Pro mini not running large code

Hi
Im just making a clock with MAX7219 8x32, DHT11, RTC and two buttons to change and scroll through options. It uses 93% storage and 28% dynamic memory on a clone pro mini. It downloads onto the pro mini but just flashes the display randomly. The programme works perfectly with the Uno and the Mega both clones and genuine ones. The pro minis (I have tried all three that I have) works fine with smaller programmes like an egg timer with lights and a buzzer but not with the clock programme. I have tried using computer power, 9v battery through the raw input and a 9v power supply through breadboard power. Again all work this way with the Uno and Mega boards just not on pro minis.
Am I missing something?? Does the pro mini have power issues when running large programmes??
Thanks

The first glaring hardware difference is the voltage that the Mini operates at: 3.3V. Unlike the Arduino Uno, which has both a 5V and 3.3V regulator on board, the Mini only has one regulator. The Pro Mini 3.3V runs at 8MHz, half the speed of an Arduino Uno. Post a schematic, not a frizzy thing.

@gilshultz

Where do you see 3.3V mentioned?

ProMini exists in two variations; 5V/16MHz and 3.3V/8MHz.

Pro mini 168 ?

hammy:
Pro mini 168 ?

Indeed, I have ordered 'Pro Minis' from the far East and had them supplied with 168s on them.

OK, two official variants and a stack of unofficial variants :wink:

I’m using 5v 16mhz pro minis and I think it is the ATMEGA168 so that could be my problem. Will get a 328p version and see if it makes a difference
Thanks for the help

Yes the 168 variant has less memory

Chatweka01:
I’m using 5v 16mhz pro minis and I think it is the ATMEGA168 so that could be my problem. Will get a 328p version and see if it makes a difference
Thanks for the help

You should be able to read the numbers off the chip if you have a magnifying glass or excellent eyesight. Seems odd that you would not get an error trying to program it as an atmega328 if you actually have the atmega168.

How are you powering the display? There is no way the regulator on a pro mini can supply the needed current.

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