All Questions
49
questions
0
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0
answers
27
views
Which ATtiny TWI parameter provides more robust operation?
I'm using an ATtiny3226 as an I2C client (slave) interface in a robot, to get commands from the main controller (single master) using I2C on a shielded cable.
There are brushless and servo motors ...
- 2,017
1
vote
0
answers
689
views
Bit-bang I2C implement on DS1307 and Atmega328P problem
I currently implement I2C bit-bang for Master Arduino (AVR) to Read/Write to Arduino Slave using Wire.h and DS1307 RTC. My bit-bang i2c work perfectly with Arduino Slave read 8 bytes without ...
- 33
1
vote
1
answer
203
views
Missing 1 bit shift Bitbang I2C Atmega328p
I implement bit-banging I2C on Atmega328P and met the problem when the Master receives data from the slave. I'm in depression in debugging this code since I found no problem. Master Write work ...
- 33
0
votes
0
answers
36
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APDS-9253 reads all data registers as 0
I'm trying to read data from an APDS-9253 with an xmega.
My i2c bus is working because I'm reading other devices without any problem.
From the datasheet it seems at power-up the sensor is not ...
- 1,235
0
votes
1
answer
303
views
I2C Communication in AVR
The first step in a TWI transmission is to transmit a START condition. This is done by
writing a specific value into TWCR, instructing the TWI hardware to transmit a START
condition. Which value to ...
- 1,079
0
votes
3
answers
112
views
I2C clarification
This question is mainly to check if I understood i2c protocol and hardware correctly. Because pin modes confusing me a little, ia m jsut a beginner.
I2C SDA and SCL lines are pulled high with pull up ...
0
votes
2
answers
222
views
Can I use one pin as I2C clock or data AND as GPIO?
It happened to be that I run out of pins on ATmega48PA. So I have a pull-down buttons on the pins dedicated for I2C:
And now I need to add I2C bus to this device with as much backward compatibility ...
- 3,012
0
votes
1
answer
1k
views
AVR Can Write I2C, but Fails to Read (Fails to Write Register Address)
I'm using an ATMega328 DIP Package with a TLE493D(A0) (and manual) 3-axis hall effect sensor. I've done successful reads/writes to other I2C devices (AT42QT2120), but I'm having issues with the TLE493....
- 400
0
votes
0
answers
32
views
Arduino I2C bus fails when one slave is powered down [duplicate]
I have a set of Arduino Nano units where one is I2C master broadcasting messages to a number of slaves. It works perfectly fine when they are all powered on.
The Arduino units are all interconnected ...
- 101
1
vote
3
answers
1k
views
SSD1306 I2C: Draw only changes works however on wrong position, how to set position (command)?
I create an OLED display class for the SSD1306 and how it works is pretty straight forward. The display is buffered (offscreen method) and at performing an update, it 'dumps' the buffer to the display ...
- 1,367
0
votes
1
answer
2k
views
I2C communication ATmega328P slave: answer to general call but not to own address
I have the following problem:
I want to make two AVR Atmega 328P-Pu communicating together with I2C
No1 is Master (I2C address :0x01)
No2 is Slave (I2C address :0x02)
On slave answer to general ...
1
vote
0
answers
675
views
Reuse I2C SCL or SDA Pins to signal interrupt
In an I2C network, I am using an AVR microcontroller (AtMega328p) as a Master and I hooked it up to multiple sensors as Slaves, such as the TMP102, SI1145, MPU9250, among others.
All of these sensors ...
- 155
0
votes
2
answers
239
views
AVR ATmega TWI Hardware Questions
I have thoroughly read the TWI part of ATmega data sheets, but I am still confused about a few things.
If I write TWCR = (1 << TWINT);, will that write a ...
- 688
1
vote
1
answer
233
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 (...
- 907
-1
votes
2
answers
374
views
I2C communication problems unless test equipment is attached
I have a RaspberryPi acting as a master for an Atmel ATTiny861A slave over I2C, continuously sending a command plus 3 bytes of data to light an RGB LED. This works perfectly but only if the AVR ...
