got my hands in a old maker made maslow kit but the guy i got it from lost the motor shield i can get a mega off amazon no problem but i cant find the shield anywhere so it all just a paper weight please help if you can.
you can make one with 3 of the L298 motor control boards and a few jumper wires using a Mega off of Amazon. Probably not the cleanest solution, but you can do it for a lot less than the asking price of $150 that they were being sold for if money is of concern. you just have to get the encoder and the motor wires connected correctly for the encoders and motors to work right. I did it.
Do you have a diagram for this process.
I know from the firmware which pins on the mega are mapped to which motors. I went so far as to buy a mega shield perf board to make one of these, but I had a different shield fail, so I soldered the boards directly to the broken board… I call it the franken shield.
Shield:
L298
I went off the schematic for the original shield. The original shield used 2 L298N chips, but with 2 motors on one chip, it tends to overheat and then the motors will randomly stall and try to catch up and the cuts look weird, so I used 3 boards for 3 motors and they are not super expensive. Probably the most challenging part will be getting the right JST-XH 6 pin header wired up correctly to plug the motor cable in. I had planned on doing a write up of the DIY shield with these 3 boards and a perf board, but my janky setup was working and I had other things to do.
Here is the original schematic. the chips are the same as on the red boards linked to amazon, but they were integrated on the maslow shield.
The trick is to set the addressing pins on the mega so it thinks it is connected to a version 1.1 or 1.2 shield and then wire your setup to match that and it will work.
here is the firmware definition code for version 1.2. The mega board pin numbers are the same as defined here:
|//PCB v1.2 Detected||
|---|---|
|||
|//MP1 - Right Motor||
|encoder1A = 20; // INPUT||
|encoder1B = 21; // INPUT||
|in1 = 4; // OUTPUT||
|in2 = 6; // OUTPUT||
|enA = 5; // PWM||
|||
|//MP2 - Z-axis||
|encoder2A = 19; // INPUT||
|encoder2B = 18; // INPUT||
|in3 = 7; // OUTPUT||
|in4 = 9; // OUTPUT||
|enB = 8; // PWM||
|||
|//MP3 - Left Motor||
|encoder3A = 2; // INPUT||
|encoder3B = 3; // INPUT||
|in5 = 11; // OUTPUT||
|in6 = 12; // OUTPUT||
|enC = 10; // PWM||
|||
|//AUX pins||
|aux1 = 17;||
|aux2 = 16;||
|aux3 = 15;||
|aux4 = 14;||
|aux5 = A7;||
|aux6 = A6;||
|||
|aux7 = -1; // unconnected||
|aux8 = -1; // unconnected||
|aux9 = -1; // unconnected||
in1, in1 (motor1), in3, in4 are z axis and in5, in6 are (motor2) but each correspond to in1 and in2 on their specific red board when you connect them.
the address pins on the mega are
* #53-#52 #27-#26 #25-#24 #23-#22
* ------- ------- ------- -------
* 128 64 32 16 8 4 2 1 binary math values. add if value is PU
* GND GND PU PU PU PU GND PU -> rev.0001 PCB v1.0 aka beta release board = 61
* GND GND PU PU PU PU PU GND -> rev.0002 PCB v1.1 = 62
* GND GND PU PU PU PU PU PU -> rev.0003 PCB v1.2
so you tie pins 52 and 53 to ground and put a 5 kΩ resistor to power (PU = pullup) and connect 22,23,24,25,26,27 to it.
While it isn’t much to look at (lots of hot glue to keep the random soldered wires in place, it has been functional for 2 years and cranking out product for me, however I recently sold off that product line and this maslow is coming down. It is for sale on this site as a system, but I’ll part it out if you want the controller:
the only catch with it is that it runs a custom firmware version because the shield doesn’t report as a 1.2, it is a 1.6 board because of the other chips that were on it. I also have a due and a version 1.0 shield for that you could likely use or modify to work with your mega.
The fan above the controller is required in summer time when the router is cutting across the top center and if not air cooled may produce the scalloped edge effects that I don’t like. The LM298N boards need a bit of air flow in higher ambient temperatures (~90+ °F) since this is hanging from the garage ceiling. The fan is from a computer case and kicks on whenever the 12V motor power is switched on.
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Thanks I’m going to see what I can do
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Post back what you end up doing.
How much for that motor shield
That looks pretty good. Where does the 12 V motor power connect to the 3 boards? Seriously. I think you are close.
I’ll send you a perfboard and one of another board variant I have that could help. respond to my personal message and I can get you something sent.
This might be the schematic you seek: