0.5mm pin pitch? I don't know where to look for it on the details of the chip! When I google for '144-LQFP' I found a link which suggests it is 0.5mm pitch ...
1
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1answer
291 views

Compatibility between I2C and SMBus

I am looking to interface a Melexis IR sensor to a AVR micro(ATmega2560). The sensor has an SMBus interface. The datasheet of the micro does not explicitly state that it supports SMBus. But it has a ...
1
vote
1answer
100 views

How to set NACK on bad PEC in TWI used for SMBUS (ATMega8) [duplicate]

I want to implement the SMBUS protocol in my AVR device (ATMega1284P), which will have the role of slave. I need to support the PEC (Packet Error Code) feature, which means that the master device (...
3
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2answers
545 views

Possibility of SMBus/PMBus device with I2C Master?

Can I communicate with a SMBus/PMBus device with I2C? I've been reading the specs and getting quite confused. It seems to me the only difference is the voltage levels and the need to have a restart ...
2
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1answer
363 views

Problem I2C NACK in 3rd byte MLX90614 - Repeated Start

I am trying to read Melexis MLX90614 infrared temperature sensor through SMBus (I2C or TWK like protocol). The protocol (SMBus) implement an special type of command or sequence called repeated start, ...
6
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2answers
3k views

Is there a standard I2C/SM bus protocol for laptop battery packs

I'm undertaking the challenge of building a custom laptop, with a custom battery pack, I know that the battery pack has to communicate over an I2C/SM port on the motherboard, but I don't know how to ...
1
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1answer
461 views

I2C slave compatible with SMBus protocol?

I do have some inquiries regarding using an I2C slave controller (from Arria 10 FPGA). We are currently assessing MCTP protocol support in our device, whose physical layer is built upon SMBus/I2C, ...
0
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2answers
74 views

What is the host in this schematic?

In this schematic it shows the smbus as a separate unit, what im wanting to know is this a seperate ic that i have to integrate in or is it just simple as a usb port? image http://www.ti.com/ods/...
0
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2answers
634 views

MLX90616 Infra Red Temperature Sensor problem

Recently I have been trying to interface with the MLX90616 an infra red temperature sensor by Melexis. After reading the datasheet I have I have written a program to take the object temperature ...
1
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2answers
88 views

Using on chip I2C on NXP P89LPC954

I am trying to use on chip I2C on NXP P89LPC954 microcontroller(80C51 based) for voltage monitoring. I have two voltage monitoring chips of same kind(same chip with same register address) connected ...
0
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1answer
102 views

Does SMBus spec lie about I2C?

In the SMBus spec it says: The I²C specifications do not require that a device always acknowledge its own address. This can confuse a system controller. If a device does not acknowledge its own ...
1
vote
2answers
1k views

PS2 / SMBus communication

I have an OEM touchpad I want to connect to a PC. The drivers for this touchpad are widely available. I asked the manufacturer for the original datasheet, and it says there, that the touchpad ...
1
vote
1answer
408 views

SMBus using Silicon Labs C8051F560

I am trying to communicate an arduino with a Silabs F560 Toolstick Daughter Card. On Arduino (Master) I have loaded the i2c scanner program from http://playground.arduino.cc/Main/I2cScanner which ...
0
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1answer
407 views

How does SMBus receive byte command protocol know what to send?

Im programming an I2C device to act as a PMBus slave. Looking at the SMBus protocols (which PMBus is built on) the Receive Byte command has a format described as follows: ...
2
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2answers
1k views

My CRC8 is dysfunctional and I'm not sure why!

So I'm interfacing an arduino with a Melexis temperature sensor, and it's going okay--aside from the fact that I can't seem to get the CRC check to work. I've gotten read operations to complete ...
8
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1answer
4k views

Is it possible to only utilise SMBus on PCI Express 1X?

According to the Wikipedia page on PCI Express, the PCI-e 1X slots have 18 pin positions on two lanes (so 36 pins) and positions 5-9 represent SMBus and JTAG. I'd like to hook up a µC as an ...
1
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0answers
1k views

Raspberry Pi with SMBus SmartBattery

I'm trying to interface a Raspberry Pi with the mini-box OpenUPS. It claims to implement the Smart Battery SMBus specifications. I can read data from the device using the i2c_smbus_read_word_data() ...
0
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2answers
763 views

Dev Platform to talk to PMBus/SMBus/I²C Power Supplies

I am looking for a simple way to talk to PMBus power supplies (ie. get current information, turn power supply on or off, etc). This is normally integrated on computer main boards or server main boards....
2
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2answers
4k views

SMBus with AVR?

I'm looking at using some sensors that have an SMBus interface. The signaling looks an awful lot like I2C. What are the main differences between I2C and SMBus? Can the TWI hardware of an AVR talk to ...
8
votes
2answers
2k views

Is there only one SMBus on PC Motherboards?

I have connected two wires to the SMBus clock and data lines of my motherboard (manually soldered via wires, because there is no header). I wish to interface this bus to my microcontroller. I hooked ...