both the ends +ve i/p and the ive i/p is connected to ground.. so there will be no potential difference b/w them and 0804 works on differential i/p…
and you can use animated LDR as a sensor part..
or fix -ver i/p to gnd and use a preset to vary the +ve i/p voltage…
for LCD check you code just try to print a simple letter A on LCD and check you ckt…