Hello Leon, Did you put some bypass capacitors in your design. Each time you perform an action, your parts will sink current. If the power supply has no 'reserve' to provide the current that is suddently required, the Voltage will drop in accordance. If you already have Bypass Cap, try to enlarge the capacity. Also check for routing of your board. What you describe could also come from cross talk between asynchronous functions running in parallel. You should avoid data tracks routed in parallel of clocks or power tracks. Also avoid rapidly changing signal tracks routed under critical components. Don't forget that the activity of a board 'can' indirectly be monitored trough it's power lines for example. Do not under estimate the cross talk (both capacitive and inductive coupling) between wires. One last thing, which is quit the same as putting some bypass capacitor, try to filter the power line, before and after the regulators. If capacitors are insufficient, try to use a little inductor in line with the VCC. Good luck, Vincent IDTECT 115, rue Rumur - 75002 - PARIS Tel : 01 55 34 76 64 Fax : 01 55 34 76 75 www.idtect.com -----Original Message----- From: Leon Heller [mailto:] Sent: mardi 14 septembre 2004 14:12 To: Subject: Re: [piclist] LCD Noise problem ----- Original Message ----- From: R Ramesh To: Sent: Tuesday, September 14, 2004 12:05 PM Subject: [piclist] LCD Noise problem Hi all I m using 16F877 Controller and the LCD display in my system ,my other process in the system effects the display oftenly. Can I use an buffer ( line driver between LCD and Microchip),When i check with the Osciloscope i saw all the singmal amd control line & power line of the LCD has some noise.Due to this noise the display collapse( shift by one character) after few hrs then need to restart then its ok, What type of LCD display are you using? You really need to find the source of the noise. I doubt if a buffer would help. Leon -- Leon Heller, G1HSM http://webspace.webring.com/people/jl/leon_heller/ to unsubscribe, go to http://www.yahoogroups.com and follow the instructions Yahoo! Groups Links

----- Original Message ----- From: R Ramesh To: Sent: Tuesday, September 14, 2004 12:05 PM Subject: [piclist] LCD Noise problem Hi all I m using 16F877 Controller and the LCD display in my system ,my other process in the system effects the display oftenly. Can I use an buffer ( line driver between LCD and Microchip),When i check with the Osciloscope i saw all the singmal amd control line & power line of the LCD has some noise.Due to this noise the display collapse( shift by one character) after few hrs then need to restart then its ok, What type of LCD display are you using? You really need to find the source of the noise. I doubt if a buffer would help. Leon -- Leon Heller, G1HSM http://webspace.webring.com/people/jl/leon_heller/

Hi all

I m using 16F877 Controller and the LCD display in my system ,my other process in the system effects the display oftenly.

Can I use an buffer ( line driver between LCD and Microchip),When i check with the Osciloscope i saw all the singmal amd control line & power line of the LCD has some noise.Due to this noise the display collapse( shift by one character) after few hrs then need to restart then its ok,

thanks,

ramesh

Hmmm, I don't know about Mike, but I am very interested in your interrupt-driven code (cause it drives me nuts) Kees --- bg3009 <> wrote: > Mike, > > What pic are you using for your slaves? I have > done interupt > driven PICs are they are dead easy. I developed a > generic code block > thats plug and play and works most of the times. I > can send it to > you. I designed a SMPS monitoring system based on a > 8-bit 18 leg > device with I2C monitoring, fan speed control, and a > whole lot of > funtions. And the pic performed beatifully even with > continous > pinging from the master at 750kHz from the master. > > BG > > --- In , "upand_at_them" > <upand_at_them@y...> > wrote: > > Thanks Kees. > > > > I wound up writing the routines. And, like you > said, the master > > routines aren't difficult. I had never used the > native I2C support > > of the PIC16F88 and when I realized I had one of > these in my parts > > bin and that it supported I2C I assumed it was an > easy thing to > > implement. I don't know why it isn't. > > > > Mike > > > > > > --- In , Kees Stenekes > <knalkeez@y...> wrote: > > > Mike, > > > > > > Writing i2c-master routines in bit-bang is not > so > > > hard, but writing i2c-slave routines is a hell > of a > > > job. I succeeded my own projects with multiple > > > 12f629's as slaves and a 16f628a as master, but > I have > > > to confess that my slave-routines are 'polling' > and > > > not interrupt-driven. I've been working on an > > > interrupt-version, but I did not succeed so far. > > > If you want, I can send you my routines > (assembler). > > > > > > Greetings, > > > > > > Kees Stenekes > > > > > > --- Wilson <wantoniet@y...> wrote: > > > > > > > I2C routines is complicated if you never used > it. > > > > Try type on Microchip�s > > > > web site "I2C" and you�ll find many > applications, > > > > routines and detailed > > > > documents about this issue. > > > > > > > > Try out !! > > > > > > > > > > > > > > > > > > > > Wilson Antonieti Engenharia de Desenvolvimento > Tel.: > > > > (11) 4223-5117 Fax.: > > > > (11) 4223-5103 wilson@c... Visite nosso > > > > site: www.contemp.com.br > > > > PRECIS�O AO SEU ALCANCE!!! > > > > ----- Original Message ----- > > > > From: "upand_at_them" <upand_at_them@y...> > > > > To: <> > > > > Sent: Wednesday, August 04, 2004 1:14 AM > > > > Subject: [piclist] I2C example? > > > > > > > > > > > > > I'm interested in using a 16F88 with a > couple I2C > > > > devices and, > > > > > looking through the PIC datasheet, it looks > WAY > > > > more complicated than > > > > > me just writing big-bang routines. > > > > > > > > > > Is there a simple example of using the > onboard I2C > > > > interface or > > > > > should I just write the simple big-bang > routines? > > > > > > > > > > Mike > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > to unsubscribe, go to > http://www.yahoogroups.com > > > > and follow the > > > > instructions > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > __________________________________ > > __________________________________

Yes I agree here. I think a PIC with I2C master functions will take care of timing issues and so on easily. The notes from Philips gives a detailed treatment on the subject. And it deals with important details also. Very soon, I am planning to built a home automation system for my house to control the lights, windows, basic security. BG --- In , "rtstofer" <rstofer@p...> wrote: > > The built-in support is quite complex because the hardware has to > deal with a lot of issues that may occur on the bus. Now, if you > have just one device hanging out there and you don't have some 'real- > time' requirement, bit-banging is pretty easy to code. You can find > examples all over the Internet including www.piclist.com. > > Still, the app notes from Microchip have the master code and, I > would assume, would work with your chip. In fact, one of the app > notes is for a distributed control system as might be used in a > building HVAC system. > > Philips Semiconductor invented, and has still, the best app notes on > I2C. > > --- In , "upand_at_them" <upand_at_them@y...> > wrote: > > I'm not using a PIC slave; I'm using a PIC16F88 master with a > MAX127 > > ADC slave. Which is why I thought the builtin support should have > > been easy. > > > > Mike > > > > --- In , "bg3009" <bg3009@y...> wrote: > > > Mike, > > > > > > What pic are you using for your slaves? I have done > interupt > > > driven PICs are they are dead easy. I developed a generic code > > block > > > thats plug and play and works most of the times. I can send it > to > > > you. I designed a SMPS monitoring system based on a 8-bit 18 leg > > > device with I2C monitoring, fan speed control, and a whole lot > of > > > funtions. And the pic performed beatifully even with continous > > > pinging from the master at 750kHz from the master. > > > > > > BG > > > > > > --- In , "upand_at_them" > > <upand_at_them@y...> > > > wrote: > > > > Thanks Kees. > > > > > > > > I wound up writing the routines. And, like you said, the > master > > > > routines aren't difficult. I had never used the native I2C > > support > > > > of the PIC16F88 and when I realized I had one of these in my > > parts > > > > bin and that it supported I2C I assumed it was an easy thing > to > > > > implement. I don't know why it isn't. > > > > > > > > Mike > > > > > > > > > > > > --- In , Kees Stenekes <knalkeez@y...> > > wrote: > > > > > Mike, > > > > > > > > > > Writing i2c-master routines in bit-bang is not so > > > > > hard, but writing i2c-slave routines is a hell of a > > > > > job. I succeeded my own projects with multiple > > > > > 12f629's as slaves and a 16f628a as master, but I have > > > > > to confess that my slave-routines are 'polling' and > > > > > not interrupt-driven. I've been working on an > > > > > interrupt-version, but I did not succeed so far. > > > > > If you want, I can send you my routines (assembler). > > > > > > > > > > Greetings, > > > > > > > > > > Kees Stenekes > > > > > > > > > > --- Wilson <wantoniet@y...> wrote: > > > > > > > > > > > I2C routines is complicated if you never used it. > > > > > > Try type on Microchip�s > > > > > > web site "I2C" and you�ll find many applications, > > > > > > routines and detailed > > > > > > documents about this issue. > > > > > > > > > > > > Try out !! > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Wilson Antonieti Engenharia de Desenvolvimento Tel.: > > > > > > (11) 4223-5117 Fax.: > > > > > > (11) 4223-5103 wilson@c... Visite nosso > > > > > > site: www.contemp.com.br > > > > > > PRECIS�O AO SEU ALCANCE!!! > > > > > > ----- Original Message ----- > > > > > > From: "upand_at_them" <upand_at_them@y...> > > > > > > To: <> > > > > > > Sent: Wednesday, August 04, 2004 1:14 AM > > > > > > Subject: [piclist] I2C example? > > > > > > > > > > > > > > > > > > > I'm interested in using a 16F88 with a couple I2C > > > > > > devices and, > > > > > > > looking through the PIC datasheet, it looks WAY > > > > > > more complicated than > > > > > > > me just writing big-bang routines. > > > > > > > > > > > > > > Is there a simple example of using the onboard I2C > > > > > > interface or > > > > > > > should I just write the simple big-bang routines? > > > > > > > > > > > > > > Mike > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > to unsubscribe, go to http://www.yahoogroups.com > > > > > > and follow the > > > > > > instructions > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > __________________________________ > > > > >

The built-in support is quite complex because the hardware has to deal with a lot of issues that may occur on the bus. Now, if you have just one device hanging out there and you don't have some 'real- time' requirement, bit-banging is pretty easy to code. You can find examples all over the Internet including www.piclist.com. Still, the app notes from Microchip have the master code and, I would assume, would work with your chip. In fact, one of the app notes is for a distributed control system as might be used in a building HVAC system. Philips Semiconductor invented, and has still, the best app notes on I2C. --- In , "upand_at_them" <upand_at_them@y...> wrote: > I'm not using a PIC slave; I'm using a PIC16F88 master with a MAX127 > ADC slave. Which is why I thought the builtin support should have > been easy. > > Mike > > --- In , "bg3009" <bg3009@y...> wrote: > > Mike, > > > > What pic are you using for your slaves? I have done interupt > > driven PICs are they are dead easy. I developed a generic code > block > > thats plug and play and works most of the times. I can send it to > > you. I designed a SMPS monitoring system based on a 8-bit 18 leg > > device with I2C monitoring, fan speed control, and a whole lot of > > funtions. And the pic performed beatifully even with continous > > pinging from the master at 750kHz from the master. > > > > BG > > > > --- In , "upand_at_them" > <upand_at_them@y...> > > wrote: > > > Thanks Kees. > > > > > > I wound up writing the routines. And, like you said, the master > > > routines aren't difficult. I had never used the native I2C > support > > > of the PIC16F88 and when I realized I had one of these in my > parts > > > bin and that it supported I2C I assumed it was an easy thing to > > > implement. I don't know why it isn't. > > > > > > Mike > > > > > > > > > --- In , Kees Stenekes <knalkeez@y...> > wrote: > > > > Mike, > > > > > > > > Writing i2c-master routines in bit-bang is not so > > > > hard, but writing i2c-slave routines is a hell of a > > > > job. I succeeded my own projects with multiple > > > > 12f629's as slaves and a 16f628a as master, but I have > > > > to confess that my slave-routines are 'polling' and > > > > not interrupt-driven. I've been working on an > > > > interrupt-version, but I did not succeed so far. > > > > If you want, I can send you my routines (assembler). > > > > > > > > Greetings, > > > > > > > > Kees Stenekes > > > > > > > > --- Wilson <wantoniet@y...> wrote: > > > > > > > > > I2C routines is complicated if you never used it. > > > > > Try type on Microchip�s > > > > > web site "I2C" and you�ll find many applications, > > > > > routines and detailed > > > > > documents about this issue. > > > > > > > > > > Try out !! > > > > > > > > > > > > > > > > > > > > > > > > > Wilson Antonieti Engenharia de Desenvolvimento Tel.: > > > > > (11) 4223-5117 Fax.: > > > > > (11) 4223-5103 wilson@c... Visite nosso > > > > > site: www.contemp.com.br > > > > > PRECIS�O AO SEU ALCANCE!!! > > > > > ----- Original Message ----- > > > > > From: "upand_at_them" <upand_at_them@y...> > > > > > To: <> > > > > > Sent: Wednesday, August 04, 2004 1:14 AM > > > > > Subject: [piclist] I2C example? > > > > > > > > > > > > > > > > I'm interested in using a 16F88 with a couple I2C > > > > > devices and, > > > > > > looking through the PIC datasheet, it looks WAY > > > > > more complicated than > > > > > > me just writing big-bang routines. > > > > > > > > > > > > Is there a simple example of using the onboard I2C > > > > > interface or > > > > > > should I just write the simple big-bang routines? > > > > > > > > > > > > Mike > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > to unsubscribe, go to http://www.yahoogroups.com > > > > > and follow the > > > > > instructions > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > __________________________________ > > > >

I'm not using a PIC slave; I'm using a PIC16F88 master with a MAX127 ADC slave. Which is why I thought the builtin support should have been easy. Mike --- In , "bg3009" <bg3009@y...> wrote: > Mike, > > What pic are you using for your slaves? I have done interupt > driven PICs are they are dead easy. I developed a generic code block > thats plug and play and works most of the times. I can send it to > you. I designed a SMPS monitoring system based on a 8-bit 18 leg > device with I2C monitoring, fan speed control, and a whole lot of > funtions. And the pic performed beatifully even with continous > pinging from the master at 750kHz from the master. > > BG > > --- In , "upand_at_them" <upand_at_them@y...> > wrote: > > Thanks Kees. > > > > I wound up writing the routines. And, like you said, the master > > routines aren't difficult. I had never used the native I2C support > > of the PIC16F88 and when I realized I had one of these in my parts > > bin and that it supported I2C I assumed it was an easy thing to > > implement. I don't know why it isn't. > > > > Mike > > > > > > --- In , Kees Stenekes <knalkeez@y...> wrote: > > > Mike, > > > > > > Writing i2c-master routines in bit-bang is not so > > > hard, but writing i2c-slave routines is a hell of a > > > job. I succeeded my own projects with multiple > > > 12f629's as slaves and a 16f628a as master, but I have > > > to confess that my slave-routines are 'polling' and > > > not interrupt-driven. I've been working on an > > > interrupt-version, but I did not succeed so far. > > > If you want, I can send you my routines (assembler). > > > > > > Greetings, > > > > > > Kees Stenekes > > > > > > --- Wilson <wantoniet@y...> wrote: > > > > > > > I2C routines is complicated if you never used it. > > > > Try type on Microchip�s > > > > web site "I2C" and you�ll find many applications, > > > > routines and detailed > > > > documents about this issue. > > > > > > > > Try out !! > > > > > > > > > > > > > > > > > > > > Wilson Antonieti Engenharia de Desenvolvimento Tel.: > > > > (11) 4223-5117 Fax.: > > > > (11) 4223-5103 wilson@c... Visite nosso > > > > site: www.contemp.com.br > > > > PRECIS�O AO SEU ALCANCE!!! > > > > ----- Original Message ----- > > > > From: "upand_at_them" <upand_at_them@y...> > > > > To: <> > > > > Sent: Wednesday, August 04, 2004 1:14 AM > > > > Subject: [piclist] I2C example? > > > > > > > > > > > > > I'm interested in using a 16F88 with a couple I2C > > > > devices and, > > > > > looking through the PIC datasheet, it looks WAY > > > > more complicated than > > > > > me just writing big-bang routines. > > > > > > > > > > Is there a simple example of using the onboard I2C > > > > interface or > > > > > should I just write the simple big-bang routines? > > > > > > > > > > Mike > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > to unsubscribe, go to http://www.yahoogroups.com > > > > and follow the > > > > instructions > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > __________________________________ > > >

Mike, What pic are you using for your slaves? I have done interupt driven PICs are they are dead easy. I developed a generic code block thats plug and play and works most of the times. I can send it to you. I designed a SMPS monitoring system based on a 8-bit 18 leg device with I2C monitoring, fan speed control, and a whole lot of funtions. And the pic performed beatifully even with continous pinging from the master at 750kHz from the master. BG --- In , "upand_at_them" <upand_at_them@y...> wrote: > Thanks Kees. > > I wound up writing the routines. And, like you said, the master > routines aren't difficult. I had never used the native I2C support > of the PIC16F88 and when I realized I had one of these in my parts > bin and that it supported I2C I assumed it was an easy thing to > implement. I don't know why it isn't. > > Mike > --- In , Kees Stenekes <knalkeez@y...> wrote: > > Mike, > > > > Writing i2c-master routines in bit-bang is not so > > hard, but writing i2c-slave routines is a hell of a > > job. I succeeded my own projects with multiple > > 12f629's as slaves and a 16f628a as master, but I have > > to confess that my slave-routines are 'polling' and > > not interrupt-driven. I've been working on an > > interrupt-version, but I did not succeed so far. > > If you want, I can send you my routines (assembler). > > > > Greetings, > > > > Kees Stenekes > > > > --- Wilson <wantoniet@y...> wrote: > > > > > I2C routines is complicated if you never used it. > > > Try type on Microchip�s > > > web site "I2C" and you�ll find many applications, > > > routines and detailed > > > documents about this issue. > > > > > > Try out !! > > > > > > > > > > > > > > > Wilson Antonieti Engenharia de Desenvolvimento Tel.: > > > (11) 4223-5117 Fax.: > > > (11) 4223-5103 wilson@c... Visite nosso > > > site: www.contemp.com.br > > > PRECIS�O AO SEU ALCANCE!!! > > > ----- Original Message ----- > > > From: "upand_at_them" <upand_at_them@y...> > > > To: <> > > > Sent: Wednesday, August 04, 2004 1:14 AM > > > Subject: [piclist] I2C example? > > > > > > > > > > I'm interested in using a 16F88 with a couple I2C > > > devices and, > > > > looking through the PIC datasheet, it looks WAY > > > more complicated than > > > > me just writing big-bang routines. > > > > > > > > Is there a simple example of using the onboard I2C > > > interface or > > > > should I just write the simple big-bang routines? > > > > > > > > Mike > > > > > > > > > > > > > > > > > > > > > > > > > > > > to unsubscribe, go to http://www.yahoogroups.com > > > and follow the > > > instructions > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > __________________________________ > >

Thanks Kees. I wound up writing the routines. And, like you said, the master routines aren't difficult. I had never used the native I2C support of the PIC16F88 and when I realized I had one of these in my parts bin and that it supported I2C I assumed it was an easy thing to implement. I don't know why it isn't. Mike --- In , Kees Stenekes <knalkeez@y...> wrote: > Mike, > > Writing i2c-master routines in bit-bang is not so > hard, but writing i2c-slave routines is a hell of a > job. I succeeded my own projects with multiple > 12f629's as slaves and a 16f628a as master, but I have > to confess that my slave-routines are 'polling' and > not interrupt-driven. I've been working on an > interrupt-version, but I did not succeed so far. > If you want, I can send you my routines (assembler). > > Greetings, > > Kees Stenekes > > --- Wilson <wantoniet@y...> wrote: > > > I2C routines is complicated if you never used it. > > Try type on Microchip�s > > web site "I2C" and you�ll find many applications, > > routines and detailed > > documents about this issue. > > > > Try out !! > > > > > > > > > > Wilson Antonieti Engenharia de Desenvolvimento Tel.: > > (11) 4223-5117 Fax.: > > (11) 4223-5103 wilson@c... Visite nosso > > site: www.contemp.com.br > > PRECIS�O AO SEU ALCANCE!!! > > ----- Original Message ----- > > From: "upand_at_them" <upand_at_them@y...> > > To: <> > > Sent: Wednesday, August 04, 2004 1:14 AM > > Subject: [piclist] I2C example? > > > > > > > I'm interested in using a 16F88 with a couple I2C > > devices and, > > > looking through the PIC datasheet, it looks WAY > > more complicated than > > > me just writing big-bang routines. > > > > > > Is there a simple example of using the onboard I2C > > interface or > > > should I just write the simple big-bang routines? > > > > > > Mike > > > > > > > > > > > > > > > > > > > > > to unsubscribe, go to http://www.yahoogroups.com > > and follow the > > instructions > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > __________________________________ >