Hi Paul. I tried that, it didn`t workHi marzan, no you don't need to change the oscillator timing cap. You do have to enable multiplexing by setting a bit in the saa1024's control register. Data sheet page 6.
Paul
1 & 3, 2 & 4 showing the same.What do you see? 2 digits working ok, the other 2 blank, or all 4 digits on but with unevenly lit segments that don't show the right patterns, or what?
I altered the code so as to get the 2 digits showing seconds and tenths of seconds .What do you see? 2 digits working ok, the other 2 blank, or all 4 digits on but with unevenly lit segments that don't show the right patterns, or what?
Also have you set the digit banking bits in the control register?
Try swapping the mx connections over: do the other pair of segments work then?
Strip back the code to just a test program for the display. I remembered the SAA1064T is what's in a Virgin Media STB so this test program may help. I can't remember what the initialisation bits are but I recall the chip does duplicate digits if not configured right -I altered the code so as to get the 2 digits showing seconds and tenths of seconds .
HI2cSetup I2cMaster, $70, I2cSlow, I2cByte
Hi2cOut $00, ( %00010111 )
Do
...
Hi2cOut $01, ( b1, b2, b3, b4 ) ' Four digits to display
Pause 1000
Loop
I have already tried swapping it out for another one. don`t know whats going on :/ I also did exactly what you said. Just put in values 0,1,2,3 ad got 0,3,0,3So what you're saying is that if you tried to program it to display "1234", you would see "1212"? That does indeed sound like the oscillator isn't running. Have you got a spare saa1064 to try?
Great summary of what has taken weeks for me to piece together. PICAXE TUTORIALS forum spot anyone I would imagine there are a lot of Piacaxe users who would find this the easiest way to get 7 seg displays working, with minimal extra components, On the I2C bus so no extra pins needed (especially if you are already using the I2C bust to interface an RTC)@marzan,
while you are now seeming sorted -ie have faound the current problem, for the SAA1064 you might like to have a look at this thread as well.
http://www.picaxeforum.co.uk/showthread.php?22252-Getting-Started-with-the-SAA1064-i2c-bus-4-Digit-7-Segment-LED-driver-chip
Posted the wrong board here is the circuit diagramI tried to make sense of your photo of the PCB but not sure that I am right. Looking at the looping at the top and bottom for the 4 digits, it appears that you have the cathodes for digits 1 and 3 linked together and for digits 2 and 4 linked together.
Digits 1 and 2 should have common cathodes and likewise digits 3 and 4.
Hmmm.. guess I should have put 10k resistors ???What switches Q4 and Q5 off?
Yer I tried it Pete. Same deal.Have you tried the code example i emailed you some time back to see if its a code problem or a hardware problem.
I well expect a hardware problem.