Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [smbus]

System Management Bus (SMBus or SMB for short) is a single-ended two-wire bus derived from I2C.

System Management Bus (SMBus or SMB for short) is a single-ended two-wire bus derived from I²C.

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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 SMBus (essentially I²C) device, and I understand the…
Polynomial
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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 these up to my scope, and they show the correct…
cksa361
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Is there a standard I2C/SM bus protocol for laptop battery packs

I'm building a laptop with a custom battery pack. I know that the pack has to communicate through an I2C/SM port on the motherboard, but I don't know how to make the bios/os recognize it. Is there a particular I2C address and standard protocol on…
user51404
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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 Data and Clock lines to be connected to pull-up…
haku15
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How to convert SMBUS example code to fully compatible MCU, STM32L4R5 -> STM32L496

Has anyone been able to use the STM32 SMBUS/PMBUS examples codes, and successfully port it to another compatible mcu? If so what was the steps taken for the conversion? (Currently trying to flash STM32L4R5- Nuleo SMBUS example code onto the…
soccernismo
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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 successfully (although my software ignores the packet…
Noah
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How can I understand the bytes of sensor memory without having the memory map in I2C bus

I am a data scientist and I do not know much about programming and electronics. However, I have to get some data from an O2 sensor. The sensor (Gravity O2 Sensor 0-25%) is a cheap Chinese one (~ 60 Euros) Unfortunately, the library that the…
Leo
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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 SMBus peripherals? If the answer is "it depends"…
vicatcu
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How to calculate the Samples per second possible of a ADC (MAXIM 11605) using i2c with raspberry pi?

I would like to find out how many samples per second this ADC im using is capable of with a raspberry pi using i2c and python SMBUS2 library, but i dont know where to start. As far as i know this depends on: CPU speed (how fast python runs), i2c…
BetweenBeltSizes95
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Why does each device have two SMBus addresses?

I am working on PMM240 (a power management board for RRC battery) with RRC2054-2 battery. First when I only connect PMM240, the manual has address 0x20, but when I scan the port, I have two addresses, 0x20 and 0x21. If I connect the battery, in…
adam
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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 condition. Am I correct or I'm missing something?
flashburn
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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, that means we send a start condition without a…
mapedraza
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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() function as defined in the Linux Kernel docs. So,…
Mark Baldridge
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STM32G0 Stuck on SMBUS Slave

This question has been "self answered". Please see answer below. I am trying to communicate with SMBUS Master and Slave configuration on both STM32G070RB (NUCLEO Boards). So the master sends the address signal correctly to the slave. I can see the…
devscg
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Detect power/run status of PC in hardware

This may well be a daft question and/or a failure to google effectively (and apologies if this would be a better fit on SuperUser or somewhere else?) but is it possible, in low-level hardware, to detect the "run" status (possibly ACPI state) of a…
John U
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