-- Read description for schematic and software
Is a display formed by 7 rows and 24 columns of LEDs. I'm using a PIC16F876 programmed by me in assembly. With 3 buttons you can set the word to show selecting letters and numbers. | È un display formato da 7 righe e 24 colonne di LED. Ho usato un PIC16F876 programmato da me in assembly. Con 3 pulsanti è possibile impostare la parola da mostrare selezionando lettere e numeri.
----Update----
I've also made a C library for this display (this is not the code running on the video, library will just interface with the display)
www.dropbox.com/s/h6mozijjw6e...
www.dropbox.com/s/dgo6wsvltgd...
Simple example that will print "Hello":
void main(void) {
LD_Init();
LD_PrintMode(0);
LD_Clear();
LD_Print("Hello"); }
You will also need to setup an interrupt that constantly refreshes the display: (in this case i'm using a 16mhz osc)
void interrupt refresh(void) {
LD_Refresh();
TMR0 = 100;
T0IF = 0; }
If you want to scroll the text you will also need to setup your text length with the LD_SetTextLenght function so that text will scroll only until your limit and not until the maximum text size.
----Update----
-Pressing the right button during the scrolling, now you can set the scrolling speed.
Circuit schematic: www.dropbox.com/s/srn4plpx1bi...
Program code: www.dropbox.com/s/nlfvbn1g6cq...
Components used:
- 1x PIC16F876 (20Mhz)
- 1x 16Mhz Crystal
- 2x 22pF capacitors.
- 32x Transistors BC547c
- 168x red LED (3mm)
- 24x 100Ω resistors
- 32x 1KΩ resistors
- 3x 10KΩ resistors
- 3x buttons
The program is commented in italian so if you have any question you can ask me.
Unfortunatly there are still some troubles when you write something because some times it skip 2 letters instead of 1, you can go 1 block back pressing fast 2 times the central button.