3 volts lcd displays

**jmurba** · 17th January 2007, 21:39

Quote: (Originally Posted by stephengrenfell)

Jarod is right the Intersema device is not true SPI - the main differences are that there is no CS instead you need to turn the SPI clock off (the Intersema spec suggest using a tri-state buffer for this), and when the module is ready to send data (i.e. after a measurement sample cycle) it changes logic level on tx data pin - so you need to detect this with an interrupt. You can still use it with other devices on the SPI bus provided you deal with these two issues. This is not insurmountable - it just needs soem careful thought.

Stephen

Hi steven,

anyway I have the samples, so i will try in the real world , every thing is explained in the application notes so, with the help of the alcatel space electronic enginers that usualy help us it won't take long before we manage to get the depth on the display...
anyway deco is a bonus for we have working ppo2 gauges and computers to dive, so deco is just a way to go on thinking and playing.

regards

ps: we should be able to dive on sunday...

à dimanche

salut

jean mi

**jmurba** · 17th January 2007, 21:46

Quote: (Originally Posted by stephengrenfell)

Jean-Mi,

There are plenty of Graphic LCD modules that work at 3v (like the one I showed you). But you are right there does not seem to be any character LCD display modules that work at 3v. This might be becuase the driver IC (built into the module) only exists for 5v. You could use a graphic LCD module - but you will need the SW to create the characters. Otherwise you could use a DC-DC charge pump (small IC) to double your 3v and use this to drive your LCD (they will operate at up to 7V (normally).

Stephen

Well you are rigth maybye should I use a graphic lcd....i will try to use one on my test board.....not as easy as the charactere ones....
anyway.

regards

jean mi

***jradomski*** · 18th January 2007, 04:54

Quote: (Originally Posted by jmurba)

Well you are rigth maybye should I use a graphic lcd....i will try to use one on my test board.....not as easy as the charactere ones....
anyway.

regards

jean mi

Graphic LCDs allow the use of different font sizes but they have their drawbacks as well.. Depending on the complexity of the output you want to allow, the required code support can grow quite large.. Then you have to take into account the entire screen MUST be buffered.. It can be stored in the screen itself, but then you need to read from the screen, make your changes then write them back, this is the slowest but uses less ram.. If you don;t use the ram within the LCD, now you must store the buffer in your MCU, and take into account how much ram do yo hvae available.. alot of microcontrollers have 2k or under ram and this is not enough for a display and the ram for your program needs.. even a simple monochrome 240x128 display needs 3840 bytes of ram..

stephengrenfell · 18th January 2007, 07:16

Quote: (Originally Posted by jradomski)

Graphic LCDs allow the use of different font sizes but they have their drawbacks as well.. Depending on the complexity of the output you want to allow, the required code support can grow quite large.. Then you have to take into account the entire screen MUST be buffered.. It can be stored in the screen itself, but then you need to read from the screen, make your changes then write them back, this is the slowest but uses less ram.. If you don;t use the ram within the LCD, now you must store the buffer in your MCU, and take into account how much ram do yo hvae available.. alot of microcontrollers have 2k or under ram and this is not enough for a display and the ram for your program needs.. even a simple monochrome 240x128 display needs 3840 bytes of ram..

Hi

I agree there are drawbacks, in terms of programming complexity, to using graphic displays wrt fonts. However if you are using a compiler which supports characters on graphic displays and you accept not to be too fancy about different font sizes (such as sticking to a single page height and/or uisng only numbers for bigger charaters) then the complexity is reduced. You can also use program memory to store your font (some PIC have up to 64k) to avoid using the precious data RAM. Yes the display has a local RAM to store whatever is being displayed - in the same way a character display does - but it is not mandatory to read the contents of the display first you can write data directly over whatever is already on the display - same as you would with a charater display. It would be very inefficient to buffer the whole bitmap in data memory.
Just my two cents.

Stephen

If you limit it to one size font and treat it as if it was a character display, then you dont have to read it back and assuming the byte you are sending is not part of text or graphics that have to remain in place (vertically or horizontally depending on the layout of the bitmap)

stephengrenfell · 18th January 2007, 07:22

Quote: (Originally Posted by jmurba)

Well you are rigth maybye should I use a graphic lcd....i will try to use one on my test board.....not as easy as the charactere ones....
anyway.

regards

jean mi

Salut,

Be aware there are different driver ICs for graphiic LCDs - if you intend to use any built-in functions provided by your compiler you should check which one(s) are supported (possibly only KS0108 ??).

Ciao

Stephen

***jradomski*** · 18th January 2007, 07:34

Quote: (Originally Posted by stephengrenfell)

Salut,

Be aware there are different driver ICs for graphiic LCDs - if you intend to use any built-in functions provided by your compiler you should check which one(s) are supported (possibly only KS0108 ??).

Ciao

Stephen

I have used several mainstream c compilers (IAR, ROWLEY, KIEL, Archelon (quadravox) ect) and assemblers and have never seen built in LCD support.. Usually you are on your own or go out an buy a library such as those offered by companies like ramtex... I prefer the ks07xx families myself..

For simplicity its hard to beat a character oriented display.. once multiple font sizes make sense, graphic displays fit the bill..

stephengrenfell · 18th January 2007, 07:40

Quote: (Originally Posted by jmurba)

Hi steven,

anyway I have the samples, so i will try in the real world , every thing is explained in the application notes so, with the help of the alcatel space electronic enginers that usualy help us it won't take long before we manage to get the depth on the display...
anyway deco is a bonus for we have working ppo2 gauges and computers to dive, so deco is just a way to go on thinking and playing.

regards

ps: we should be able to dive on sunday...

à dimanche

salut

jean mi

Salut,

You're right it's nice to play and yes the applications note explains how to "pad out" the bit stream with leading zeros into bytes.

á dimanche

Stephen

stephengrenfell · 18th January 2007, 07:45

Quote: (Originally Posted by jradomski)

I have used several mainstream c compilers (IAR, ROWLEY, KIEL, Archelon (quadravox) ect) and assemblers and have never seen built in LCD support.. Usually you are on your own or go out an buy a library such as those offered by companies like ramtex... I prefer the ks07xx families myself..

mikro C and Proton Basic Pro both support use of KS01018 based 64x128 graphic displays connected via parallel interface - I agree KS07xx are better but then you need to adapt the built-in functions or write your own.

Stephen

***jradomski*** · 18th January 2007, 08:00

Quote: (Originally Posted by stephengrenfell)

mikro C and Proton Basic Pro both support use of KS01018 based 64x128 graphic displays connected via parallel interface - I agree KS07xx are better but then you need to adapt the built-in functions or write your own.

Stephen

I don't program in basic and have never heard of mikro c.. I have always stayed with mainstream vendors because they usually support multiple architectures, high level of technical support, and the code is portable across them albeit usually at a "professional" price as well...

**jmurba** · 18th January 2007, 08:41

Quote: (Originally Posted by stephengrenfell)

Hi

I agree there are drawbacks, in terms of programming complexity, to using graphic displays wrt fonts. However if you are using a compiler which supports characters on graphic displays and you accept not to be too fancy about different font sizes (such as sticking to a single page height and/or uisng only numbers for bigger charaters) then the complexity is reduced. You can also use program memory to store your font (some PIC have up to 64k) to avoid using the precious data RAM. Yes the display has a local RAM to store whatever is being displayed - in the same way a character display does - but it is not mandatory to read the contents of the display first you can write data directly over whatever is already on the display - same as you would with a charater display. It would be very inefficient to buffer the whole bitmap in data memory.
Just my two cents.

Stephen

If you limit it to one size font and treat it as if it was a character display, then you dont have to read it back and assuming the byte you are sending is not part of text or graphics that have to remain in place (vertically or horizontally depending on the layout of the bitmap)

Hi steven and all,

You are perfectly right, but your priority are not mines
As a matter of fact you have chosen the shearwater that is a good gauge/computer.
I did not cause I definitly wanted audible alarms.
as you know the audible alarms are working now, and the hud can be plugged on the gauge with no other works then installing a cable in the hud cableglang and a small led pot that hugue as juste finished.
so my problem is now deco , only one of my hs explorerz survived and i will soon have no deco computer solution (when the second hs will die....).
so the displays are not my prirority as it is for you.
there are very nice character displays that will be far enough for my use.
So I want to go ahead and implement the deco as soon as possible in the tube.
Denis has arranged bulhman the deco algos , and it is ready to get in the pic provided we managed to use the spi.
and in my opinion it won't be really difficult... if we get a shadow of a problem, as usual alactel Space Cannes is our direct fast and efficient solution... those kind of a probleme will make them laugh.
once de deco is in the tube of course we will be able to play so as to render the gauge nicer then it is, and of course smaller then it is using cms, small and extern graphic displays, but for the moment it is not my priority.

tu passes à la maison samedi soir ?

regards

jean mi

17th January 2007, 21:39	#21 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 925	Re: 3 volts lcd displays Quote: (Originally Posted by stephengrenfell) Jarod is right the Intersema device is not true SPI - the main differences are that there is no CS instead you need to turn the SPI clock off (the Intersema spec suggest using a tri-state buffer for this), and when the module is ready to send data (i.e. after a measurement sample cycle) it changes logic level on tx data pin - so you need to detect this with an interrupt. You can still use it with other devices on the SPI bus provided you deal with these two issues. This is not insurmountable - it just needs soem careful thought. Stephen Hi steven, anyway I have the samples, so i will try in the real world , every thing is explained in the application notes so, with the help of the alcatel space electronic enginers that usualy help us it won't take long before we manage to get the depth on the display... anyway deco is a bonus for we have working ppo2 gauges and computers to dive, so deco is just a way to go on thinking and playing. regards ps: we should be able to dive on sunday... à dimanche salut jean mi
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17th January 2007, 21:46	#22 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 925	Re: 3 volts lcd displays Quote: (Originally Posted by stephengrenfell) Jean-Mi, There are plenty of Graphic LCD modules that work at 3v (like the one I showed you). But you are right there does not seem to be any character LCD display modules that work at 3v. This might be becuase the driver IC (built into the module) only exists for 5v. You could use a graphic LCD module - but you will need the SW to create the characters. Otherwise you could use a DC-DC charge pump (small IC) to double your 3v and use this to drive your LCD (they will operate at up to 7V (normally). Stephen Well you are rigth maybye should I use a graphic lcd....i will try to use one on my test board.....not as easy as the charactere ones.... anyway. regards jean mi
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18th January 2007, 04:54	#23 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,115	Re: 3 volts lcd displays Quote: (Originally Posted by jmurba) Well you are rigth maybye should I use a graphic lcd....i will try to use one on my test board.....not as easy as the charactere ones.... anyway. regards jean mi Graphic LCDs allow the use of different font sizes but they have their drawbacks as well.. Depending on the complexity of the output you want to allow, the required code support can grow quite large.. Then you have to take into account the entire screen MUST be buffered.. It can be stored in the screen itself, but then you need to read from the screen, make your changes then write them back, this is the slowest but uses less ram.. If you don;t use the ram within the LCD, now you must store the buffer in your MCU, and take into account how much ram do yo hvae available.. alot of microcontrollers have 2k or under ram and this is not enough for a display and the ram for your program needs.. even a simple monochrome 240x128 display needs 3840 bytes of ram.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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18th January 2007, 07:16	#24 (permalink)
stephengrenfell New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Nov 2005 Location: france Posts: 11	Re: 3 volts lcd displays Quote: (Originally Posted by jradomski) Graphic LCDs allow the use of different font sizes but they have their drawbacks as well.. Depending on the complexity of the output you want to allow, the required code support can grow quite large.. Then you have to take into account the entire screen MUST be buffered.. It can be stored in the screen itself, but then you need to read from the screen, make your changes then write them back, this is the slowest but uses less ram.. If you don;t use the ram within the LCD, now you must store the buffer in your MCU, and take into account how much ram do yo hvae available.. alot of microcontrollers have 2k or under ram and this is not enough for a display and the ram for your program needs.. even a simple monochrome 240x128 display needs 3840 bytes of ram.. Hi I agree there are drawbacks, in terms of programming complexity, to using graphic displays wrt fonts. However if you are using a compiler which supports characters on graphic displays and you accept not to be too fancy about different font sizes (such as sticking to a single page height and/or uisng only numbers for bigger charaters) then the complexity is reduced. You can also use program memory to store your font (some PIC have up to 64k) to avoid using the precious data RAM. Yes the display has a local RAM to store whatever is being displayed - in the same way a character display does - but it is not mandatory to read the contents of the display first you can write data directly over whatever is already on the display - same as you would with a charater display. It would be very inefficient to buffer the whole bitmap in data memory. Just my two cents. Stephen If you limit it to one size font and treat it as if it was a character display, then you dont have to read it back and assuming the byte you are sending is not part of text or graphics that have to remain in place (vertically or horizontally depending on the layout of the bitmap) Last edited by jradomski : 18th January 2007 at 07:27.
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18th January 2007, 07:22	#25 (permalink)
stephengrenfell New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Nov 2005 Location: france Posts: 11	Re: 3 volts lcd displays Quote: (Originally Posted by jmurba) Well you are rigth maybye should I use a graphic lcd....i will try to use one on my test board.....not as easy as the charactere ones.... anyway. regards jean mi Salut, Be aware there are different driver ICs for graphiic LCDs - if you intend to use any built-in functions provided by your compiler you should check which one(s) are supported (possibly only KS0108 ??). Ciao Stephen
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18th January 2007, 07:34	#26 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,115	Re: 3 volts lcd displays Quote: (Originally Posted by stephengrenfell) Salut, Be aware there are different driver ICs for graphiic LCDs - if you intend to use any built-in functions provided by your compiler you should check which one(s) are supported (possibly only KS0108 ??). Ciao Stephen I have used several mainstream c compilers (IAR, ROWLEY, KIEL, Archelon (quadravox) ect) and assemblers and have never seen built in LCD support.. Usually you are on your own or go out an buy a library such as those offered by companies like ramtex... I prefer the ks07xx families myself.. For simplicity its hard to beat a character oriented display.. once multiple font sizes make sense, graphic displays fit the bill.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated. Last edited by jradomski : 18th January 2007 at 07:46.
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18th January 2007, 07:40	#27 (permalink)
stephengrenfell New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Nov 2005 Location: france Posts: 11	Re: 3 volts lcd displays Quote: (Originally Posted by jmurba) Hi steven, anyway I have the samples, so i will try in the real world , every thing is explained in the application notes so, with the help of the alcatel space electronic enginers that usualy help us it won't take long before we manage to get the depth on the display... anyway deco is a bonus for we have working ppo2 gauges and computers to dive, so deco is just a way to go on thinking and playing. regards ps: we should be able to dive on sunday... à dimanche salut jean mi Salut, You're right it's nice to play and yes the applications note explains how to "pad out" the bit stream with leading zeros into bytes. á dimanche Stephen
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18th January 2007, 07:45	#28 (permalink)
stephengrenfell New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Nov 2005 Location: france Posts: 11	Re: 3 volts lcd displays Quote: (Originally Posted by jradomski) I have used several mainstream c compilers (IAR, ROWLEY, KIEL, Archelon (quadravox) ect) and assemblers and have never seen built in LCD support.. Usually you are on your own or go out an buy a library such as those offered by companies like ramtex... I prefer the ks07xx families myself.. mikro C and Proton Basic Pro both support use of KS01018 based 64x128 graphic displays connected via parallel interface - I agree KS07xx are better but then you need to adapt the built-in functions or write your own. Stephen
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18th January 2007, 08:00	#29 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,115	Re: 3 volts lcd displays Quote: (Originally Posted by stephengrenfell) mikro C and Proton Basic Pro both support use of KS01018 based 64x128 graphic displays connected via parallel interface - I agree KS07xx are better but then you need to adapt the built-in functions or write your own. Stephen I don't program in basic and have never heard of mikro c.. I have always stayed with mainstream vendors because they usually support multiple architectures, high level of technical support, and the code is portable across them albeit usually at a "professional" price as well... __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
(Offline)

18th January 2007, 08:41	#30 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 925	Re: 3 volts lcd displays Quote: (Originally Posted by stephengrenfell) Hi I agree there are drawbacks, in terms of programming complexity, to using graphic displays wrt fonts. However if you are using a compiler which supports characters on graphic displays and you accept not to be too fancy about different font sizes (such as sticking to a single page height and/or uisng only numbers for bigger charaters) then the complexity is reduced. You can also use program memory to store your font (some PIC have up to 64k) to avoid using the precious data RAM. Yes the display has a local RAM to store whatever is being displayed - in the same way a character display does - but it is not mandatory to read the contents of the display first you can write data directly over whatever is already on the display - same as you would with a charater display. It would be very inefficient to buffer the whole bitmap in data memory. Just my two cents. Stephen If you limit it to one size font and treat it as if it was a character display, then you dont have to read it back and assuming the byte you are sending is not part of text or graphics that have to remain in place (vertically or horizontally depending on the layout of the bitmap) Hi steven and all, You are perfectly right, but your priority are not mines As a matter of fact you have chosen the shearwater that is a good gauge/computer. I did not cause I definitly wanted audible alarms. as you know the audible alarms are working now, and the hud can be plugged on the gauge with no other works then installing a cable in the hud cableglang and a small led pot that hugue as juste finished. so my problem is now deco , only one of my hs explorerz survived and i will soon have no deco computer solution (when the second hs will die....). so the displays are not my prirority as it is for you. there are very nice character displays that will be far enough for my use. So I want to go ahead and implement the deco as soon as possible in the tube. Denis has arranged bulhman the deco algos , and it is ready to get in the pic provided we managed to use the spi. and in my opinion it won't be really difficult... if we get a shadow of a problem, as usual alactel Space Cannes is our direct fast and efficient solution... those kind of a probleme will make them laugh. once de deco is in the tube of course we will be able to play so as to render the gauge nicer then it is, and of course smaller then it is using cms, small and extern graphic displays, but for the moment it is not my priority. tu passes à la maison samedi soir ? regards jean mi
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