Problem with multiple I2C devices in a bus...
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From: starfire on 19 Feb 2005 14:27 "Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message news:20050219.1527.306859snz(a)pcserv.demon.co.uk... > On Friday, in article <111cuurpm51bce5(a)corp.supernews.com> > starfire151(a)cableone.net "starfire" wrote: > As others have said please reply at the BOTTOM it is getting tiring > re jigging your posts.. >>"Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message >>news:20050218.0921.306810snz(a)pcserv.demon.co.uk... >>> On Thursday, in article <11195fvbv8h9l33(a)corp.supernews.com> >>> starfire151(a)cableone.net "starfire" wrote: >>>>"Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message >>>>news:20050217.0937.306771snz(a)pcserv.demon.co.uk... >>>>> On Wednesday, in article >>>>> <1117u2aiovrobdc(a)corp.supernews.com> >>>>> starfire151(a)cableone.net "starfire" wrote: >>>>>>Hi all - >>>>>> >>>>>>Has anyone had any experience with using multiple I2C devices is a bus >>>>>>architecture? ....snip... > In my application EEPROM was no use as the power unit had to reset, and a > startup sequence was needed, a saved value would set the wrong mode and > smoke. > Without looking too hard I know that Dallas (now Maxim) and Xicor (now > Intersil) do parts with EEPROM. > > A google search for "+EEPROM =pot" or "E2Pot" will turn up a lot of > results. > > The fact that Dallas/Maxim do parts with EEPROM and you had not found that > out worries me to how well you are looking at the problem as myself and > others > have pointed out several items to check. > > -- > Paul Carpenter | paul(a)pcserviceselectronics.co.uk > <http://www.pcserviceselectronics.co.uk/> PC Services > <http://www.gnuh8.org.uk/> GNU H8 & mailing list info > <http://www.badweb.org.uk/> For those web sites you hate Paul - Thanks for the resposne, again. I have been trying everything that everyone has suggested to check. That's how I ultimately found the answer (due to the no ack on the last read) to the problem. I have checked Dallas/Maxim and Xicor for EEPROM pot parts but they don't make such parts with multiple addresses, dual devices, EEPROM, and I2C in an SOIC package, as was my original request. I have also checked into the Xicor parts. Ditto. I have, in fact, done complete parametric searches on the Dallas/Maxim, Microchip, and Xicor sites. The closest I've found is the Maxim MAX5479, which is in a different package style. I'm putting my circuits together by hand (without using reflow ovens, etc.) so my package styles are necessarily somewhat limited. I can't do ball grid arrays, for instance. Thanks for the help. Dave
From: Paul Carpenter on 19 Feb 2005 19:55 On Saturday, in article <111f4oihcoli210(a)corp.supernews.com> starfire151(a)cableone.net "starfire" wrote: ..... >> In my application EEPROM was no use as the power unit had to reset, and a >> startup sequence was needed, a saved value would set the wrong mode and >> smoke. >> Without looking too hard I know that Dallas (now Maxim) and Xicor (now >> Intersil) do parts with EEPROM. >> >> A google search for "+EEPROM =pot" or "E2Pot" will turn up a lot of >> results. >> >> The fact that Dallas/Maxim do parts with EEPROM and you had not found that >> out worries me to how well you are looking at the problem as myself and >> others >> have pointed out several items to check. >> >Paul - > >Thanks for the resposne, again. .... >I have checked Dallas/Maxim and Xicor for EEPROM pot parts but they don't >make such parts with multiple addresses, dual devices, EEPROM, and I2C in an >SOIC package, as was my original request. I have also checked into the >Xicor parts. Ditto. But it depends on what you mean by SOIC, as there are 150mil and 300mil variants. Most 14-20 pin TSSOP (173mil) packages are similar to SOIC 150mil. >I have, in fact, done complete parametric searches on the Dallas/Maxim, >Microchip, and Xicor sites. >The closest I've found is the Maxim MAX5479, which is in a different package The package style is close enough to the SOIC 150ml (if not slightly larger) Actually the DS1803 is also available in 14pin TSSOP >style. I'm putting my circuits together by hand (without using reflow >ovens, etc.) so my package styles are necessarily somewhat limited. I can't >do ball grid arrays, for instance. I do lots of boards by hand with SOT23-5 and even 144pin TQFP on 0.4mm pitch. The TSSOP is slightly larger so probably easier to hand solder, also the pin out probably makes isolation between load and micro easier. You just have to be careful and an iron which can go don to 0.2mm tip helps on reworking as well. -- Paul Carpenter | paul(a)pcserviceselectronics.co.uk <http://www.pcserviceselectronics.co.uk/> PC Services <http://www.gnuh8.org.uk/> GNU H8 & mailing list info <http://www.badweb.org.uk/> For those web sites you hate
From: starfire on 20 Feb 2005 10:11 "Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message news:20050220.0055.306860snz(a)pcserv.demon.co.uk... > On Saturday, in article <111f4oihcoli210(a)corp.supernews.com> > starfire151(a)cableone.net "starfire" wrote: > ....snip... > ... >>I have checked Dallas/Maxim and Xicor for EEPROM pot parts but they don't >>make such parts with multiple addresses, dual devices, EEPROM, and I2C in >>an >>SOIC package, as was my original request. I have also checked into the >>Xicor parts. Ditto. > > But it depends on what you mean by SOIC, as there are 150mil and 300mil > variants. > > Most 14-20 pin TSSOP (173mil) packages are similar to SOIC 150mil. > >>I have, in fact, done complete parametric searches on the Dallas/Maxim, >>Microchip, and Xicor sites. > >>The closest I've found is the Maxim MAX5479, which is in a different >>package > > The package style is close enough to the SOIC 150ml (if not slightly > larger) > Actually the DS1803 is also available in 14pin TSSOP > >>style. I'm putting my circuits together by hand (without using reflow >>ovens, etc.) so my package styles are necessarily somewhat limited. I >>can't >>do ball grid arrays, for instance. > > I do lots of boards by hand with SOT23-5 and even 144pin TQFP on 0.4mm > pitch. > The TSSOP is slightly larger so probably easier to hand solder, also the > pin > out probably makes isolation between load and micro easier. > > You just have to be careful and an iron which can go don to 0.2mm tip > helps > on reworking as well. > > -- > Paul Carpenter | paul(a)pcserviceselectronics.co.uk > <http://www.pcserviceselectronics.co.uk/> PC Services > <http://www.gnuh8.org.uk/> GNU H8 & mailing list info > <http://www.badweb.org.uk/> For those web sites you hate > Actually, I've done connectors at 0.5mm pitch, also. The tip of my standard Weller looked huge compared to the leads of the connector but being very careful, I managed to be successful. That was only 16 pins. I don't think I would attempt anything like a large flat pack without a much finer tip on my iron. I've done a ton of SOT23 devices. They're not a problem. Have you found any way of doing BGAs by hand or is it flat impractical? Dave
From: Paul Carpenter on 20 Feb 2005 11:02 On Sunday, in article <111ha50214jn8be(a)corp.supernews.com> starfire151(a)cableone.net "starfire" wrote: >"Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message >news:20050220.0055.306860snz(a)pcserv.demon.co.uk... >> On Saturday, in article <111f4oihcoli210(a)corp.supernews.com> >> starfire151(a)cableone.net "starfire" wrote: ....snip... >>>The closest I've found is the Maxim MAX5479, which is in a different >>>package >> >> The package style is close enough to the SOIC 150ml (if not slightly >> larger) >> Actually the DS1803 is also available in 14pin TSSOP >> >>>style. I'm putting my circuits together by hand (without using reflow >>>ovens, etc.) so my package styles are necessarily somewhat limited. I >>>can't >>>do ball grid arrays, for instance. >> >> I do lots of boards by hand with SOT23-5 and even 144pin TQFP on 0.4mm >> pitch. >> The TSSOP is slightly larger so probably easier to hand solder, also the >> pin >> out probably makes isolation between load and micro easier. >> >> You just have to be careful and an iron which can go don to 0.2mm tip >> helps >> on reworking as well. >> >Actually, I've done connectors at 0.5mm pitch, also. The tip of my standard >Weller looked huge compared to the leads of the connector but being very >careful, I managed to be successful. That was only 16 pins. I don't think >I would attempt anything like a large flat pack without a much finer tip on I use a Weller with 0.8mm tip and a JBC iron with interchangeable tips down to conical 0.2mm. Also the JBC has temperature control and keeps the iron at half temperature when the iron is on the stand, and heats to full temperature in 2 seconds. I find Elctrobe Flux pens useful for hand assembly/rework. >my iron. I've done a ton of SOT23 devices. They're not a problem. SOT23-5 are finer pitch 5 pin SOT23 devices (0.4mm pitch on one side), basically 5 pins on a SOT23. >Have you found any way of doing BGAs by hand or is it flat impractical? Impractical to do any BGA by hand as you cannot check the joints properly or be sure you you enough solder/flux on all pads to the same amount. They need good reflow ovens to heat board and device at the same time. -- Paul Carpenter | paul(a)pcserviceselectronics.co.uk <http://www.pcserviceselectronics.co.uk/> PC Services <http://www.gnuh8.org.uk/> GNU H8 & mailing list info <http://www.badweb.org.uk/> For those web sites you hate
From: starfire on 20 Feb 2005 13:37
Thanks, Paul. "Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message news:20050220.1602.306873snz(a)pcserv.demon.co.uk... > On Sunday, in article <111ha50214jn8be(a)corp.supernews.com> > starfire151(a)cableone.net "starfire" wrote: > >>"Paul Carpenter" <paul$@pcserv.demon.co.uk> wrote in message >>news:20050220.0055.306860snz(a)pcserv.demon.co.uk... >>> On Saturday, in article <111f4oihcoli210(a)corp.supernews.com> >>> starfire151(a)cableone.net "starfire" wrote: > ...snip... > >>>>The closest I've found is the Maxim MAX5479, which is in a different >>>>package >>> >>> The package style is close enough to the SOIC 150ml (if not slightly >>> larger) >>> Actually the DS1803 is also available in 14pin TSSOP >>> >>>>style. I'm putting my circuits together by hand (without using reflow >>>>ovens, etc.) so my package styles are necessarily somewhat limited. I >>>>can't >>>>do ball grid arrays, for instance. >>> >>> I do lots of boards by hand with SOT23-5 and even 144pin TQFP on 0.4mm >>> pitch. >>> The TSSOP is slightly larger so probably easier to hand solder, also the >>> pin >>> out probably makes isolation between load and micro easier. >>> >>> You just have to be careful and an iron which can go don to 0.2mm tip >>> helps >>> on reworking as well. >>> >>Actually, I've done connectors at 0.5mm pitch, also. The tip of my >>standard >>Weller looked huge compared to the leads of the connector but being very >>careful, I managed to be successful. That was only 16 pins. I don't >>think >>I would attempt anything like a large flat pack without a much finer tip >>on > > I use a Weller with 0.8mm tip and a JBC iron with interchangeable tips > down > to conical 0.2mm. Also the JBC has temperature control and keeps the iron > at > half temperature when the iron is on the stand, and heats to full > temperature > in 2 seconds. > > I find Elctrobe Flux pens useful for hand assembly/rework. > >>my iron. I've done a ton of SOT23 devices. They're not a problem. > > SOT23-5 are finer pitch 5 pin SOT23 devices (0.4mm pitch on one side), > basically 5 pins on a SOT23. > >>Have you found any way of doing BGAs by hand or is it flat impractical? > > Impractical to do any BGA by hand as you cannot check the joints properly > or be sure you you enough solder/flux on all pads to the same amount. > They need good reflow ovens to heat board and device at the same time. > > -- > Paul Carpenter | paul(a)pcserviceselectronics.co.uk > <http://www.pcserviceselectronics.co.uk/> PC Services > <http://www.gnuh8.org.uk/> GNU H8 & mailing list info > <http://www.badweb.org.uk/> For those web sites you hate > |