• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Need help on PIC18F452 LED Scrolling Message using Bluetooth

Not open for further replies.


New Member
-Microcontroller: 18F452
-Display driver: MAX6952
-Communication protocol: Bluetooth
-PREFERRED programming language: C

-Send data (text) to microcontroller using bluetooth
-microcontrolller feeds/processes messages to be displayed by the MAX6952
-message should be scrolling

I am literally starting from scratch. Please, please, anyone who can help me get this project from start to completion....?

Thank you very much! :)


Well-Known Member
what are you using to comunicate via bluetooth? Is it PC/LAPTOP to PIC? or is it PIC to PIC.

What hardware on the pic side are you using for bluetooth transmissions?


New Member

Thanks for the prompt response. :)

I am going to use a bluetooth module which will be connected to the microcontroller, the details of the IC to follow here.... :) I am assuming that the hardware sources would not be an urgent issue right now, since the code itself has not yet been developed.... :( But I would still greatly appreciate all suggestions/ideas on this part of the project.

Meanwhile, my major concern is on how to create a scrolling message even in a simple computer simulation.

Can anyone provide even a very simple scrolling text program in C, please? (Where the input would be from a virtual terminal/keypad/any outside source..)

Thank you so much.... :)


Well-Known Member
Its funny because the scrolling text is the easiest part of this project. I see your using the MAX6952 .. first thing is to get a copy of data sheet;

QuickView - MAX6952 4-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5 x 7 Matrix LED Display Driver

the way this device works is mainly to show steady characters. you can scroll easy if you just change the start of the string for each send like if you have the string HELLO

Send LLO
Send LO
Send O

Now its best to have a buffer. This way you know the length of the strings with a simple loop. Its easy if you simply let the last char in the string be 0x00 this way you have a endpoint. so if you have a buffer of 16 chars aka bytes then you can have a string like

H, E, L, L, O, 0x00,0,0,0,0,0,0,0,0,0,0

and make a loop to determine the len place the len in a var then dipsplay the string to the max6952 from start 0 then start at pos 1 then 2 until you reach the len var,

Hope that makes sense. I cant write the whole code for you tho.


New Member
You are definitely right, it's the easiest part of the code. =))

However, I am talking about storing the message in an array (which you have perfectly explained as buffer), and I am not displaying the contents correctly.

I am using a built-in function of the microcontroller (PIC18F452), which is the RCREG. Thanks for the link of the datasheet.

For the simulation details, I am using Proteus 7 Professional and my compiler is CCS-C. I am using C Language.

Problem is, I could not store the RCREG output correctly into the buffer which is why the MAX6952 could not display the characters properly.

Any ideas on the programming part please?


Well-Known Member
since your using C it should be simple.

How are you getting the characters? Do you have a receive code i can see so i can modify it and show you how its done.


New Member
max 6952 switching

my max 6952 output pins r not switching ... i am trouble shooting since last week but no effect on.. plz tel me what is problem coz of max not switching...
Last edited:
Not open for further replies.

EE World Online Articles