Welcome
Welcome to KD0YU.COM
This site is dedicated to the pursuit of EDA design, microcontroller development and programming... as it always has been. Throw in some linux tech, sendmail and mail filtering rules, sprinkle it with some random thoughts and you got yourself a website.
This site was reincarnated on 15SEPT11 and not entirely open to the public.. yet. Content will be VERY limited while I get the site configured and tested. Obviously security is a concern and I want to make sure it's safe before I put it online.
I will be hosting some projects I've been working on in hopes that they may be of use to the community at large. I've recently been working on a PIC18F4550 development board. Simple and straight forward with a SOIC 8 MCP7840N RTCC chip onboard. I've also put together a port expansion board that uses the MCP23017 I2C Port Expander chip... looks very useful.
The boards should be here on or about 17SEPT11. I'll try and get some pix during my first assembly posted as soon as I can ;)
As I said earlier, not entirely open to the public. Project files, when posted, can be downloaded by anyone. If you care to post replies/input/questions, you'll need to register here on the site with a real email address (I'm an EE, not a spammer!) and a reason you'd like to post (english and intent test, could be hard for some ;). Spam sites need not apply.
I also enjoy working on the spam filters on my mail server. Kicking ass and taking ip's is a very enjoyable pastime (if your into that sorta thing). Mailfromd and MailScanner are a formidable pair. I get NO spam and I'm not about to start.
Enjoy your stay.
--Dave
Access
If you are interested in collaborating on a few electronic designs, coding, or are interested in a few of mine; drop me an email to This e-mail address is being protected from spambots. You need JavaScript enabled to view it. and apply for a username here. Include a 'what and why'. After review I'll grant/deny access to various parts of the board.
For those that would just like a user/pass, again apply for a user on the board and drop me an email stating your intentions. No gmail or hotmail accounts will be accepted... period! For pete's sake, if your serious about what you do, get a serious email address.
For now I have enabled OpenID login. Should make it a bit easier to access content here. I'll disable it if I feel it's being abused.
While all of this may sound like I'm paranoid or something, I assure you I am not. I just don't need the idiots and spammers floating around causing trouble. Serious inquiries only!
--Dave
I2C for the 8051
I recently found a library (albeit small) that bit bangs the I2C protocol on port1 of a non-i2c 8051. This is GREAT!. I could now get my legacy development system to talk to some of the newer RTCC's, eeproms, and port expansion chips.
My first order of business was to get my dev board wired to a Microchip MCP7940N RTCC I've had laying around for a while. I was stunned when it worked the first time! Fascination ensued and I spent the rest of the day coding a menu system to read/write the clock chip with time and date, alarms, alarm trigger output, and the ability to turn the backup battery on and off. I'd like to share this code with anyone else struggling with I2C or the MCP7940N (or both). I'll have it bundled and posted shortly. (17SEPT11)
Rev 1.2
After working on version 1.0 for a while I realized there were a few shortcomings in the design. Not show stoppers by any means, but features that were handy to have on the board... not on a peripheral. Version 1.0 worked as intended and is running a temperature monitor and RTCC continuously as I write this. There was not a flaw on the board, I am really happy with it.
But, it needed some extras so I started work on version 1.1. I added a dedicated LCD port, a MAX232CSE, RS232 connector and glue, and a USB port/connector. The design software didn't have an up to date component for the USB connector so I needed to model a new one. If you've ever had to layout a complex footprint, you know what I'm talking about when I say it takes time.. cuz it better be right! This brought the board size to a whopping 3"x3.5". Wow. During the research on the chip for the USB support I learned about the SSP port and it's functions. STOP THE PRESSES!!!
PIC18F4550 Dev Boards Arrived
[Enlarge]
They just arrived, now if I could just get this grin off my face I could assemble one of them.
Smaller than a credit card. PCBCart in China did a fantastic job on the boards. I submitted the artwork on the 9th of this month using their standard 12 day service, and got the boards on the 17th via FedEx Standard! Now that's service! Much better than my experience with PCB-Pool.
A3799 Stpper Driver Board
This is an ongoing project I've started about 4 or 5 months ago. In an elusive search to find a decent stepper motor driver circuit without breaking the bank, I've narrowed it down to this, A3799_Stepper_Driver [schematic, PDF]. Board diagrams and artwork to follow shortly.
Update 23SEPT11: While the circuit is still viable, I am abandoning this project. I ordered a couple of the A3799's from Digikey earlier in the month and they have arrived. TSSOP chips... too damn small to work with, and too fragile to do anything with a CNC machine. I'll finish off what I have, bundle it up and post it shortly. (I have a lot on my plate at the moment).