I'm building an autonomous robot for my second year mechanical engineering design course, which is going to be controlled by an Arduino. We want to have two motors which will be controlled from an L298N Motor Module that we bought at the local electronics shop. However I can't seem to be able to find this specific module online, and I have no idea what each terminal does. I've found other modules online such as Arduino robot kit – Motor Control – Ad Hoc Node but I can't find the one I have. I would really appreciate it if anyone here could offer some guidance on how to use this.
The connectors label all the control signals, the datasheet for the L298N will
explain them. However the jumpers (I think they are jumpers in yellow) probably
override some of the signals - a multimeter with a continuity-test mode (bleeps for
short circuit) will help you track down how things are wired up if the PCB traces are
hard to follow).
MAS3:
See the highlighted area's.
The larger area has for sure severe damage, traces and diodes are burnt.
The smaller ares are questionable.
Could that be just be from the camera flash? Under normal light it doesn't look shiny like that.
MarkT:
The connectors label all the control signals, the datasheet for the L298N will
explain them. However the jumpers (I think they are jumpers in yellow) probably
override some of the signals - a multimeter with a continuity-test mode (bleeps for
short circuit) will help you track down how things are wired up if the PCB traces are
hard to follow).
Thanks, that makes sense. So why is GND and 5V there twice?
cbhatla:
Could that be just be from the camera flash? Under normal light it doesn't look shiny like that.
I guess it could.
Do those diodes look like they are black, or are they an other color ?
They should look exactly the same as the ones at the other side.
I got everything running, but I'm still not sure what the 5V pins are for. I have pins IN1, IN2, IN3, IN4, ENA, and ENB connected to the Arduino, and I have VCC and GND connected to a 6V battery pack. Should I still be using the 5V pins for something? This video makes it seem like I should connect it to 5V on the Arduino to power the H bridge. L298 Motor Control | Arduino Tutorial - YouTube
According to the schematics for the board CrossRoads found, you should be OK.
The 5 volts are all labeled the same, which should mean they are connected.
So you do not need to connect to Arduino's 5 volt supply if you use some other supply.
But still you should be aware of something quite important.
That is about the regulator on your board (still assuming that you have that board), and the voltage you are supplying it.
You are supplying 6 volts and this needs to be converted to 5 volts, so a difference of 1 volt.
The datasheet of the 78M05 tells about the dropout voltage of 2 volts on page 2.
This means that the minimum difference between input and output needs to be larger than 2 volts for the regulator to provide a stable 5 volts.
Are you able to supply 7.5 or 9 volts instead and would your motor be OK with that ?
MAS3:
According to the schematics for the board CrossRoads found, you should be OK.
The 5 volts are all labeled the same, which should mean they are connected.
So you do not need to connect to Arduino's 5 volt supply if you use some other supply.
But still you should be aware of something quite important.
That is about the regulator on your board (still assuming that you have that board), and the voltage you are supplying it.
You are supplying 6 volts and this needs to be converted to 5 volts, so a difference of 1 volt.
The datasheet of the 78M05 tells about the dropout voltage of 2 volts on page 2.
This means that the minimum difference between input and output needs to be larger than 2 volts for the regulator to provide a stable 5 volts.
Are you able to supply 7.5 or 9 volts instead and would your motor be OK with that ?
The motors are 4.5 V, but I don't know how high they can go. It also specifies that the maximum power is attained at 2.5 A, so that could be a problem too if the L298 can only supply 2A.
Be very careful when assuming current related things.
(Not saying you did that)
If a datasheet tells you a part is able to supply 2 A, that doesn't mean there will never be more than these 2 Amperes flowing.
But if this happens, the part will suffer and in time it will be destroyed.
A L298 has no current limit circuitry, you have to create that yourself.
Connecting a 2.5 A motor to that L298 will be troublesome, the 2 Amperes is mentioned as absolute maximum.
Then remember part of the L298 is a set of transistors.
There will be a voltage drop.
So not all the voltage you put in it, will come out of it
I'm not sure how large this drop will be, as there is no mention about what kind of transistors are used.
In case of a single transistor per output, a set will have approximately have 1.5 volts drop.
In case of a darlington, there will be some 3 volts drop per set.
To be sure about that, measure the voltage drop at the motor terminals (and compare it to the measured supply voltage).
