Overdue Update

Today is payday. This is fantastic for a number of reasons, I haven't updated my blog (or the associated robot) in about six weeks because I've changed jobs and been waiting for paydays to line up. I am going to grab some decent wheels either today or on the weekend and begin really tooling around properly with the thing. I've got a couple of mates tracking my progress (they are insisting on a robot butler, a long running dream I think).

On the weekend the plan is to actually get the motor and wheels fitted and solve this gear problem. When I say I've done nothing on the robot in six weeks I'm neglecting that I go into the laundry (where it currently lives in a pile) pick it up, stare puzzled at the motor and then leave it alone because any thoughts that pop into my head cost money I didn't have. Well it's on like donkey kong now.

Stay tuned :-)

Work begins in earnest

My wife has to go to an all day team bonding session at her law firm today so the toys came out, although I did solve a problem she raised when I started out on this caper in her absence. I picked up a packet of six rather strong magnets at Jaycar last weekend and spent a couple of hours on the robot just now starting by supergluing the magnets out the front of the chasis so that any of her earrings that have dropped off the coffee table onto the floor are spared. My next door neighbor may well think I am a nutcase because he seemed to spend a lot of time just now taking out the rubbish; I imagine so he could figure out why I was gluing magnets to the front of a floorsweeper head and taking photos of it with a self satisified grin on my face.

I also used the cordless drill I grabbed the other week and put some holes in the back of the thing and mounted a power switch and power light as well as mounting the battery pack on the top (it's far too big go inside the chasis, I may wind up mounting a lot of stuff on top for this reason). So I am underway officially. I tooled around with the motor I got and how I will make it actually drive the thing forward. It has a worm-gear that came with it, I may need to actually make some sort of gearbox for it because it's quite powerful (good thing) but much, much to fast; and to think I bought one that said low speed and high torque. I can't imagine what the hell sort of speed the fast one delivers, because it threw the gear from one end of a makeshift axel (coathanger - wirecutters) where it wasn't fixed but was sitting, to the other. I need to figure out a way of slowing it down.

I has a pic programmer and two chassies.

So the pic programmer arrived from Bulgaria today, I have absolutley no idea what I am doing.
I downloaded a program called WinPic. I am able to connect the pic, and verify it and stuff, but now what to do? Learn how to program the thing I guess.

I thought the big problem with this was going to be that I intended to program the pic using a USB-RS232 converter and everything I read about them told me not to - but it seems to work just apples. The problem I neglected to address (and I imagine everyone has this when they program one of these for the first time) is I actually don't know how to program microcontrollers. Not even a little bit. Details huh. There's plenty of websites out there on how tho, but this is going to take longer than I thought if there keeps being parts of it that I actually have no idea how to do.

My Frankston carpet sweeper arrived as well, a few days after I went and bought one from Bunnings, I am a little annoyed that both of them aren't built the way I thought they'd be.
They have two flaps underneath them rather than a solid base which sorta flick upwards to hold the dust. I am putting some thought this week into how to actually build a solid base - I don't know which of the wood one or the plastic one I am going to use - the wood one is bigger but significantly heavier. I'd prefer to use the plastic one but it'll be tricky to mount all this junk in it and still have room for dust.

Chasis

I won this on eBay earlier today, it's a carpet sweeper just like I need but I have a little concern that it IS made of wood. Should be ok, a little heavier but generally speaking I assume it is going to be somewhat easier to work with. Looking at a photo of the underside it has four wheels that are fixed in position, so I don't know how I am going to play this, I may wind up attaching new wheels to the side. I also picked up 6 infrared LEDs to project infrared in front of the thing and four IR transistors to pick up the bouncing infrared off an obstacle, at least that is the plan. This thing will arrive in a few days from Frankston, Victoria (WTF is someone in Frankston Victoria doing selling (just the head of) a carpet from the 1950s on eBay?). The PIC programmer I bought (for $17!!! w00t!![+7p/h]) will take longer because it's coming from Bulgaria. I might tool with the infrared leds tonight and see how they work, I'll rig the emitters and see if I can't make a light light-up connected to a receiver - good to test range too.

First parts purchased

Went and brought some bits and pieces today, some of the bits that I know I'll need but not anything I was unsure about. My current thinking is to use a floor sweeper (box on a stick with a rotary brush in it powered by the force of pushing it along, my wife's idea) and put a drive motor in it and use a second motor to spin the brushes. Further I need the thing to not drive into walls or obstacles so a couple of proximity sensors (either ultrasonic which I've seen online or infrared like the ones they use in parking sensors), likely on each of the front corners and a PIC controller to make decisions about if it gets close to something on the sensor, to trigger some sort of steering mechanism.

So far the bits purchased today were;

• PIC16F628A microcontroller and a PCB socket for it
  
• A switch to power it on :-)
• Two LED lights, one red to indicate it's found an obstacle and steering, and a green power light
• A motor, 12v to drive the wheels
• A worm gear
• A breadboard
• An 8x AA battery holder so I can power the 12v motor with some wires
  
• A plastic hobby box to mount parts in, inside the floor sweeper to protect them
  

I also got a little cordless hobby drill for mounting things, I am super excited :-D Now I just need to find a floor sweeper :-(

Starting the robot

Ok,
I hate the fact that my floor at home is messy but I also dislike vaccuming, it's not that the task is arduous but more that I don't have the attention span to vaccum an entire loungeroom without getting bored; particularly frustrating is getting the shits at the fact that the power cord on my vaccum usually gets accidently pulled out of the wall while I am vaccuming. The solution, I believe, is clear. What I need is a robot to vaccum my house for me.

You can buy them, Roomba and the like but they aren't without their problems - without doing something so nasty as accusing anyone who has spent $600 on this a f****ing idiot I'll be satisfied with saying that Roombas have problems such as;

1. The "virtual wall" feature that they use to stop them going into a proscribed area uses infrared which means they get freaked out in bright sunlight or other scenarios where lots of infrared is used.

2. They have stupid features that nobody wants to use, including "max clean" where you can make the thing focus on a particular area of the floor.

3. $600

So the obvious answer to the problem is to make one.