Max7219 with eight 7segment (0.5 inch height) not bright

[tobb]

Hi .. I use max 7219 with 8 digit 7segment. each segment is about 0.5 inch height. I try serveral value of Rset and use intensity at 31/32 duty cycle. It still dose not bright enough. If i use direct connect R 470 Ohm to the segment it very bright. I connect the circuit follow the datasheet. I wonder what i done worng ?? Or max7219 it self can not give a bright light??

 

[mgajo]

Hi
You can use external driver for higer
current rate.Take a look at data sheet
for applications also internet search
for applications

 

[mayaka2004]

the answer is in the ground system
make sure you use 1 resistor 470R on one wire from the display common

and this way dont distribute the load over the res more over the led as current

straight connect
com has the single res... ok.. 8)