Stopwatch with Pause/Lap 6 digit 7 seg LED. HELP! (from old forum)

The original Topic can be found here:,8877.0.html on the old forum.

There we go, back in business. So, were you able to get the TPIC6B595 to drive a 7-segment display using one of these methods?

Not yet Robert.. the post man/woman has just been and delivered 8 x Common Anode digits. These are the small ones so I can concentrate in getting them working first. I have 6 for the time and 2 for the laps.

I will report back later when I get a chance to wire a couple up along with the extra code for the lap counter. :)

I started with the first one and got it all wired ok using the same configuration as before which was handy. :slight_smile: then I added another in series which didn’t work at first until I connected the SRCK and the RCK to the second digit as well as the SERIN/SEROUT.
While I was wiring the third digit I managed to set my Arduino down on top of a pair of scissors which were on my desk… now, nothing works. =(…
After checking the wires and changing the digit, shift register and changing my USB cable with one connected to the other computer I have decided I need another Arduino! (Already ordered!)
While I’m waiting for it to come I will get the rest of the digits wired up.

Hi Robert, sorry for not being on with updates.. I've been flat out the past 2 weeks including a trip to England for 5 days!! Lol. I have got some backing board to mount the numbers on instead of plywood (too heavy). Still looking for a good battery source and trying to decide if it should be internal or external??? Example: Would this battery suit, you mentioned about the power dropping bellow 11.?? something? Well, my new Arduino Uno arrived and as suspected I had blown the other one! :astonished: Lesson learnt! I got everything wired up and all is good. I even managed to successfully wire up the 'G' line for the dimmer and have it working when the pause button is pressed it goes to full brightness. I need to do a little more experimenting but I think the memory saves differently each time depending on weather the time is reset from running or pause mode.???? Need to do some tests and write things down. Other than the above I need to add a clear memory button and it would be good if memory down didn't go below lap1.. or the memory up didn't go above 99. Then I need to add the lap counter to the memory.. should be easy enough.. I will keep you posted of all progress. :)

Hi Robert, the following code is where the problem lay. I managed to write a memory clear but was still getting erratic saves?? the code below in ‘memory write’ didn’t have the ‘copy_’ included for the last digit and was messing up every time it saved anything over 10 mins.
All working now. For some reason I only ordered 7 shift registers and not 8??? :~ so I need to order another so I can get the lap counter running.
I also managed to disable the memory down if it was below address 10.
if (EEPROM_address < 10){
EEPROM_reading_down = 0;
That stopped it showing weird segment light up!? I may also putting a lap total read of 64 lap recalls. 8 digits x 64 = address 512. Although I might stop this at 60 laps.


case 6: // tens_minutes
//Serial.print ("Writing tens_minutes to “);
//Serial.print (EEPROM_address, DEC);
//Serial.print (” ");
//Serial.println (copy_tens_minutes, DEC);
EEPROM.write (EEPROM_address, copy_tens_minutes);
byte_to_write = 1; // reset for next group
EEPROM_address = EEPROM_address+1; // increment for next group
if (EEPROM_address == 516){
EEPROM_address = 0;