How to Make a Diy pov Cylinder Display

components
$2 for 10 PCBs & $6 for stencil: https://jlcpcb.com

#1#  arduino nano
#2#  li po battery
#3#  leds
#4#   12 volt motor
#5#    printer timing belt
#6#   printer timing belt pulley
#7# fevitite gum
#8#  1k resistor
#9#   22k potentiometer
#10#  26mm  bearing
#11#  cable tie
#12#  potentiometer red knob
#13#   screw terminal
#14#  dot veroboard
#15#  nut and bolt

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Code
int text_ok=0; int a[] = {126, 144, 144, 144, 126}; int b[] = {254, 146, 146, 146, 108}; int c[] = {254, 130, 130, 130, 130}; int d[] = {254, 130, 130, 130, 124}; int e[] = {254, 146, 146, 146, 146}; int f[] = {254, 144, 144, 144, 128}; int g[] = {124, 130, 138, 138, 76}; int h[] = {254, 16, 16, 16, 254}; int i[] = {130, 250, 130}; int j[] = {12, 2, 2, 2, 252}; int k[] = {254, 16, 40, 68, 130}; int l[] = {254, 2, 2, 2, 2}; int m[] = {254, 64, 32, 64, 254}; int n[] = {254, 32, 16, 8, 254}; int o[] = {124, 130, 130, 130, 124}; int p[] = {254, 136, 136, 136, 112}; int q[] = {124, 130, 138, 134, 126}; int r[] = {254, 144, 152, 148, 98}; int s[] = {100, 146, 146, 146, 76}; int t[] = {128, 128, 254, 128, 128}; int u[] = {252, 2, 2, 2, 252}; int v[] = {248, 4, 2, 4, 248}; int w[] = {254, 4, 8, 4, 254}; int x[] = {198, 40, 16, 40, 198}; int y[] = {224, 16, 14, 16, 224}; int z[] = {134, 138, 146, 162, 194}; int eos[] = {0, 3, 2,0}; int excl[] = {0, 250, 0}; int ques[] = {64, 128, 138, 144, 96}; float delayTime=1; //POV clock cariables unsigned long currentMillis, elapsed_loop_counter, previousMillis; unsigned long counter_1, current_count; //Interruption varaibles to count rotation speed //We create 4 variables to store the previous value of the input signal (if LOW or HIGH) byte last_IN_state; //Here we store the previous state on digital pin 13 float one_rot_time=0; //Here we store the full rotation time float time_per_deg=0; //Here we store the time it takes to make one degree rotation void setup() { PCICR |= (1 << PCIE0); //enable PCMSK0 scan PCMSK0 |= (1 << PCINT5); //Enable pin state interruption on pin D13 //Output pins register configuration DDRD |= B11111100; //2 to 7 as output DDRB |= B00011111; //8 to 12 as output DDRB &= B11011111; //13 input PORTD &= B00000011; //2 to 7 LOW PORTB &= B00000000; //8 to 13 LOW } void draw_a_line(int this_line){ int now_line; now_line = this_line; if (now_line>=128){PORTD |= B00100000; now_line-=128;} else {PORTD &= B11011111;} if (now_line>=64) {PORTD |= B01000000; now_line-=64;} else {PORTD &= B10111111;} if (now_line>=32) {PORTD |= B10000000; now_line-=32;} else {PORTD &= B01111111;} if (now_line>=16) {PORTB |= B00000001; now_line-=16;} else {PORTB &= B11111110;} if (now_line>=8) {PORTB |= B00000010; now_line-=8;} else {PORTB &= B11111101;} if (now_line>=4) {PORTB |= B00000100; now_line-=4;} else {PORTB &= B11111011;} if (now_line>=2) {PORTB |= B00001000; now_line-=2;} else {PORTB &= B11110111;} if (now_line>=1) {PORTB |= B00010000; now_line-=1;} else {PORTB &= B11101111;} } void displayChar(char cr, float line_delay){ if (cr == 'a'){for (int i = 0; i <5; i++){draw_a_line(a[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'b'){for (int i = 0; i <5; i++){draw_a_line(b[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'c'){for (int i = 0; i <5; i++){draw_a_line(c[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'd'){for (int i = 0; i <5; i++){draw_a_line(d[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'e'){for (int i = 0; i <5; i++){draw_a_line(e[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'f'){for (int i = 0; i <5; i++){draw_a_line(f[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'g'){for (int i = 0; i <5; i++){draw_a_line(g[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'h'){for (int i = 0; i <5; i++){draw_a_line(h[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'i'){for (int itr = 0; itr <3; itr++){draw_a_line(i[itr]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'j'){for (int i = 0; i <5; i++){draw_a_line(j[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'k'){for (int i = 0; i <5; i++){draw_a_line(k[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'l'){for (int i = 0; i <5; i++){draw_a_line(l[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'm'){for (int i = 0; i <5; i++){draw_a_line(m[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'n'){for (int i = 0; i <5; i++){draw_a_line(n[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'o'){for (int i = 0; i <5; i++){draw_a_line(o[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'p'){for (int i = 0; i <5; i++){draw_a_line(p[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'q'){for (int i = 0; i <5; i++){draw_a_line(q[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'r'){for (int i = 0; i <5; i++){draw_a_line(r[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 's'){for (int i = 0; i <5; i++){draw_a_line(s[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 't'){for (int i = 0; i <5; i++){draw_a_line(t[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'u'){for (int i = 0; i <5; i++){draw_a_line(u[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'v'){for (int i = 0; i <5; i++){draw_a_line(v[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'w'){for (int i = 0; i <5; i++){draw_a_line(w[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'x'){for (int i = 0; i <5; i++){draw_a_line(x[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'y'){for (int i = 0; i <5; i++){draw_a_line(y[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == 'z'){for (int i = 0; i <5; i++){draw_a_line(z[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == '!'){for (int i = 0; i <3; i++){draw_a_line(excl[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == '?'){for (int i = 0; i <5; i++){draw_a_line(ques[i]);delayMicroseconds(line_delay);}draw_a_line(0);} if (cr == '.'){for (int i = 0; i <4; i++){draw_a_line(eos[i]);delayMicroseconds(line_delay);}draw_a_line(0);} delayMicroseconds(line_delay*2); } void displayString(char* s, float line_delay){ for (int i = 0; i<=strlen(s); i++){ displayChar(s[i],line_delay); } } void loop() { currentMillis = micros(); elapsed_loop_counter = currentMillis - previousMillis; delayTime = time_per_deg*3.5; if((elapsed_loop_counter >= time_per_deg*(216)) && (elapsed_loop_counter < time_per_deg*(217)) && text_ok) { displayString("Youtube",delayTime); //delayMicroseconds(delayTime*10); text_ok=0; } } ISR(PCINT0_vect){ //First we take the current count value in micro seconds using the micros() function current_count = micros(); ///////////////////////////////////////Channel 1 if(PINB & B00100000){ if(last_IN_state == 0){ last_IN_state = 1; counter_1 = current_count; } } else if(last_IN_state == 1){ last_IN_state = 0; one_rot_time = current_count - counter_1; time_per_deg = one_rot_time/360.0; previousMillis = micros(); text_ok=1; } }