Questions tagged [smbus]
System Management Bus (SMBus or SMB for short) is a single-ended two-wire bus derived from I2C.
60
questions
0
votes
0
answers
92
views
I keep Blowing up my i2C (ISO1540) isolator when plugging and unplugging my battery
I am using a ISO1540 to read the SMBus of some BB2590 batteries. The relevant part of the circuit is shown in the images below
The issue that I am having is that sometimes when connecting or ...
- 1
0
votes
2
answers
227
views
FT232H: Clock stretching using MPSSE
I use an AN108 to drive my I2C line (actually SMBus).
I'm debugging with an oscilloscope.
Doing a read, right after the 8b address, I found that the slave was pulling down my clock signal SDC for a ...
- 347
2
votes
2
answers
179
views
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 ...
- 51
3
votes
0
answers
15
views
How to convert SMBUS example code to fully compatible MCU, STM32L4R5 -> STM32L496 [duplicate]
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 ...
- 57
0
votes
1
answer
84
views
STM32 - Porting/Tailoring Example Files to different Microcontroller - xcubeide
How do you convert a project made for one development board for another development board within X-CUBE-IDE.
I am trying to copy a SMBUS example over to a different Development board, so I was ...
- 57
1
vote
1
answer
207
views
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 ...
- 108
0
votes
1
answer
79
views
What is the "Smart Battery Connector" for 9V rechargeable batteries?
I'm looking for a battery charger for 9V rechargeable batteries (must be switch-mode, not linear).
I came across the "Smart Battery Standard Connector" structure in a controller IC datasheet ...
- 21
1
vote
0
answers
70
views
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 ...
- 7,041
0
votes
2
answers
269
views
Slow read from IST8308 via I2C using Python and smbus2
I have an Arm64 Linux board and an IST8308 3D magnetometer that I am reading via I2C with the following script:
...
- 103
1
vote
2
answers
838
views
Multiple PCIe devices in a single M.2 slot
I have a M.2 M-keyed slot on my laptop, and multiple M.2 PCI-e devices that I'd like to use at the same time. I've been looking for a M.2 switch or splitter of sorts but couldn't find anything, so I ...
- 373
0
votes
0
answers
896
views
SMBus ARP working example
I've been playing around with an arduino and a few sensors when I came across this amazing communication protocol I2C with which a master can communicate with all of the sensors (or slaves in a more ...
- 141
1
vote
0
answers
145
views
SMBUS on STM32F091
Any example code available to implement smbus(master and slave) interrupt mode on stm32f091rc ? Tried using the HAL functions was not successful?
In Master mode to transmit I use
while(1)
{
while(...
- 11
0
votes
1
answer
87
views
Writing to BQ25700A with i2c_smbus_write_block_data
I'm trying to write to a TI buck boost charger (BQ25700A) using the i2c_smbus_write_block_data command, to try to provide current to a battery.
...
- 101
0
votes
0
answers
472
views
No voltage at battery terminals
I replaced the cells on my Laptop unfortunately disconnected BMS while doing so.
HP battery check says each cell voltage and Temp correctly and calibration warning but can't calibrate as no terminal ...
2
votes
0
answers
308
views
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 ...
-1
votes
2
answers
490
views
Why are VOL and IOL seperately defined in I2C and SMBUS?
What is the point of defining VOL and IOL separately in I2C and SMBUS?
0
votes
1
answer
47
views
What kind of application forces SMBus to specify a "TIMEOUT" that keeps the minimum frequency to 10Khz?
Why "TIMEOUT" has been defined in SMBus that forces the minimum frequency to be 10kHz?
Please tell a solid industrial application.
0
votes
2
answers
102
views
What is the maximum capacitance allowed on SMBus? Why was the VIL fixed to a maximum of 0.8V?
How to interpret the significance of DC specification in SMBus?
Why is the VIH value has been fixed to a minimum of 2.1V?
0
votes
1
answer
355
views
STM32 trying to communicate with two I2C, but the second one fails
I am trying to communicate with a battery using SMBUS. The battery has 2 sections so it uses 2 separate SMBUS lines. I am trying to read SOC information from the two section using an STM32F103C8.
The ...
0
votes
1
answer
650
views
STM32 I2C transmitting no data and cannot change the data that is being transmitted
I am trying to establish a SMBus connection by using STM32 chip. When I try to transmit data to battery (0x0D) I see 0x0B with oscilloscope. When I change the data that is being transmitted to 0x00 or ...
0
votes
1
answer
223
views
how to understand SMBus SDA line captured waveform
I am using MCU (L476RG) with PMM240 (power management board) and RRC 2054-2(battery), I am figuring out why SMBus is always busy after sending command to slave, so I captured the waveform when I send ...
- 49
2
votes
2
answers
249
views
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,...
- 49
1
vote
1
answer
1k
views
SMBus is always busy after HAL_SMBUS_Master_Transmit_IT()
I'm using PMM240 power management board to control battery RRC-2054, and I have problem to use SMBus, please see the code I listed below, looks device is ready, but when you send something, it is ...
- 49
1
vote
1
answer
275
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
vote
2
answers
2k
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
vote
0
answers
743
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
votes
1
answer
245
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
votes
1
answer
2k
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 ...
- 323
0
votes
1
answer
508
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
votes
1
answer
460
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
votes
1
answer
79
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
votes
0
answers
285
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
votes
1
answer
157
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
votes
1
answer
573
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
3
answers
400
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.
- 1
0
votes
4
answers
1k
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
vote
1
answer
78
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. ...
- 199
1
vote
1
answer
386
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 controller ICs connected over same I2C bus. Other ...
- 133
1
vote
1
answer
3k
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 ...
- 111
1
vote
1
answer
482
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 ...
- 601
1
vote
1
answer
327
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 ...
- 444
1
vote
1
answer
490
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 ...
- 323
1
vote
1
answer
214
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 (...
- 897
2
votes
2
answers
1k
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 ...
- 287
2
votes
1
answer
797
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, ...
- 21
7
votes
2
answers
6k
views
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 ...
user51404
1
vote
1
answer
784
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, ...
- 111
0
votes
2
answers
130
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?
(source: www.ti.com)
0
votes
2
answers
928
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 ...
- 901
1
vote
2
answers
106
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 ...
- 31