Confusing L298n module problem

Hi, could use a little help with a l298n module problem. The problem is that I have to be touching several parts with skin for it to work. At first I thought that it didn't work and bought another one, that 2 didn't work. Checked motors, power supply, code, everything works fine, wrote the simplest code to simply drive one way didn't work, tested everything on l293d, everything was fine and working, but 298n, nothing. While trying to make it work I touched a few pins (the in and enable pins), it suddenly started working and stopped once I let go. It also worked once I touched uno usb port along with l298 heatsink and some other random combinations with me touching metal parts. It doesn't seem to be one pin, but multiple at the same time and only with skin contact. Checked with both modules( bought from different sources), same result. This is a ridiculous problem. Has anyone encountered this? Should I just try to make my own l298 pcb instead?

You need to make a simple pencil drawing showing exactly how you have everything connected and post a photo of your drawing. See this Simple Image Guide

Also post a link to the datasheet for the specific L298 module you are using.

A very wild guess (very wild) is that you don't have good GND connection to the Arduino


Robin2: A very wild guess (very wild) is that you don't have good GND connection to the Arduino

I don't think that's a wild guess at all: quite reasonable based on the OP's explanation.

I had a similar experience 20 odd years back using a 298 driven off a 297 to control a stepper from a PC parallel printer port.

Noticed that when my bare foot touched the floor, the motor ran. That was completing the ground (literally) from the PC case to the metal box where I had all the bits and pieces, and which was in my hand, thus acting for the wire I had left out.

But OP, for the 293 to work you must have had a ground?