Its a classic SAA 1064 driving four seven segment LEDs by UNO.
I am using the sketches given in this tutorial to check if the PCB we got made is fine : http://tronixstuff.com/2011/07/21/tutorial-arduino-and-the-nxp-saa1064-4-digit-led-display-driver/
My observations: ( The address is 0x70 )
- The Counter sketch works fine.
- The dimming Sketch does not work.
In fact the main problem itself is that irrespective of any change to the dimming bits ( C4,C5,C6) the intensity remains same in the counter sketch.
I am using BC547 transistors and the timing capacitor is marked 272 which is 2.7nF ( of course I have not actually checked if its the actual value )
Any pointers to check as to why the intensity is not variable ? ( The display module has its direct 5V power supply and not from the UNO)