I2C noise into the audio signals

Started by Anonymous in sci.electronics.design4 years ago 19 replies

We have TDA7719 audio processor and OLED display connected to the same I2C = bus as I2C slaves. Both the devices are driven by MCU which is I2C...

We have TDA7719 audio processor and OLED display connected to the same I2C = bus as I2C slaves. Both the devices are driven by MCU which is I2C master. = After TDA7719 is initialized with I2C for input selection and volume, it st= arts working. The MCU keeps refreshing the display by continuously writing = data to the display through the same I2C bus. This I2C noise is getting cou= pled into ...


I2C Level Translator

Started by Tim Wescott in sci.electronics.design1 year ago 19 replies
I2C

So, I was happily working away, designing in a 2.5V part to talk to the I2C bus from a 5V processor, when reality caught up to me. 2.5V. 5V....

So, I was happily working away, designing in a 2.5V part to talk to the I2C bus from a 5V processor, when reality caught up to me. 2.5V. 5V. I2C. It appears that NXP has some I2C level translators -- does anyone have any mileage with them? Do they work? Anyone have any parts to either embrace or avoid? I can certainly see some issues with trying to make it all reliable, and back...


Painless I2C reading

Started by Phil Hobbs in sci.electronics.design6 years ago 45 replies
I2C

Hi, all, For a patent infringement case, I need to dump the contents of a small I2C EEPROM (an Atmel AT24C01A). I've actually never used an...

Hi, all, For a patent infringement case, I need to dump the contents of a small I2C EEPROM (an Atmel AT24C01A). I've actually never used an I2C part--I sort of standardized on SPI at an early age and never deviated, mostly because I never needed multi-master and had heard evil things about I2C reliability. So I have zilch equipment to do this. Does anyone have a painless way to do ...


I2C to PWM IC

Started by Michael in sci.electronics.design2 years ago 17 replies

Does anybody make an IC that takes I2C command and outputs duty cycle (PWM)? I need to control bunch of TECs from CPU and I2C-> PWM seems the...

Does anybody make an IC that takes I2C command and outputs duty cycle (PWM)? I need to control bunch of TECs from CPU and I2C-> PWM seems the most efficient (and smallest) way to do it. Any suggestion will be appreciated. Thanks Michael


I2C switch/multiplex

Started by Mikko OH2HVJ in sci.electronics.design9 months ago 2 replies

I've got a task of cramming in a GPS receiver with I2C interface to an existing small board. The receiver is rather power hungry (50uA) even in...

I've got a task of cramming in a GPS receiver with I2C interface to an existing small board. The receiver is rather power hungry (50uA) even in sleep mode compared to the target of 3uA at 2.8V. I was planning on isolating the GPS receiver from the system with a P-fet in the power line and analog dual switch on the I2C lines. These being controlled PCA9570 or similar I2C GPIO extender. Al...


PIC question

Started by Anonymous in sci.electronics.design9 years ago 17 replies
I2C

I am tired of writing bit-banger I2C pseudo-masters, so I looked for PICs with I2C masters built-in. There seem to be very few. Do they have to...

I am tired of writing bit-banger I2C pseudo-masters, so I looked for PICs with I2C masters built-in. There seem to be very few. Do they have to pay a license fee to someone to include a I2C master? Or does it use a lot of silicon real estate? Or is it generally that PICs are used in slave devices?


I2C over long bus

Started by Jon Slaughter in sci.electronics.design9 years ago 12 replies

Anyone here familiar with using I2C over a long bus, say up to a few hundred feet? Basically either using charge pumps and/or slower speeds(even...

Anyone here familiar with using I2C over a long bus, say up to a few hundred feet? Basically either using charge pumps and/or slower speeds(even < 1k will work). I know there are some driver chips(but quite expensive for what they do) and I'm curious as to if there are any simple solutions. (basically connecting an I2C temp sensor(or several) over about 200 feet to a uC. That or I wa


I2C master

Started by David Lesher in sci.electronics.design14 hours ago 27 replies

In theory, I2C handles multiple masters. Wonder if anyone is doing so, and if so, how hard was it to get up & running? -- A host is a...

In theory, I2C handles multiple masters. Wonder if anyone is doing so, and if so, how hard was it to get up & running? -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy, hung or dead..


How about it? Experiments of the third kind , take 999999.

Started by Jan Panteltje in sci.electronics.design5 years ago 32 replies

Design changes: Acquisition data will be stored in a 24LC256 i2c serial EEPROM (on order). I ran out of enough code space in the 18F14K22 to...

Design changes: Acquisition data will be stored in a 24LC256 i2c serial EEPROM (on order). I ran out of enough code space in the 18F14K22 to store 8760 x 2 bytes (24 hours x 365 days), as I have a lot of extra test stuff added. Now I have 32 kB. As the 18F14K22 SPI is broken, and the i2c uses the same hardware, I wrote i2c software today to write and verify the data, just in case. I rep...


DAC with GPIO?

Started by Anonymous in sci.electronics.design8 years ago 2 replies

Just an idle thought. A serial I2C DAC with a 6 pin package needs gnd,vcc,sda,scl,out. If you can select the I2C address as a variant of a base...

Just an idle thought. A serial I2C DAC with a 6 pin package needs gnd,vcc,sda,scl,out. If you can select the I2C address as a variant of a base part number, that leaves one free pin... I'd like that pin to be a GPIO, or just a digital out. I'd like to control the ENA pin of an OCXO with the same I2C bus as the DAC. Is there such a beast, and if not, why not! Maybe a 6 or 8 pin uC programme...


PIC daughterboard detection

Started by Randy Day in sci.electronics.design2 years ago 8 replies
I2C

I'm wanting to have a PIC detect whether a daughterboard is present, so it can activate I2C comm. My thought is to activate the weak...

I'm wanting to have a PIC detect whether a daughterboard is present, so it can activate I2C comm. My thought is to activate the weak pull-down on the input, to detect whether an I2C pull-up resistor (10k) is present on the line, before turning on I2C. Is this an acceptable use of the weak pull-down features of the PIC? I'm a bit unclear on the do's and don'ts of WPU/WPD. (terr...


Muxing I2C question

Started by Mook Johnson in sci.electronics.design3 years ago 2 replies
I2C

I have an application where I have 8 identical I2C devices that I cannot change the address on. I need to talk to all 8 in sequence and...

I have an application where I have 8 identical I2C devices that I cannot change the address on. I need to talk to all 8 in sequence and considering a 1:8 MUX. I'm pondering if I need to MUX both the SCL and SDA lines. If I mux only the SCL line so only the one I'm talking to sees the clock, but all of them see the activity on SDA would the device care. I wouldn't think so becau...


I2C bus needs capacitance?

Started by DemonicTubes in sci.electronics.design11 months ago 43 replies

I've got a couple boards that use this method to level shift: http://imgur.com/a/yjD58 The I2C master is 3.3V while all the slaves are 5V...

I've got a couple boards that use this method to level shift: http://imgur.com/a/yjD58 The I2C master is 3.3V while all the slaves are 5V devices. This works fine, except on the newest board. Only one of the (3 in this case) slaves respond. Scoping the wave-forms and comparing with another board with the same circuit (different PCB layout, however) shows they are identical...until


I2C bus.

Started by Anonymous in sci.electronics.design8 years ago 3 replies
I2C

This is a multi-part message in MIME format. ------=_NextPart_000_0158_01C9CD7B.0BA60170 Content-Type:...

This is a multi-part message in MIME format. ------=_NextPart_000_0158_01C9CD7B.0BA60170 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable http://standardics.nxp.com/literature/books/i2c/pdf/i2c.bus.specification= .pdf Bob ------=_NextPart_000_0158_01C9CD7B.0BA60170 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding...


Output boards, SPI vs I2C

Started by David Lesher in sci.electronics.design6 months ago 25 replies

I pondering a microcontroller project that will need a number (say 24) output relays. Is there a reason to use I2C over SPI? It looks like...

I pondering a microcontroller project that will need a number (say 24) output relays. Is there a reason to use I2C over SPI? It looks like there are 8-channel boards of both ilks, and I don't know if one has an advantage in this case. -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the hos...


Wow 460800 Bd via USB to serial adaptor works!

Started by Jan Panteltje in sci.electronics.design5 years ago 1 reply

Wow 460800 Bd via USB to serial adaptor works! Wanted to add a par port to my laptop, or at least some I/O pins. At 460800 Bd you can send a...

Wow 460800 Bd via USB to serial adaptor works! Wanted to add a par port to my laptop, or at least some I/O pins. At 460800 Bd you can send a byte in 2.17 uS. That means if I want to test I2C chips via USB to RS232 adaptor, and use only one state flip per bit, something that requires 4 bytes RS232 per I2C bit processing, for example: SDA high SCL high SCL low SDA low makes 10.8 ...


microcontroller

Started by michealFan scofield in sci.electronics.design7 years ago 2 replies
I2C

hello, i am new here. can someone help me for the folowing query?: i want to save value of timer to eeprom, do i have to use I2C...

hello, i am new here. can someone help me for the folowing query?: i want to save value of timer to eeprom, do i have to use I2C module? thanks in advance stephanie


Is it me, or...

Started by Anonymous in sci.electronics.design9 years ago 1 reply
I2C

There are more and more chips out there with three and four level digital input pins? Like the AD9514 for example. Seems like a good trend,...

There are more and more chips out there with three and four level digital input pins? Like the AD9514 for example. Seems like a good trend, keeps the packages smaller, but then why not just add a SPI or I2C interface?


connecting 2 keypads on rsp

Started by gm in sci.electronics.design10 months ago 6 replies

Hi to all. Because of the amount of the system users ( cca 500 of them ) i need to setup some 4x5 or 4x6 keypad. To do so am planning to use...

Hi to all. Because of the amount of the system users ( cca 500 of them ) i need to setup some 4x5 or 4x6 keypad. To do so am planning to use some standard 4x4 + one 2x4 keypad over i2c. Should this be problem to construct in the way that the second keypad is recognized as extension of the first one ? So 1-16 --- 17-24 GM


Sigma delta audio dacs

Started by bitrex in sci.electronics.design2 years ago 13 replies
I2C

I'd like to drive 6 channels of 16 bit, 44.1 kHz audio out of an ARM Cortex M4 processor, using i2c I guess. There are so many DACS out...

I'd like to drive 6 channels of 16 bit, 44.1 kHz audio out of an ARM Cortex M4 processor, using i2c I guess. There are so many DACS out there...so this is another one of those "so what is cheap and worked good for you" kind of questions. -- ----Android NewsGroup Reader---- http://usenet.sinaapp.com/