Using max7219 (dot matrix) with Water pump motor Issue.

Hi. In the project, we are using a dot matrix and a mini underwater pump motor. The power supply is used by connecting six AA batteries. (9v) This is not a problem when used as a dot matrix or a submersible motor alone, but when both operate at the same time, a problem occurs. Only the dot matrix is turned off, or both the underwater motor and the dot matrix die. However, no matter how you change the environment, it really works well.

Battery power problem, circuit problem, Arduino operator memory issue I tried to solve for about 3 weeks, but I could not solve it. What is the problem?

Where is the circuit diagram, specs on the dot matrix and motor? Where is the battery pack connected and how are all the devices powered?
As a very general rule, when ever either of two devices work fine alone but do not work together, it usually boils down to a power issue, poor programming notwithstanding.

Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.,148850.0.html then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks... Tom... :slight_smile:

Show us yer code, of the sketches that work, and the combination that doesn’t. Show your schematic. Include the relevent information on components, particularly the power section.