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I have an interesting problem that I will put out to the community for suggestions. I would like to place a sensor over a black or white square (created using toner on a laser printer), and get out a ~5V or ~0V signal. I would like to use the QRD1114 IR LED/phototransistor combo if possible...

http://chrisfenton.com/diy-laptop-v2/

So I'm attempting to use a ps/2 keyboard wired directly into a 28X1 chip for a project I'm working on. There are 10k-ohm pull-up resistors on the data and clock lines, and all of the connections appear solid (I measured them with an ohm-meter). It is powered either off of a 5V bench supply or...

So I am attempting to build a keyboard FIFO buffer using a 28X1 as an i2c slave to another 28X1. I developed a sort of handshaking protocol to let them exchange data: In the scratchpad ram, 0x00 = keyboard status byte (Empty=0, ready=1), and 0x01 = current character. Here is the code: '0x0 =...

Has anyone else had really bad luck with 28x1's? After using tons of 08M's and 18X's for years, and never losing a single one, I've somehow managed to brick 2 28X1's while working on the same project! I don't appear to be doing anything unusual, but this is starting to drive me crazy! (those...

Okay, this is one of the weirdest electrical problems i've ever experienced. When writing to an i2c FRAM chip (FM32256 from Ramtron), on a number of random locations (4,20,68,84,100,116,132,148,164,196,212,228,244 - in the first 255 locations), the 5th bit (2^5=32) is stuck at 0. I noticed it...

I was fiddling around with a large LCD (24x8 character serial) I had lying around, and I was actually able to get a simple "PONG" animation displaying on it at ~10+ FPS (guessing . . . it was extremely fluid with no noticeable "flickering" or "jumping") with a 28x1 @ 16mhz. I know other people...

Hello all, I just built a new 28X-1 board, soldered everything up, and tried to do a firmware check with the editor. All of the connections look fine on my multimeter, but no luck. The chip was initially connected to a 20 mhz resonator, so i thought that might be the problem, and unsoldered it...

Here is a DIY Picaxe-based "Laptop," built using an 18X chip and a 24LC512 i2c memory chip. It runs a simple assembly-like language, and includes the following software: * Text editor that can edit up to 4 different programs at a time * File manager with space for 10 ~1000 line programs *...

After entirely too many hours of work . . . behold! The first ever picture taken from a picaxe:

Hi, I'm trying to figure out a way, using 2 9V batteries, to generate a voltage sweep from -9V to +9V on an output. I would like a picaxe to sweep the voltage over about ~.5 seconds or so. Any thoughts?

I'm using a 28X-1 with the A.0 firmware, and version 5.1.1 of the programming editor. Reading from the chip works fine. Whenever I attempt to write to my 28X-1 chip, though, the data never seems to get written to the chip. I'm using the following code for the i2c slave chip: hi2csetup...

I'm wondering if it's possible to build a picaxe-based FIFO for a ps/2 keyboard? Possibly using a dedicated 18X chip (does the Keyin command allow PWM to continue in the background? Also, can Keyin be halted by an interrupt?). I'm trying to come up with a way of making keyboard input more...

Given 2 commands like: For(variable,start_val,end_val,step_val) Next(variable) How would one implement this, while maintaining the ability to nest them? my first thought was to store the following: -step size -variable -address of "For" command -address of command following the...

Anyone think it's possible to write a sort of "meta-BASIC" interpreter using the picaxe "native" basic? I know I and hippy have both made assembly-like "meta-languages", but the 28X-1, with its 4k of program memory, makes me think this would be really possible (and...

I was wondering, how does the picaxe store numbers internally? For the "pause" command, for instance: Pause 5 = adds 1 byte to code Pause 16 = adds 2 bytes to code pause 255 = adds 2 bytes of code pause 256 = adds 3 bytes of code pause 65000 = adds 3 bytes to code I was thinking it...

Okay, so now that I have my 24x8 character LCD working, I have a challenge for the crowd here: Is there any way to semi-reasonably display a 128x128 pixel image on a 24x8 character display? The "character" cells are 5x8 pixel groups, and they're unfortunately slightly separated. I can...

Hmm, so I purchased one of these 24x8 character LCD's off of ebay (http://cgi.ebay.com/NEW-SERIAL-24-x-8-LCD-WITH-CONTROLLER_W0QQitemZ120093993964QQihZ002QQcategoryZ50915QQrdZ1QQssPageNameZWD1VQQcmdZViewItem) Whenever I power it on, though, all of the blocks turn on and come up solid, and I...

So here is the setup: I have an array of 12 tiny solenoid valves mounted over a 36" conveyor belt that is being driven by a 1/30 HP, 90V motor (and is located about 8 inches from the valves). I have a chip (actually an FPGA) that outputs 2.5V for hi and 0V for lo, and is driving 12 NPN...

So I have an 18X that will identify its firmware (8.6, btw), but then it gives me a "Error -memory verification failed (Byte 511)" message when I try to download. Any thoughts? I'm working on a kind of last minute project, so help is appreciated =)