Recent content by CWells

I wonder if someone can point me to a basic tutorial on serial transmission - I've been working on a project for a while, and some background would help me work out some of the problems I'm having. I'm using inverted signals, while tying pins to +5v with a 1K resistor. I set the pins to high...

I'm sending serial signals between several different types of microcontrollers. For some reason, my Picaxes can only understand each other, and nothing else understands the Picaxes. My BS2s have no problem talking to my BX-24s. I'm trying to use 2400 baud, 8 data bits, no parity, one stop bit...

I've been messing with serial communication for a while now...I have to have 2 outputs share an input line, making diode mixing necessary. I have some 1N914 diodes, and I was trying to find out how to orient them, and they seem to pass a logic signal regardless of which way I put it in the...

I've been getting spurious results with a project I'm working on using multiple Picaxe 08M's communicating serially. I need to be able to connect & remove lines while the circuit is running, and the 8M's seem to have a hard time linking up right - sometimes the bytes are in the wrong order, and...

I'm working on a project with two 8M's connected to another uC. I've found that the 8M's are getting powered up through the serial line, which is a problem because I can't reset them now, and they spend all their time hanging on a serin statement. 1. Is there a direct way to reset an 8M...

I've got a 08M hooked up to another uC...if I press a button, the 8M sends a short string with the serout command. When just the grounds are connected, a logic probe shows the signal on the pin, but when I connect the pin to the input on the other uC, the stream isn't there anymore. What gives...

Can I safely assume a "4k7", referred to often in the manual, is a 47k resistor?

How do I store word variables in DATA, and get them back again in the same condition? I keep having some kind of "transporter" problem, like in that Star Trek movie...

I have to move a servo with fluid motion, approximating a sine wave. I want it to move back & forth between its limits, with the fastest motion in the midpoint, and slowest near the ends. The limits will themselves change, but I can probably figure that out myself if someone can give me the...

I put a socket for a 24vdc wall adaptor on my prototype board, with a 7805 5vdc regulator and 47uF capacitor between ground and output (5v). The center pin is ground, both on the adaptor & the plug. 24v only goes to the Input leg of the 7805, and nothing else. This simply sends 5v to the...

I have an old 1-cylinder 2-cycle engine that has bad points. I can't get new ones, and I really don't want to pull the flywheel off of it. I was wondering about the possibility of making an ignition system, with either a Hall effect sensor, or perhaps an optical sensor. Would a Picaxe be fast...

Can someone shed some light on selecting pins as input & output, for bitbanging?

I need a few more pins, so it looks like I'll be upgrading to the Picaxe 14, or 14M. I can't seem to find it anywhere, including here, though I do see references to it in the forum. What happened to the 14?

I have to rig up some sort of logic gate, cheaply. I have 3 lights, only one of which will be turned on at any time. I only have 2 output pins free. I'd like to use a couple of transistors as a makeshift logic gate, as they're cheap, but I'm having a little trouble figuring the wiring out. Can...

I building an encoder using a photocell and illumination LED with a black/white disk on one of the gears. Has anyone here any similar experience? I'm concerned about data loss due to rctime lag. What is the maximum RPM I can expect to measure with an 8M?