how do i connect all this??

hi fellas…

look im new in arduino, ad i see is perfect for my project, but id like to know if its possible to connect a lcd display, a numeric pad, and also one servo motor, wich board is suitable for this, arduino uno or i have to use a mega board?? :o :o :o

Not without some extra hardware (such as shift registers); if you went with a serial LCD (or possibly even 4-bit mode, if we are talking a character LCD) it could be done.

Past the hardware, you haven't described the application - you might be able to get the hardware to fit, but maybe the software is more complex (though I doubt it, but it is something to consider).

The keypad can be done with an analog port too, if it hasn't too many keys.

Yes, what you want is possible, but a lot depends on what components you get. And sometimes it's cheaper to get a simple keypad or LCD and a multiplexer or a serial-to-parallel register.


I think it is possible. depending on what size keypad you have.

An LCD display in 4 bit mode uses 6 digital pins, check this:

A 3 by 4 (12 key) matrix keypad uses 7 digital pins:

Servo lib is here:

if you use the analog pins as digital pins (which is possible) you should have enough pins to do it.

Don't use digital pins 0 and 1 since they are used for the serial communication.

ok... the whole thing has this funcion.. pull a string to get some tension about 70pounds max or 50 min... so what i want is to select the tension i need from the pad, it will be displayed on the screen and then the servo will do the work to make the tension on the string....

my frist problem is hardware i mean to connect all this in one board, the software well i know it will be complex but for now i have to solve the hardware part

I'm not sure you can get that kind of pull from a servo.

As for hooking everything up, go step by step.

first hook up the LCD display and make it show some data.

then hook up the keypad and learn how to read a number from it.

then display that number on the lcd.

Then implement the servo.

Always make sure you have everything in one step working before you move on to the next step.

the software well i know it will be complex

No that is the simple bit. Getting the hardware, both mechanical and electronic is going to be 90% of the project.

well i think you are right, it would be better if i use a stepper instead of a servo right… but i dont know if i cant get such a strong stepper… probably id have to use some gear combination to get the output tension i need.

but i dont know if i cant get such a strong stepper

Yes you can get some quite powerful motors. Just calculate how much torque you need. I suspect it is in the range of most medium size motors.

ive been looking for steppers and servos and ive only seen small ones. from 2.5kg/cm to 7.5kg/cm... i dont think that wolud be powerful enough...

and if you think that software is not complex??? even touhg im not like very good programming so i think it would hard to me jejeje.....

for now i got the 2x16 lcd display and the numeric pad....

whole lotta motors here ...

maybe you can find one with the oomph you want.

There's a lot here as well:-

You can easily get a motor to snap your wire. The hard part is getting the shaft coupled correctly.

well the shaft is not that difficult.... i can use an cnc to make it work..

i can use an cnc to make it work..

I don't understand what you mean. When I built my CNC controller I found it difficult to stop the shaft coupler being the weakest link in the motor / coupler / load chain. I used two screws and still it slipped under a large load. It would have been better if I could have put a flat on the motor shaft. Is that what you meant?

Hello All,

I have the above board with the ATMEGA 328 processor. I am trying to upload a simple LED blink program from my MAC computer to this board and I am unable to do so. I am getting the following errors:

avrdude: stk500_recv(): programmer is not responding avrdude: stk500_recv(): programmer is not responding

Also this board is connected via USB to the computer but there is no such option when you go to Tools , it has only dev/tty/PDA/bluetooth or dev/tty/modem

thanks, any help would be much appreciated

Sam buddy. You are WAY in the wrong place dude. Don't hijack someone's thread. Go post your question here.

Depending on how precise you need I think your going to also need a tension sensor. Servos respond to position. Motors respond with speed or torque depending on type and drive setup.

Make sure the motor you get can run stalled for extended amounts of time. Also make sure it has the required output at stall.

you code will read the input from your sensor and compare it to your entered requirement. I am thinking a PWM output feeding a transistor and a DC motor may work well for your needs.

I think your going to also need a tension sensor

well it seen right... but i u could tell me witch sensor to use i dont know about sensors, and if its possible well the more precise its best.....

what i was trying to figure out was positions to the servo, depending on the tension i need the servo could move to some position, but seen a lot more useful and precise to use a sensor..