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Managing motors with dual L298N

Hi
I found difficult to find Maslow motorshield in Poland.
Recently i bought and Arduno Mega board and L298n module:

It got 4H bridges separately, and can provide 2A of current.
It`s responding to TTL on 8 digital pins and can run 2 DC and 1 stepper motor.

I will try to create another shield directly for this module.
Can any1 paste a pinout between Arduino Mega, Encoders and H bridges?
Ill share my work on EasyEDA platform.

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you need to drive 3 DC motors (left, right and Z)

there are two types of shields supported (that have different ways of driving
the chip signals)

you may want to look at the thread on the ‘smoke herder’ motor shield, it has
better driver chips than the stock (3A per channel with thermal limiting)

Ok. Im prepared to run 3 DC motors with 3 encoders.
Ive got problem with Maslow standard shield, especially with pinout schematics.
After i get this pinout i will prepare very dangerous files that will contain “Fat” DIY version of maslow shield.

Take a look at the system.cpp from the firmware. The type of shield it detected and the pins assigned accordingly. Line 98-227. You will need to figure how your shield will be recognized, or change the file.

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Ok Gero. There is link to my schematic.
https://easyeda.com/polaski/Maslow-CNC-Shield

I hope its correct. I will try to prepare 1-sided PCB from that.
There is small problem with trace thickness. I was always tryin to prepare 1mm thickness for 1A of current.

Ok. Ive prepared my shield to create PCB.
Let me see Your opinion on this project.
Here are links to EasyEDA
https://easyeda.com/polaski/Maslow-CNC-Shield

How it recognize that is 1.3 version of shield?
I would like to contribute this to community

Sorry I can’t help much, i’m not a programmer in this project. I just knew the file for the pins because i wanted to add a PWM pin to control my spindle speed. Never got it to work.

I think that on the different shields one different pin is connected to ground (pulled low), but i’m not sure.
Line 262 - 285 do the check, but i don’t understand it.

I know that with NO shield on the Mega, GC reports shield 1.2, so maybe that is a safe option to use this pinout.

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Here is another version.
I found Ver pins are attached to pins 22,23,24,25,26,27.
I prepared a board that got this pins free at the moment.
https://easyeda.com/polaski/maslow-cnc-shield-v2

How to use this pins to get 4th version?
There are 6 pins for that.

If i get this figured out today ill will test the board immediately. (3h to prepare prototype)

I’ve created prototype:


I still have floating version pins. How to connect them to get version 4?

I will prepare new prototype basing on version 1.2 pinouts

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https://easyeda.com/polaski/maslow-diy-1-2-shield-for-external-h-drivers
Here is version compatible witch 1.2 shield.
Use it, test it and feel free to abuse it with L298n bridges.

2 Likes

Im about to finish my own “NO EXCAUSES” maslow mill. Made of cheapest materials :stuck_out_tongue:


Im preparing to install shield based on my 1.2 version.

5 Likes

This looks fantastic!

I would be interested to hear your review of that Makita router and if it stays happy and cool during long cuts.

Also, I like how you have attached your ring? Did you bend and drill through a steel dowel? It looks fantastic

Ring is made from very soft steel 12 mm.
I was planing to make somthing like this:


But I went in shop they had metal bender. 8$ for material with bending to ring (it must be soft steel, otherwise it will tear and act like spring).
Then i drilled 4mm holes in places where CNC ring have mounting points.
I don’t have money to buy cnc ring :stuck_out_tongue:

I made few tweaks in my maslow 1.2 shield schema. Added more GND Pins and 1 more 5V out pin.

2 Likes

Nicely done!

I’ve got problem. Every motor test fails. They wont even move(or I’m blind).
Im using A58SW-555B motors 1:290 27RPM witch buildin encoders.


I will try again tomorrow because today, only think ive done is to run GC on old laptop

I run GC on linux witch succes, but still every motor test fails.
I created test programs to set mill plate in middle of board using arduino, so H bridges works fine and moves plate w/o problem.
My bet is that encoder is connected badly. I rotated encoder witch finger and get message that Error Message that Sled is not Keeping Up
Help me understand that.

90% of the time when we get this report, the problem is that the power cord is
plugged into the arduino rather than the motor shield (they have the same plug
and are very close to each other)

David Lang

Arduino takes power from USB. There is separation between shield and external L298N bridges (they share only GND and control pins).


Look at the shematics of my DIY version. There is no connection for external power supply, this connection is placed on board that carry H bridges.
Soo, what i should correct :expressionless:
Shall i add Transoptor separation or somthing?

What is the procedure of motor testing?
Moment… shall i calibrate 1st?

Lets consider all options
I can power arduino mega from power supply and use Mega with ESP8266 if power is the case. I can optically separate USB for TTL communication and use 12V 5amps from power supply to run whole shield+Arduino.

I can power arduino witch 12V via power plug and it still goes through regulator, will I get better result?
It look like default shield works as power shield for arduino. My shield is doing this only for motor controlls, encoders that hangs on long cables dont get much power.