[SOLVED] Newbie - General question on LCD's, 7 segment LED's, timers

Hi all

I am a newbie on this site. Have not played around with electronics in about 20 years. Working on a project with 24 hour programmable timer. Just need some info on somethings. Some questions are real silly so please be patient.

How do lcd displays get customised to show unique icons. For example I want a smiley face and a sad face or are these programmed in via a interface.

The project Im working on requires a display to show temperature and also current time and other values. Should I use LCD or use 7 segement LED. Which is easier.

The circuit will require a programmable timer. Can you point me in the right direction to find circuit diagrams or information.

What software is out there that is good for designing and testing circuits so before i build my prototype I know that it works to a point.

Thanks in advance

LCDs get customized during their manufacture. As a starter I would use seven segment LEDs. When you say "programmable timer", is this a timer that is programmed in use (oven timer) or some special sequence timer that is programed by you.
Frank

LCDs are easier to use. A 7-segment LED display can't do a smiley face or much of anything else other than numerals and a decimal point.

Hi guys thanks for the response

Hi Chuckey

Basically its like a timer you would buy to plug into a wall socket to switch on lights from Monday to Sunday at different time intervals. It has an on state and off state for every day of the week or you can set the whole week with one on state and one off state. I want to use this type of timer in my project. The display on the other hand I would like to create my own. It does not only display the time so if I use 7 segement then I need them for the time and then some more for the temperature display. So I was thinking of using standard LEDs to represent the days and other statuses if I use 7 segment.

I would however prefer to use n LCD display then I can have all the info on one screen instead of using multiple 7 segements and normal LEDs to show statuses. If I do use seven segment will I be able to change it later to an LCD or will this have a major effect on the board layout. See image below as to the different designs.

Hi KJ6EAD

I know you can not have custom icons on 7 segement, what I am trying to figure out would be how to customize or programm an LCD display to get what you want or should I just use seven segement and normal LED's for other statuses. As you can see in the images below what I want to do



I tried to upload pics but it will not let me cause I have only one post and need a minimum of 2.

But here are the links

obrazki.elektroda.pl/23_1294296782.gif

obrazki.elektroda.pl/8_1294296782.gif

Thanks guys

That looks like a programmable thermostat display. You can probably use a 4 or more line LCD display. This is the most commonly used type of display for small projects: HD44780 Character LCD - Wikipedia, the free encyclopedia. You should look for display information specific to the microcontroller you intend to use.

KJ6EAD said:

That looks like a programmable thermostat display. You can probably use a 4 or more line LCD display. This is the most commonly used type of display for small projects: HD44780 Character LCD - Wikipedia, the free encyclopedia. You should look for display information specific to the microcontroller you intend to use.

Click to expand...

Hi


I have still not decided which microcontroller to use. I think maybe the best way to go is with 7 segement LED's as its going to be easier and faster to to get up and running. I a still struggling to find a timer circuit diagram for the type of timer i would like to use.

If you are using a microcontroller then you programe in your timer function in software. For instance you have 4 buttons, "adjust timer", "set on time"," set off time", "store". You will need say 7 + 4 = 11 outputs for the display, plus extra ones for buzzers etc.
So now you write a cyclic programe , which is timed to go around once a second. one bit increments the seven seg display, another pokes this pattern to first display unit. then drives the second, third and forth digit. the programme then checks the "adjust timer" button, flashes the "on time", then displays the stored on time, then looks at buttons to increment the stored time.. . .
Frank

I have never worked with microcontrollers. So they are new to me. I do come from a programming (C#, VB, Javascript) and a electronics background so I figured out with some googling that you can program quite a bit of code into a microcontroller according to its memory capacity, however I am not sure how the pinouts work. I know that you can tell the MC which pinouts are inputs and which are outputs. I looked for tutorials but none of them actually start at the beginning and explain how the whole process works.

Do you have a good link where I can get a basic tutorial of a MC explaining in detail how everything works from pinouts right through to programming? I'am not sure which microcontroller to use. I have been reading up about 8051 microcontrollers and they seem to be used a lot with 7 segement displays. Once I can find the above information out I will know how many microcontrollers I need as there are quite a few triggers I need to implement and data information I need to return to the microcontroller for example temperature probe readings.

Tell me if this sounds correct or is there another way
The project I am working on has to seperate units eg Master/ Slave. For argument sake lets say the slave is the controller which gets all the information from scensors and on / off state of components for example relays. This information is passed to the master controller which is the display. So thinking logically I would need 2 microcontrollers on for each controller. They would pass the information between each other.

So from the Master controller which has a timer programmed in will send a trigger to the slave controller to tell it to turn a relay on. Same with the scensor probe. the slave controller will read the scensors reading and pass it back to update the master controller and the master controller will update the 7 segement display panel

I am so excited returning to my favourite hobby after 20 years. Thanks for all the current and future help

Microchip makes the PIC chips: Microchip Technology Inc. is a Leading Provider of Microcontroller and Analog Semiconductors, providing low-risk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide.. Parallax has a variety of higher level products: **broken link removed**. There are tutorial Powerpoint presentations on the Parallax website.

I looked at the pic microcontrollers and it looks like they are all surface mount controllers. I dont really have the facilities to play with surface mount. Unless I looked incorrectly. Can you give me a specific pic microcontroller that I could use. Thanks

Ask on the microcontroller section of the forum.