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16  Products / Arduino Due / Re: 3.3v logic levels interface with standard TTL/CMOS logic - How to do it... on: January 31, 2014, 10:35:32 pm
" Please do not confuse TTL with 7400 series, TTL is transistor-transistor logic,
period.  These days noone uses TTL chips at all. "

I don't know where you get your information, but it is wrong. 4000 series is CMOS Which predates the 7400 series and is very rarely used today. Although many 74 series chips do use you CMOS logic, For instance the 54C and 74C series was CMOS.  7400 series was primarily TTL.  And if you look at the 74H series You'll find that the Numbers after the letters changed to 4xxx. The function of these numbers correspond to the 4000 series chip numbers, With very little variance.  That is a 74HC4060 will have the same function as a 4060 Chip, aThe "14 stage binary counter" . But using TTL voltage specifications.
If you want I can send you a copy of a page or two from the National Semiconductor data book from 1984 to prove it. Yes I have been dealing with them that long.

The 7400 series includes but is not limited to:

74 TTL.,
74ALS advanced low-power schottky.
74AS Advanced schottky.
74S schottky.
74L Low-power TTL.
54HC/74HC/54HCT/74HCT High-speed micro CMOS,


17  Products / Arduino Due / Re: 3.3v logic levels interface with standard TTL/CMOS logic - How to do it... on: January 31, 2014, 05:19:29 pm
Note: the 74LVC245 Is a "Octal bus transceiver with direction pin with 5-volt tolerant inputs/outputs 3-State".
It is not specifically a logic shifter for individual bits. It will Shift the logic for a entire bite. Which is not recommended For a microcontroller, because any bit maybe set for output or input. If any two outputs are connected together it could cause problems or damage the microcontroller..Unless you are intending to shift one entire bite at a time, and all Bits are known to be either input or output, Do not use it.
Also note: This chip needs to be powered by 3.3 votes only.

Hope this helps.
18  Products / Arduino Due / Re: 3.3v logic levels interface with standard TTL/CMOS logic - How to do it... on: January 31, 2014, 04:14:38 pm
This problem has been around since the early days of logic circuits.
When it comes to CMOS chips, There is no easy answer.
The original CMOS chips Ranged in voltage from 15V  and in some cases up to 30V.
I do not recommend using the older chips. However, current CMOS chips will run at 15V or 5V.
I have never tried to run true CMOS at 3.3V. If you're referring to the 74H series which is a CMOS -based " TTL " series, They normally run at 5V, check your data sheet. Some of these chips will run fine at 3.3 V.  Even if you run them at 5V, Going from 3.3 V to 5 V should not give you a problem. However, you will need a voltage divider when going in the opposite direction. A level shifter is always recommended.

All 7400 series TTL logic runs at 5V and maybe less, depending on the series. It used to be pretty easy to keep up with the 74xx series and the voltage that they would run at.  Now there are two many 74xx series to keep up with. Check the data sheet for specific specifications.

Note: some TTL chips put out a small current from the input side. The output of the preceding chip either pulls it low or forces it to go high. This voltage can cause erratic output if the input is not tied to either a positive or negative voltage. If the gate is not in use, always tie the input so it produces a LOW output. For this reason a logic shifter is always recommended when going from one voltage to another.

Hope this helps.

19  Products / Arduino Due / Re: Can Arduino Due libraries be used on Atmel Studio? on: January 30, 2014, 05:02:47 pm
Note: an apparent bug has been found in the current version of Visual micro.
The bug was identified by someone in the visual micro group.
Apparently visual micro has problems when reading libraries using all  capital letters.
I have confirmed the problem When trying to compile the " UTFT.h " library.
Changing the library name to lowercase letters fixed the problem.

Hope this helps someone.

20  Products / Arduino Due / Re: Can Arduino Due libraries be used on Atmel Studio? on: January 18, 2014, 09:10:21 pm
The current Atmel studio references all board layouts relative to the Arduino library. If you do not have the Arduino development software installed, The Atmel studio Will not reference any libraries. You must specify which version of The Arduino I'd you are using.  If you have the current version, Three drop-down combo boxes Will be available to you. the first should be To select which I'd you are using.   Click the drop-down arrow and select configuration manager. A new window will open That has a drop-down list box, Displaying several options as follows, Arduino 1.1.x , Arduino 1.5.x . Select Arduino 1.5.x.  The next line will ask you where the file is located.  Just fill it in.  The Next line will ask for an alternative location. You can leave this line blank. Hit okay.

Now select which version of the Arduino software you are using.

All libraries should now be available and appear in the proper location.

Hope this helps.
21  Products / Arduino Due / Has anyone Created a Due Library for the TM1638 LED Display Modules. on: January 06, 2014, 10:58:27 pm
Has anyone successfully used the TM1638 LED Display Modules With the Arduino Due.
I know it will work running at 3.3 V.  I have a couple of projects that it would be perfect for,
 But can't get it to work with the due. I'm more of a hardware guy, not much of a Programmer.
Any help would be appreciated.

Thank you..
22  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: November 04, 2013, 09:00:28 pm
Unfortunately I have not used the PWM function for that display. My best suggestion is to make sure your software/hardware is functioning correctly. Connected either to an oscilloscope to see what your output is or connect a small LED with a current drop resister and see if you can very the output.
If you set the PWM for 100%,  the display backlight should come on. That is if your circuit is functioning properly. My only other thought is that the due does not put out enough current to adequately drive that circuit. It may need some kind of buffer, such as a logic level converter to drive it properly.

I hope this helps.

23  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: November 03, 2013, 09:23:36 pm
If I read the schematic right, jumper 3, 4 and 5 Are all connected to the same pin on the display.
JP3 Is connected to 5V.
JP4 Is connected to 3.3V. " Default ".
JP5 is connected to the PWM. " CN4, Pen7 ".
Only one jumper can be used at a time. All other jumpers must be disconnected.

Note: 3.3 V should turn on the LCD backlight. If it does not come on you may have something wrong with your display/Adapter board.

Hope this helps.


24  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: May 01, 2013, 07:19:00 pm
That answers a question that I asked in another post. The schematic shows one thing, but the documents show something else. Their documentation is kind of vague and sporadic. Thankfully there are people in this group that has experimented enough and is willing to post the results. Thank you for that tidbit it will be very helpful to me and hopefully to others. Maybe someone will sort through all of this information and write a good tutorial.

every little bit helps.

25  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: May 01, 2013, 04:59:36 pm
That would be a good way of doing it, but my project, a (DRO), is a standalone unit with maybe a USB host set up. I'm not planning on using the USB to power my project. I have a 9 V 3A power supply which will be more than enough power. I also need 1.5V, 3.3V, 5V, 9V power to be available if  needed, external of the Arduino. I won't be pulling much current, and some voltage may not be needed for some applications. I would also like a external reset switch to be available.

26  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: May 01, 2013, 12:26:05 am
According to the schematic, the Arduino due uses a NPC1117ST33T3G 3.3V regulator. According to the datasheet, this regulator is rated at 1A. since it is a linear regulator it generates a lot of heat, so replacing this regulator would not do much good.

My thought was to replace the power supply header on the adapter board with one that is extra long and bent to provide a place for external connectors. By snipping off the 3.3V pen that would plug into the Arduino due board, you would isolate the power going to the display. Now it can be connected to an external PWM power supply adjusted to 3.3 V. This type regulator does not get as hot and can produce a very stable voltage. And since you replaced the entire power header, you get access to the VIN,GND, master reset, 3.3V  "IOREF PIN low current" and 5V power from the Arduino due as well.

This should eliminate the heat problem caused by pulling too much current from the due board.

27  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: April 30, 2013, 08:49:47 pm
" I'm also having major problems with my Tajuino board which gets VERY hot and sometimes takes 5 or 6 attempts at uploading etc. "

I have also noticed that the 3.3 V regulator gets very hot on my Arduino due. I think the 7 inch display draws too much power for the due to realistically handle on a long-term basis. I'm not sure if a heatsink would correct the problem, So I plan to isolate the 3.3 V regulated output from the due and connect it to an external regulated power supply.  3A regulated Power supplies are cheap, and should eliminate the heat problem.

28  Using Arduino / Programming Questions / Re: Problems creating a library on: April 29, 2013, 06:08:31 pm
Question: according to the CTE shield schematic, TP_DIN is on pen 4, and is shared with the SD_CS function. But everyone uses pen 32, Which is labeled DB8. As shown in your sketch 
UTouch myTouch(6,5,32,3,2);
. Shouldn't it read
UTouch myTouch(6,5,4,3,2);
instead, or is there a problem with my schematic.

The data in function to the touchscreen controller may not be used much but it has a purpose. If you set it up using the wrong pin it may functionally be correct until you need to write a command to the touch controller. Then a problem will show up. If you're going to adapt the drivers you should use the correct pin numbers.

29  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: April 28, 2013, 09:06:56 pm
What really bugs me about their drivers, is that their demo shows it in the correct orientation. They either mirrored everything after the demo was made, or corrected the drivers for the demo but never applied the corrections to the drivers they offer us.

They seem to have decent product, but they are getting a bad reputation with their drivers. Not asking for drivers that make it work like an iPad, just basic functionality that we can use in our programs. And if you're going to use someone else's drivers for your hardware, don't render their functions unusable. Is that too much to ask.

30  Products / Arduino Due / Re: Announcement: CTE has updated their drivers. on: April 23, 2013, 06:42:52 pm

I obtained the parameters from this post, " updated library UTFT version 2.1 with a CTE shield " at,158782.0.html.
Download the file given, and go to the " tft_drivers "directory. Then go down to the directory that matches the controller for your LCD, open the file that corresponds to your LCD resolution. Compare these parameters to the parameters in the "CTE UTFT" drivers. Change any parameters that do not match.

Note: I believe the 5" and 7" TFT LCDs use the same controllers and should use the same parameters.

There is also a discussion about these parameters under this post " FIXED: SSD1963 controller with 7" TFT (horizontally mirrored image) ". at

This is the best information I can give you. Since I am still learning "C" myself I can only pass on the information that I get. Fortunately others with better skills has posted really good information. And by the way thanks to those who have contributed their knowledge, it has really helped me.  Other than that you'll just have to do your homework just like I did.

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