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1  Using Arduino / Displays / Re: Help w/ Display (Drivers SPLC780D OR ST7066U) on: April 14, 2014, 11:12:03 pm
You aren't providing much information.  Are you sure that the current drain of the backlight isn't causing your supply voltage to sag?


I thought about this a little more, I have a regulator circuit on this to step down to 3v... Now, it's working perfect! Well other than I had to change the resistor on the contrast. When I have the LCD on the text disappears and when I have it off it works fine. I have to find the right resistance that will work for both. Not really a big deal. Thanks for the help Floresta!
2  Using Arduino / Displays / Re: Help w/ Display (Drivers SPLC780D OR ST7066U) on: April 14, 2014, 10:37:33 pm
Yes, Voltage is good. The display is working fine, it's just displaying random nonsense. What information could I provide you that would help with diagnosing the issue? I really do appreciate your help on this!
3  Using Arduino / Displays / Re: Help w/ Display (Drivers SPLC780D OR ST7066U) on: April 14, 2014, 09:39:38 pm
According to the data sheet that you linked to this is a 3.3v device.  Have you taken that into account?


Yes sir.
4  Using Arduino / Displays / Help w/ Display (Drivers SPLC780D OR ST7066U) on: April 14, 2014, 07:24:40 pm
I have just recently purchased some displays from New Haven Display and the drivers listed are SPLC780D OR ST7066U, from doing some reading prior to purchase, I saw that it is compatible to the Arduino because it's the same coding for the HD44780 driver (if I worded that incorrectly I apologize). I had a sketch running already that had a HD44780 screen on it and wanted to change the screen out to this new 4x20 display I purchased (NHD-0420AZ-FL-GBW-3V3). When I hooked it up, to no surprise it was NOT working properly. I tinkered around a little, did some reading (which has confused me more) and here I am!

To make this easier, I'm working off of the "Hello World" sketch which has the pin out as follows:
 * LCD RS pin to digital pin 12
 * LCD Enable pin to digital pin 11
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * LCD R/W pin to ground
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)

The display is on, and working it just has symbols and blacked out segments...

Here is the datasheet from the LCD display:

Any help would be much appreciated!  If I can supply any additional information please let me know what you need. Thank you in advanced for your help!

5  Using Arduino / Displays / Re: Arduino Mini Pro 3.3v LCD? on: April 10, 2014, 10:26:43 pm
I found one on sale at

The only thing that made me second guess, was the Controller/Driver: SPLC780D OR ST7066U, I wasn't positive that it would be compatible. From what I have read this would not be an issue, so I picked up 2 of them. I was a fan of this model because it only needs 2.7v min with typical being 3v and max at 3.3v and low mA so it won't kill the battery life either. It's perfect for my application. I really hope I don't have any issues with the drivers though... Staying positive and keeping my fingers crossed.

6  Using Arduino / Displays / Re: Arduino Mini Pro 3.3v LCD? on: April 10, 2014, 10:16:20 am
Sounds good, I'll take a look. As for the 4.18v max, that would be the max output voltage of a 18650 battery I'm using for the project. At full charge they ring in at 4.18v. Thanks again for the help!
7  Using Arduino / Displays / Arduino Mini Pro 3.3v LCD? on: April 10, 2014, 08:34:11 am
I'm looking into some lower voltage options from the 5v Arduino Uno. I was looking at the Arduino Pro Mini @ 3.3v however, I was wondering if anyone knows anything in regards to a compatible LCD screen it doesn't have to be 16x2, I'm really just looking for an LCD that would be able to run from 3.3v minimum, and maybe like 4.18 max. If anyone has any ideas please let me know, Thank you!
8  Using Arduino / Displays / Re: DV-20208 on: March 26, 2014, 09:28:50 am
Floresta, you're correct, I was leaving pin 3 open. I jumped it to pin 1 and I'm now displaying. Thank you very much for the help my friend! I hope you're enjoying the WNY weather as much as I! LOL!!!
9  Using Arduino / Displays / Re: DV-20208 on: March 23, 2014, 06:39:26 pm
Thank you for the help, I have to wait until my son goes to sleep for me to work on it. This is the LCD I purchased (please see the attached link).
10  Using Arduino / Displays / DV-20208 on: March 23, 2014, 01:38:44 pm
I'm having some issues getting this LCD screen to work and I was not able to find much about this particular model so I figured I would give it a shot on the forum.
First let me advise this is the first time working with a LCD display. I recently picked up a DV-20208 (HD44780), not really thinking much of it because I know the Arduino Uno is compatible with the HD44780. When I hook it all up to the "Hello World" sketch for testing purposes I'm not getting anything on the display what-so-ever. Has anyone picked up this model in the past? Do you know if this is in fact compatible with the Arduino? Any help or guidance with this is much appreciated. Thank you in advanced for your help.   
11  Using Arduino / Project Guidance / Re: PWM Servo via IR on: June 30, 2012, 08:24:23 am
Please tell me you're not trusting firearm safety to your programming skills

When you put it that way, you make this project sound very unsafe! HAHAHA! Well, where my lack of skills are in programing, I'm very confident in my hardware skills. I have put a lot of thought into this project in terms of safety. First of all the sides are labeled, and when the project goes live the sides that will be in the line of fire will be red, so if your able to see the red, it clearly is in the wrong position. With the servo only being able to reach 180 degrees you have 180 degrees of safety. Also, the servo that controls the trigger has a main power safety on it, where there is no power going to it at all until the safety is released, via the IR signal followed by another signal to pull the trigger. This was a thought in the event of any kind of EMS noise, or in the event the trigger button was pushed on accident. Both run off of relays that have an LED so you know the constant state of the safety and the position of the trigger servo at all times and will be clearly visible from 20 feet away where the shooter will be positioned. This clearly can be very unsafe if not used properly, and I have been shooting firearms and practicing safety since I was 8 years old, I come from a background of law enforcement and was taught at a very young age. I'm very confident in my construction and the measures of safety that I took thus far. If there is any kind of issue what-so-ever, the firing pin will never see the firearm while in the unit. This is not a toy and believe me I'm well aware of that, I'm not a kid and I know safety is a priority, this is why I'm taking my time on the project and making sure that everything is 100%. At any point I see this to be too unsafe, it will never be live. But truly, thank you for showing concern about my safety, believe me I'm much more concerned, for it's my one life I live.
12  Using Arduino / Project Guidance / Re: PWM Servo via IR on: June 30, 2012, 02:05:02 am
Well, I have always enjoyed shooting guns. Back in 2006 I had a unfortunate accident (cleaning up tree debris after hurricane Katrinain New Orleans) and I lost my right index finger so I have a problem shooting smaller handguns. I'm building this "IR turret" for a .25 caliber handgun that has been collecting dust since my accident. Honestly, the only reason why I started this is because I was loosing interest in learning how to do programming by making LEDs blink. So, I went looking around the house for something to make that would be very rewarding at the end of the project. I stubbled accross my hand gun collection and said "a turret for my. 25 would be pretty cool". Now, a month and a half later this is where I'm at. If you want to give me your email address, I will send you some pictures and or videos of my progress thus far (in the AM). I have removed the firing pin from the gun so it's safer until I get the project done and I will re-assemble the gun and bring it out to our land in the sticks, stand a good safe distance (hence the IR), and bangoff some rounds! I can't tell you how the anticipation of that day is just eating at me now. It has become an addiction, working on this with every spare moment I have. Lol! I have learned more in the month and a half, since the start of this project than I have playing with LEDs for the 3 months prior.
13  Using Arduino / Project Guidance / Re: PWM Servo via IR on: June 30, 2012, 01:49:36 am
Yea, I was viewing some tutorials and reading through some blogs, fourms and webpages while I was working hard at work today, lol. I saw something in there that I kind of liked for the math part of it. I will post it in the AM though, if you don't mind me picking your brain a little more, could you tell me if something like this would work in a sketch like this and why or why not it would or would not work. I'm trying to learn as much as I can and people that I know with the acception of one person looks at me like I have 3 eyes when I talk about anything related to my project.

Again, I can't thank you enough for all your help and patients with me. You're AWESOME and I hope to absorbe enough knowladge to be proficient in programming, to help people in the future. I have no formal background in any kind of electronics. However, due to my interests in them, I have come a long way since 2007. I find it to be very satisfying that I am self taught and people like you have been giving me the guidance in new ventures since I have started working on desktop computers back then, to BGA welding, and todays Arduino/C Programming . If it wasn't for people like you, I wouldn't be able to have a very nice extra income monthly, or extend my hobbies like this. I truly am greatful for your help, more than I can express. Thank you for everything. If you ever have any questions regarding PCs or re-flowing/ re-balling BGAs please let me know, I work on everything from Tvs to portable devices and if you ever want to run something by someone please let me help you, as payment for helping me with programming.

My 4 month old son woke up so I'm going to have to have to get at you in the AM! Thanks again!
14  Using Arduino / Project Guidance / Re: PWM Servo via IR on: June 29, 2012, 10:34:47 pm
Well, I figured out why the PanServo was not working. It wasn't getting enough power. I hooked it up to an external power supply and it works just fine now. But, with the "if" statements that I have it's going all the way to one side with a single press of a button and then all the way to the other side with the other button, single pressed. I'm going to try and get the math down right on it so it will move 15 degrees every time I hit a button and maybe I will go nuts and program a swing in there along with a stop.
15  Using Arduino / Project Guidance / Re: PWM Servo via IR on: June 29, 2012, 12:17:13 pm
I took a look at the signal going to the servo with my o-scope and AWOL is 100% correct, I got a ton of noise on there. Now, when I reset the Arduino or I load the sketch it moves to the 120 degree position. then if I hit either directional buttons it will move to the 90 degree position. After that, I get no response from the servo. I don't know if this is from my poor code writing skills or the noise. I figure I can hook up an LM7805 with some caps to filter it out, however I don't know if that will do anything if it's because of my code as AWOL has claimed above.
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