cakesmith handyman posted:

Hello thread, I've a project in mind and wondered if an arduino was the right way to go with it. I want to control Lego contraptions without a PC. Years ago I'd have used the RCX controller I got with a mindstorms kit, but it's very limited (3in/3out) and to program it now would require faffing about with Windows 98 and obsolete patches.

All the sensors and motors are 9v and I'm happy to modify cables to connect one system to the other but before I start is an arduino variant the best thing to start with? Can they drive motors in 2 directions natively or do they need external motor driver boards?

cakesmith handyman posted:

Okay, how about this then:

http://www.sniff.org.uk/2016/03/lego-dacta-control-lab-b.html?m=1

The whatsit about half way down the page is basically a Lego IO rack with H-bridge motor drivers, however it's serial controlled via M-F DB9 null modem cable. Is there any way I could control this with arduino?

cakesmith handyman posted:

Hello thread, I've a project in mind and wondered if an arduino was the right way to go with it. I want to control Lego contraptions without a PC. Years ago I'd have used the RCX controller I got with a mindstorms kit, but it's very limited (3in/3out) and to program it now would require faffing about with Windows 98 and obsolete patches.

All the sensors and motors are 9v and I'm happy to modify cables to connect one system to the other but before I start is an arduino variant the best thing to start with? Can they drive motors in 2 directions natively or do they need external motor driver boards?

cakesmith handyman posted:

Looks like I need those 298 boards for the Lego, though those relay boards look like they can drive 250VAC? I'm sure I can find a few uses for those too.

Hobnob posted:

Also if all you want to do is integer powers of two (for binary bit twiddling) you'll probably be better off using the left and right bit-shift operators << and >> .

coyo7e posted:

A mic with two leads would act as a resistor i believe, so you could probably use something like this http://oomlout.com/a/products/ardx/circ-09/ would probably work if u look up syntax for the mic, and have an LED get brighter or dimmer with room noise.

Wouldn't a 3 prong mic work like a transistor (switch)? That's more complicated by a bit I would think.


http://www.learningaboutelectronics.com/Articles/Arduino-microphone-circuit.php

gonadic io posted:

How does the Zero compare to the MKR zero? It talks about having the same pins (and the data sheets look the same to me), is it literally the same thing except smaller, lighter, and cheaper? Are there any downside to getting it?

gonadic io posted:

How does the Zero compare to the MKR zero? It talks about having the same pins (and the data sheets look the same to me), is it literally the same thing except smaller, lighter, and cheaper? Are there any downside to getting it?

awesomeolion posted:

Platystemon posted:

You need a shared ground.

awesomeolion posted:

New question for y'all. Now that I've got both motors running on batteries I'm trying to control them using an IR sensor. If I have "irrecv.enableIRIn();" in setup then only one motor runs. If I comment it out both motors run. I know that the IR receiver can block but why would it stop only one motor from working?

code:

#include <IRremote.h>

const int RECV_PIN = 6;
const int RIGHT_WHEEL_PIN = 3;
const int LEFT_WHEEL_PIN = 5;

IRrecv irrecv(RECV_PIN);

decode_results results;

void setup()
{
  pinMode(RIGHT_WHEEL_PIN, OUTPUT);
  pinMode(LEFT_WHEEL_PIN, OUTPUT);
  
  irrecv.enableIRIn();
}

void loop() {
  analogWrite(RIGHT_WHEEL_PIN, 250);
  analogWrite(LEFT_WHEEL_PIN, 250);
}

Edit: Wow Fritzing is cool! Here's my current setup:

Splode posted:

I may have found your issue
https://forum.arduino.cc/index.php?topic=93994.0

Your arduino might have run out of hardware timers. Apparently that ir library you're using uses one, and analogWrite uses one too.

cakesmith handyman posted:

I bought one of those Elegoo starter kits and apart from a couple of slightly bent pins (yes I just grabbed some pliers) mechanically it's been fine, however the tutorials & the code & the accompanying schematics and drawings don't always match, which is frustrating when you're trying to learn something & you have to find where they sent you wrong.

Also I did the shift register tutorials and now I cant get the chip off the breadboard and I'm afraid I'll destroy it. Is there a special tool I need? Hell is there a little toolkit anyone could recommend? I don't have anything at this scale,

cakesmith handyman posted:

I bought one of those Elegoo starter kits and apart from a couple of slightly bent pins (yes I just grabbed some pliers) mechanically it's been fine, however the tutorials & the code & the accompanying schematics and drawings don't always match, which is frustrating when you're trying to learn something & you have to find where they sent you wrong.

Also I did the shift register tutorials and now I cant get the chip off the breadboard and I'm afraid I'll destroy it. Is there a special tool I need? Hell is there a little toolkit anyone could recommend? I don't have anything at this scale,

coyo7e posted:

how do you mean they were wrong? Are they like the arduino stuff I got from adafruit where it has a cut-out piece of paper that goes over the breadboard, or something else like you're looking at DCDs and they're not working?

My breadboard cutouts were "correct" but they were a little off-scale or something and anyway after the first two or three you should be picking up enough to do them from eyeball, imho. What's giving you trouble? Share a pic or code or something if possible.

unpacked robinhood posted:

I'm still working on my u8glib editor

Now you can edit a picture in gimp and directly load it in my tool. I've been trying to find efficient ways to store those imported binary images on an 8 bit AVR.
So far there's a rudimentary RLE algorithm.

For example


compresses to a 249 elements long array of 8 bit ints

code:

#define IMG_LENGTH 128
#define RLE_BYTES  249
uint8_t img1[RLE_BYTES] = {
0xFF , 0x00 , 0xB3 , 0x0B , 0x75 , 0x08 , 0x77 , 0x07  ,....}

It works really well as long as the array stays under 255 elements long (because I'm on a 8 bit I guess ?)

What's the proper way to use longer arrays, I think I need several ? My problem is I know mostly gently caress all about C

The display code is this

code:

	uint8_t c=0x00,i,j,x=0,y=0;
	for( i = 0; i < RLE_BYTES; i++ ) {//read image byte array
		for (j=0;j<img1[i];j++){//write current byte to screen
			if(x<IMG_LENGTH-1 ){
				if (c==0x01){u8g_DrawPixel(&u8g,x,y);}
				x++;
			} else {
				x=0;
				y++;
			}
		}
		c=c^0x01;
	}

unpacked robinhood posted:

It works really well as long as the array stays under 255 elements long (because I'm on a 8 bit I guess ?)

What's the proper way to use longer arrays, I think I need several ? My problem is I know mostly gently caress all about C

unpacked robinhood posted:

code:

	uint8_t c=0x00,j,x=0,y=0;
        uint16_t i;
	for( i = 0; i < RLE_BYTES; i++ ) {//read image byte array
...
	}

JawnV6 posted:

You could break it into several arrays, but that's not your problem. This is a fix:

You were declaring the loop index 'i' as a uint8_t. That has a maximum value of 255. When it was incremented from 255, it would wrap to 0, then the comparison to RLE_BYTES would always be true, and I'm guessing you hit an infinite loop there.

Declaring i with a wider width (uint16_t) should fix that issue.

Jamsta posted:

Talking of u8glib, u8g2 is out now:

https://github.com/olikraus/u8g2

Finally supports Arduino on ESP8xxx. Has framebuffers and lots of other cool stuff too.

Now I can upgrade my homemade Arduino lawn trimmer to be WiFi enabled along with it's OLED screen.