Search results

About three years ago, after becoming disgusted with the state of USB-to-serial converters*, I bit the bullet and bought a used, refurbished Dell Latitude C610 on eBay for not a lot of bucks. It had a dedicated serial port, so it was good for my Picaxe, PIC, and Arduino work. I spent a few...

Howdy, Folks, I've just released a freeware Win XP/Vista program that generates and prints codewheel images that you can use to build homebrew optical encoders. I've included one wheel type that's of particular interest to folks here who are experimenting with robotics, motor positioning and...

Howdy, Folks, I've just released a freeware Win XP/Vista program that generates and prints codewheel images that you can use to build homebrew optical encoders. I've included one wheel type that's of particular interest to folks here who are experimenting with robotics, motor positioning and...

The Problem with Picaxe BASIC When writing a large microcontroller program, it's very important that you write your code as clearly as possible. You should be able to figure out, without a great deal of effort, exactly what it's supposed to do, and precisely how it's supposed to do it. If...

I'm designing a system to control an Analog Devices AD9851 DDS chip from a 28X1 A.0. The 9851 requires 5 bytes transmitted serially and sequentially, clocked by the rising edge of the clock pulse. It doesn't require a chip select, and it sends no data to the 28X1. (I need two other leads...

On 15 May, 2007, kranenborg opened a thread discussing the design of a wideband superhet receiver. His goal is (I'm going to address the following comments directly to Jurjen.) Jurjen, I've been down that road a number of times over the years, to varying degrees. In every case, I've found...

Sorry in advance for the off-topic post. This isn't a Picaxe project (or at least I don't think it is...) But it's so impressive that I just had to share. "David L. Jones" posted, in sci.electronics.design, this Youtube link of a video showing the performance of Boston Dynamics' "Big Dog"...

When folks need more I/O, the most common solution seems to be the 74xx595 shift register. For applications that need to drive a lot of LEDs, the MAX7219 is often the chip of choice. I might have found something better - the NXP (and TI) PCA9555 I/O expander. This chip provides 16...

I've been brushing up on my calc and diff eq. I found a superb free eBook: Calculus by MIT Prof. Gilbert Strang. Strang presents his information by first stressing and clearly explaining fundamental concepts, then, if possible, relating said concepts to real-world situations. He carefully...

Data Sheet While mousing around on the Mouser site, I stumbled across this LDO 5 volt regulator that, in a 3-lead TO220 package, appears to be a pin-compatible 7805 replacement,. It has less than 1/2 volt dropout vs approx 2 volts for the 7805. It doesn't seem to require the large output...

Below is a little test routine that I wrote for someone having problems with the DS1302 real time clock chip I specified for another project. He has an 08M on hand, so we thought if he could get the DS1302 running on the 08M, independently of the other processor, it would tell us where to look...

I bought a cheap scope on eBay five or six years ago. At that time, the Tektronix 2235 (which I bought) was "THE" bargain scope. There were a bunch of them, all going for very good prices. 100 MHz, dual channel. Built like a tank. That scope has been a real workhorse for me. It's been a...

I was curious about loop termination test time and someone in here was curious about ADC timing recently. I set up an 18X, running at 8 MHz, and measured loop timing under different conditons using my oscilloscope. In each loop, I included a toggle 0 instruction. I connected my 'scope to Out0...

Just on a whim, I picked up a couple of ultrasonic transducers recently. They're supposed to operate near 24 kHz, which is well within the range of a Picaxe's PWM output. I don't play with robotics and have no real need for a rangefinder. Don't know what I'd do with one if I built it. I've...

Someone just gave me an old 3 1/2 inch plastic floppy disk box. He asked me if I had any use for it and, just as I was about to say that I haven't used floppies in years and I couldn't use it, I realized that it was the perfect size to house a small project. I said "thank you!" If you have...

In a one of the two recent threads dealing with the design of a speed controller, I attempted a design of a Voltage-Frequency speed controller that might work properly with single phase shaded pole induction motors. I published the schematic on my web page and solicited advice and discussion...

A while back, someone in here was looking for a good C language book. Unfortunately, I can't find that thread right now. Someone mentioned Kernighan & Richie. I'd stay away from that one. K&R isn't much more than a C language specification. Tough to learn from. (I tried, and...

I posted this in another thread, but it seems to have gotten lost in the noise. A timely solution is of some importance to me, so I'm posting this message (and followup test info) in its own thread. ======== Say, Technical, while I have your ear, I'm having some problems with an ambitious...

It wouldn't let me peek the PORTB register. Thanks, Tom oops... answering my own question.. "readoutputs." I knew it was in the manual somewhere, but I was unable to find it. Sorry. Edited by - Tom2000 on 03/07/2007 10:50:09 Edited by - Tom2000 on 03/07/2007 11:58:53

Min doesn't work in the sim or in hardware: <code><pre><font size=2 face='Courier'> Main: b0 = 2 for b1 = 1 to 3 b0 = b0 - 1 MIN 0 next ; At loop exit, b0 = 255 end </font></pre></code>