I got to work on wiring up the circuit that will be used - the most time consuming part was simply soldering some wire so it touches both leads (twice) on the stereo socket, but I think I got that part done correctly.

After wiring up the circuit, I ran a voltage test to make sure the voltage regulator was working, and one of the photos shows the 5v clearly.

There is an error in the book (verified by the errata page) with a resistor shown at the bottom of the schematic - ignore it... no resistor goes there.

Up next - typing up the code and then uploading it to the 08M.

Note: You may have noticed in the last photo a clear box of jumper wires. I purchased a box of 150+ pieces for about $10 at a nearby electronics store and I love these things - should have bought a box at the beginning. You can see in the other two photos that I've relied heavily on these pre-cut and pre-stripped wires, ignoring any sense of style when it comes to color.

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Before you get too far into this experiment, you must make certain to install the special USB cable driver on your computer. The USB cable fools the computer into thinking it's talking to the Picaxe chip with an old serial connection (versus actual USB).

The instructions for doing this can be found on an included PDF file in the ZIP file you download, but I didn't have as easy a time installing it as the instructions suggest, so I wanted to walk through this in case there are others who encounter this issue. (Specifically, the screenshots in the PDF do NOT match what is seen on a Vista computer - they do include Windows 7 steps but my limited memory of using XP has me thinking the screenshots also DO NOT match the XP operating system - please feel free to correct me if you find the PDF is correct for XP.)

First, you need to be aware that I'm installing the driver on a Window Vista operating system, so these instructions may not match exactly with your OS... but I think you'll be able to get the basic idea of how to get around any hiccups you encounter.

The first thing you'll do (after downloading the driver - see previous post) is plug in the USB cable. My Vista laptop automatically detected it as seen in the first screen capture I'm including here. As you can see, it recognizes the cable as an AXE027 PICAXE USB device. But whereas the instructions show a nice little pop-up window that asks you to specify the location of the files, I never got this - I got an error message saying "Device Driver Could Not Be Found" and my only option was to click OK. So... it's off to the Device Manager (from a previous life as an IT consultant, I know my way around just enough to be dangerous and figure things out...)

Open Device Manager by clicking Start, and then right-clicking on Computer and choose Properties. Click on the Device Manager option in the left column of the screen. As you can see in my 2nd screenshot, there's an exclamation point next to the device telling me there's a problem.

Next, I right click the AXE027 PICAXE USB device and choose Properties. On the window that appears, I click the "Update Driver" button and a screen appears like the one in the 3rd screenshot.

Click the Browse button and find the AXE027 folder that you unzipped from the driver download. In the screen capture, click on the axe027 folder and click OK.

If everything goes as planned, you should get a screen like the 4th screenshot tellign you the driver installed correctly.

Click the Close button and if you go back and look at the Device Manager screen, you should see that the device no longer has the little exclamation point next to it like my final screenshot here.


And that's it... for the driver install. Next, I'll install the Programming Editor software and get the circuit wired up.

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Before I get started with the circuit on page 299, I need to download and install the appropriate software and driver. The instructions for doing this are clearly explained on pages 296 and 297. I'm running Vista on my laptop, but be sure you click on the driver download that's appropriate for your operating system (Windows, Mac, and Unix all have links).

The 60MB Picaxe software is downloading right now, but when it's done, I'll first install the driver (while the USB cable is plugged in) and then the software.

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I spent a bit of time rewiring the entire circuit for Experiment 32... taking one of my readers suggestions that the protoboard could have a bad insertion area, I moved all the wires to new locations. I then replaced the 555 chip with a new one and used my multimeter to confirm that the relay was getting higher voltage on the coil when a microswitch was pressed. Finally, as a last ditch effort after these efforts produced no change in results, I swapped out the 47uF capacitor with a 100uF... increasing the size should have increased the length of the pulse, but in this case, I get the same results - the motor reverses only when the microswitch is held down.

Argh.

Okay... so... enough of this. I may choose to come back to it at a later time (things like this really bug me) but for now it's time to move forward and get this book finished. Which leads me up to my next announcement - I've read over Experiment 33 numerous times... lost count, actually. But I've decided I'm done with robots for right now. I understand what Experiment 33 does and how it works, and, more importantly, I understand how all those 555 chips work together.

So... now it's time to get to Experiment 34. I've been looking forward to this for a while as my interest in programmable chips has been growing ever since I saw an Arduino in action controlling a remote control lawn mower (see Make issue #22). But I want to start slow... so I placed the order for all the required hardware for Experiment 34 (and 35) and it all arrived this afternoon (see the picture).

I've got 3 of the 08M PICAXE chips, the special USB cable required, and the small stereo socket. Also included in the box was a handful of resistors and misc required to properly wire up the stereo socket. I need to download and install the software specified and I'm ready to go.

Note: Inside the box, the company also sent a photocopied sheet that included a hand-drawing of the 08M wired up in a special manner, complete with resistors and voltage requirements. I'm including a close-up of that photo here, but it doesn't look complicated at all.

More to come...

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This circuit is still driving me up the wall... I triple-checked all my connections, but I'm fairly certain the connections are done properly as the motor behaves somewhat correctly - it spins forward until a microswitch is pressed and then reverses direction... but only for a split second.

I used my logic probe to check the pulse on pin 3 but I'm honestly not 100% sure what I'm looking for...

One thing I did do that puzzles me - I unplugged the motor as it's quite loud and was making it difficult to hear the relay switching... when I did this and I turn on the power, I don't hear the relay doing anything, but when I press a microswitch, I hear the relay click (once) indicating that the coil is getting power and reversing the direction of the motor... but when I release the microswitch, I don't hear the click indicating the relay has switched back... but when I release the power button, I do hear a click. Maybe this is normal, but I'm wondering if somehow the relay is not functioning properly.

I've about decided to move on - I'll puzzle over it later tonight, maybe tomorrow... but if I can't find a solution, I'll move forward as I think I've gotten out of the experiment all I can.

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