Pic 16F913 Quick Reference Guide

I wrote a short Quick Reference guide for how I have been programming the Pic 16F913.

Check out the HOW TO here: Programming_The_Pic_16F913_QRG

Good luck and let me know how it goes.

Its should be pretty straight forward.

Emulator

Well I finally came up with a good project for my ECE 335 course,

I attempting to write an emulator for the Power PC 403 for the Microprocessors course ECE344, I was wishing the whole semester for the opportunity to have something to test on at home, so when I came into school to test on the actual boards I'd be able to know that my program would work as expected.

In keeping with ECE 335 I'm sure I'll write some "terrible" code without realizing it, at which point, I'll just go ahead and optimize it, this will have to be a really quick deal so initially I'm only going to support the addi command. Once that is up and working I'll reassess what is going to happen next.

The link to the project is here if you're interested in helping let me know.

https://code.google.com/p/powerpc403/

Counting

This is the VHDL for the counting algorithm from ECE 528 today.

Counting VHDL

System UCF

Finding Bugs

So I was working with a buddy on a program he wrote in Assembly, he had nearly the whole thing complete, and before he's able to actually test it, he did one of the smartest things I can recommend if you can't actually test the code until some future date.

HE ASKED SOMEONE ELSE TO TAKE A SECOND LOOK.

Better then just asking someone else, asking someone else who has a better, even if it's slightly, knowledge of the subject, can see things that you might not see.

Now sure sitting in front of the computer with the board next to you and assembling, loading, running, then going back to debug can gain you some invaluable troubleshooting experience. I won't lie to you, learning how to attack a problem can be invaluable, but one of the biggest key's to do that follows.....

The key for the second person here, is to guide the programmer to the problem spot without giving away the answer if they know it.

Why so? By forcing the person to look at the code EXPECTING a problem they're going to start analyzing each and every line, Is it the right command here, did I set that up right, did I move this pointer to the right spot. EVERY LITTLE DETAIL should get scrutinized by the programmer. And that is good, they'll learn TONS and begin to see the big picture here.

Once you code something up, re-read it, re-read it again, now compare it to your design.

Wait a second I snuck something in there didn't I?

It comes back to design huh. IF every piece of the code you wrote can be traced back to a design element you wrote, you can break the problem, if there is one into a tiny piece, and that's a huge factor when you're working with 1k+ lines of code in assembly.

It might not seem to make sense working with a 50 line piece of code, but if you can force the habit it will make you a better programmer. I promise!

The PIC 16F913

So I bought some PIC 16F913's I was hoping I could just literally plug in the PIC to the PicKit 1 and just program, turns out it's not that simple, but aside from hooking a couple wires up, well frankly it's not that hard. I just wired up the appropriate VSS, VPP, VDD, and ICSP Clock and Data lines.

One thing that threw me off, is that the microchip site said that the PicKit 1 programs the P16F913, this isn't "entirely true" I was able to use ICSP. Since I can't get MPLAB to program via ICSP, I was able to using the PicKit 1 Classic program, found on microchips website.

Here were my steps:

1. Hooking up the ICSP. I actually tried to do a "read" with the PicKit 1 Classic S/W, it recognized that it was a 913 AWESOME, this is really good news.
2. Load up a program into MPLAB and compile, turns out I was able to use the exact same "hello world" code from my 16F684, so I just compiled and was ready for the next step.
3. I then pointed to the hex file compiled by MPLAB, from within the PicKit 1 Classic program.
4. I just hooked up the appropriate pins to the LEDs on the board to make sure i was able to turn the LED on and off, if the S/W was working as I expected.

There you have it, it wasn't nearly as hard as I expected it to be, now that I can use the PIC16F913, well frankly I am pumped, the only thing I would really like to do is have a socket plug that I can use to directly wire up a ICSP port, then I can really just use a ICSP plug on any device/board and I "think" I can actually use it.

Next up is maybe serial communications? We'll see the sky's the limit now.

Networked memory

I just read an interesting article about how slime mold generates networks as efficient as the Tokyo Subway system, the only downfall looks to be related to redundancy.
Slime Mold Subways

Which get's me thinking, now that memory is a dime a dozen, can we have networks of the same data, and depending on where you are in the platter for example rather then having to travel say all the way across the platter to get the information, you can just stay in the local vicinity?

So Suppose you have the same data being transferred back and forth in different memory regions so they are all matching. Your head is already in a particular location of the platter, now rather then having to say move the head all the way from where it is to a location nearly opposite the location you currently are, there is a networked memory piece just a few micrometer's next to, or after what you're looking at. Now the disk doesn't need to seek as long, which tends to be the more time consuming part of data access.

Let me know what you think or do you think I'm off my rocker?

Deleting Files

I was having problems with a particular file, one of my scripts accidentally produced a file named such that I couldn't delete it.
I found a great tip here: Forum Post

All I had to do was find the filename using dir /x /a

Once i found that a simple del filename got rid of it.

Analog Inputs

I've been fighting since late last night trying to get analog inputs working on my PIC16F684.

I finally got somewhere this evening, oddly enough for some reason, in some regions of the pot it goes really quick then just a small bit over will slow it down drastically.

All my code does is initialize everything to setup RA0 as an analog input, then it turns on the ADC waits until it's done then toggles the LED and waits the amount of time in the combination of ADRESH and ADRESL, all I had to do was put ADRESH into the integer value I had, shift it 8 positions left, then or the ADRESL in, then pass it to my wait routine.

Outside of that it's finally working, the last hiccup I had was well frankly I forgot to turn it back on after trying turning it off as a troubleshooting measure. Of Course I'll continue to plug VERSION CONTROL, had I gotten this working and decided to play a little here and there to make it say be more sensitive, I may have done myself in by messing something up, now I have no fear of that.

I am posting the code on my SVN server, and one day would like to be able to make that public so everyone can get to it, but I suspect my ISP won't like me using a web server out of my house, so I'll for now plan to upload it to Google Docs.

Below you'll find the vid of the PIC Kit 1 in action with the LED's toggling quickly then as I rotate the pot it slows down.

Here's the code to do it, there may be some unneeded stuff, let me know if you see anything off!

Analog Inputs

For the sake of testing I uploaded this file to YouTube and am going to see what the difference in appearance is here!

Opening Mailto in Gmail in XP

One of the first things I did when I bought my netbook was to download chrome. Now I haven't actually clicked a mailto link until today, and guess what happened? Internet explorer in all it's glory opened up. I didn't like that. One of the solutions I found was to look for URI.mailto or something to that effect in the file types menu of an explorer window and make some changes there, but well I didn't like that method much and I couldn't find what they were talking about in the first place.

I started searching for the term mailto in the registry, and I came upon this line right below.

HKEY_CLASSES_ROOT\mailto\shell\open\command

Unfortunately I deleted the original line so if anyone has it I would really like to know what it originally said, but none the less I have the line to insert if you want Chrome to open up gmail and insert the mail address!

This brings me to my next point ALWAYS BACKUP YOUR REGISTRY in case you muck something up.

I changed the key

to the below (change out onaclov for your username) and you should be set to go! Of course if you want to use another type of email client and/or browser you're going to have to change a few things. Basically all I'm doing is calling the chrome application, and passing the gmail address with mailto and URL %1 passed to it. The ideal way would be to call the default browser

"C:\Documents and Settings\onaclov\Local Settings\Application Data\Google\Chrome\Application\chrome.exe" --app=https://mail.google.com/mail?extsrc=mailto&url=%1

Additional Notes:

Oddly enough I found that if I go to IE and click options and then programs it only shows Outlook Express and Windows Live Mail which I initially thought was the culprit and in some ways it might have been, so I did a search for Windows Live Mail.

I found this:

As you can see it looks like mine has an entry for GMAIL, which of course is completely incorrect

as I was testing some things out trying to get it to work, if you add a Key there and name it whatever you name it, when you go to IE and Tool Options and Programs and Email you'll see those entries the problem is I have/had no idea what to put in there which lead me to the initial piece of the post finding mailto.

If I had the original mailto contents I "might" be able to remember what that was doing and possibly setup the entry on the left (HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Gmail) to actually open whatever browser you want as well as whatever email client you want based on that location (rather then having to keep entering in the registry if you decide to change).

Well if you have any other items of note please let me know.

Good luck

Interrupts

In ECE 344 we learned about interrupts and how to use them, of course we were programming in assembly, so we had to setup our interrupt vector, then write some code at the appropriate offset.

That turned out to be pretty easy, but the problem is let's say we want to write some code in C and try to handle interrupts. This is a little tricky if you don't have all the information you need.

Well of course since I can't seem to think logically sometimes, I didn't look at any manuals and just headed over to stackoverflow.com, where I got some great answer's here: Interrupts

The simple answer was this:

void interrupt my_interrupt_handler (void) {

handle_interrupts_here();

}

I did some testing and once I had the right bit's turned on I just ended up in my interrupt routine with this (about 90% borrowed from here:Microchipc):

void interrupt isr(void)

{

if (T0IF)

{

TMR0=TMR0_SETTING;

T0IF=0;

RA5=1;

//code right here is executed every 800us

}

My newest project I'll be working on with this microcontroller is to find some way to create a simple serial interface which I can transmit and receive a piece of data. Since I can interrupt on a timed interval. I should be able to read data passed at an expected rate.

I'll keep you updated when I get more work done.

SVN

So today I would like to go over the importance of version control.

Take for example I was working on a program, I made some changes and it was working. Now rather then checking in my file and version controlling it, I just started modifying it. About half ways through I realized I meant to re-save the file somewhere but instead overwrote the changes that I had originally working.

When you've gotten a particular program working at some point, if you're dedicated enough to stick to version control, you check it in, then keep working, now if you have made changes and wish to revert to a previous working state it's REALLY EASY. Now of course simple enough you can just save multiple copies of a file, and keep renaming it and everything else. If you use version control you really only "see" one file and you just keep checking it in.

I have SVN setup on my server, and am using Tortoise SVN for my window's machine, and am enthralled with it. When you do a checkout in SVN it ends up copying the checked out folder into your current directory. Now when you make changes it shows a different icon on the folders so you can visually see that it's needing to be committed. Now if you're working with multiple machines/people you will want to make sure you update before commiting.

Once you've committed changes you're set.

Good luck and let me know if you need any help setting up your very own SVN server.

Max RPM II

Well I finally got a few minutes to mess with my arcade after cleaning the garage a bit.

So far I have the lights on the coin op working, the flourescent light doesn't fully light, so I need to find out if it's the wattage or what. The monitor doesn't turn on at all, and the speakers just give a hum. I have to assume that the system isn't "booting". I found a site I can use to help me with questions here: Arcade Museum

I have 120V going to my monitor and have checked a few IC's on the Turbo Cheap Squeak.

In the hopes of using another computer monitor I tried hooking up the Horizontal sync to a regular CRT, and the monitor said the frequency wasn't correct. So at this point I'm assuming that it's a no go on that CRT.

I'll post updates as they come along. Have fun!

Timed Shot Photos

So my original goal for this project was to take some pictures of the mountains at pre-determined times. I found that this might be useful in other cases as well, so I'm going to be building an enclosure next and allowing maybe a tripod screw mount.

S/W Requirements:

1. Set a period (eventually elsewhere, but for now in code)

2. Turn Camera on

3. Once camera's stabilized take a picture

4. Turn camera off.

5. Lather, Rinse, Repeat.

Here's some footage.

What is a web browser?

In commemoration of my 100th post, I decided to do a video post. Here I give a rough overview of what a web browser is. I'm sure it'll need more work, but hey it's a first and I just put it together with movie maker through windows.

The inspiration for this post was my mom, I was attempting to set her up with Google Voice, and when I was needing to get her to get on the internet she asked me "You mean click aol?". Unfortunately I suspect very strongly that my mom thinks that aol is the internet, and there are alot of people out there that think the same thing. Sit back relax, and hopefully I'm at least somewhat entertaining.

Once you've finished watching let's re-iterate what I'm trying to get across.

1. Web browser's are not the internet.

2. Web browser's are the vehicle that get's you to web pages.

3. You aren't stuck with only one web browser, you can try other ones.

4. Things you want to keep in mind are speed, real estate, following standards, usability, popups, and addon's.

Help Joe get an iPod touch

I posted a site joe.onaclovtech.com, hopefully I can get alot of people to donate a little, and we'll all get Joe an iPod touch.

Thanks anyone that helps out.

#joesipod

Clonezilla

Well I finally went about the task of imaging my hard drives.

I decided to use CloneZilla, as I read from lifehacker this would be best as well as a few light searches on the net seemed to refer alot to CloneZilla.

I ran into some problems, there is a USB helper that they recommend, that wouldn't boot my SD and/or my USB thumb drive.

I basically had to use Unetbootin, the nice thing is you can point to the .zip file you download from clonezilla's website and it treats it just like it's an image file and builds everything up for you on your drive.

Once I got that all working there were a couple more things I ran into. I'm assuming that my wifi wasn't going to work with this light "OS" so after a few tries I finally hooked into ethernet.

Once I got past that I found out that it was expecting a folder called partimag on the home directory, so I had to make that folder.

I also ran into problems when trying to specify my samba server, if I just pointed it to my ip address it seemed to have problems, so I actually pointed it to ip\folder, and that worked.

From there it was literally a cake walk.

Google Voice Ideas

I was logging into google voice again, and found myself in a familiar world. I send a text message, and when the person replies it's in my inbox AND my phone. The problem is, I have one of those crappy phones so I have to constantly be deleting messages because I run up to the limit.

Here's my thoughts, if you get a text message in Google Voice AND you're logged in, it gives the text message say 1 minute to sit in the inbox doing nothing, if you immediately respond INSIDE google voice, it doesn't bother sending it to your phone, additionally you could add a "send to phone" option for a text, then it will still send it to your phone in the event you're getting directions and you won't have internet access when you leave your computer.

Well there you are just one more idea.

Troubleshooting

One of the biggest challenges in ECE 344 is troubleshooting on the system.

I mean walking through typing stp, then rrd when you want to read the registers.

In comes typical troubleshooting without a debugger, normally you stick some print statements in there and wait for the print fest to begin.

This bothered me because we can't really do this in our architecture very easy. The nice thing is that we learned about sub routines, and you can treat sub routines as functions if you do it right, so what did I do?

I wrote a sub routine that will print the register values at the time you branch and link, the main limitation, is that interrupts can change your register values once you've entered into the subroutine. This is where the mailbox architecture comes in, if you design your system so that the interrupts do as little as possible and leave everything as untouched as possible, you can then go into your print subroutine and it will print the register's last value.

There are probably plenty of other uses you can find for this routine, and maybe even better ways to use it, for example when you enter this subroutine it waits for a key press before you can exit. Once that happens you can return from your branch and link, this is great because now you don't just blow through your whole program before even really seeing anything.

This is untested code as I am unable to make it to the school until Monday at the earliest, but if you want to give it a try I'll link to it at the bottom.

Changes you'll want to make to allow this to integrate with your program is finding your location in memory you can stick the long ascii string I've built.

Additionally you'll need a 32 bit to ascii converting branch and link, which i haven't written, but we have written for our latest program. This will convert the actual register values to a printable value, as well as you'll need a push and pop routine at the beginning and end, with the pointer jumping by 40 each time, if you don't have this you'll have to find a way to get the data from the register's instead of memory as I'm doing.

As I have time I'll upload more files and a more complete solution but this is very far along and should only require small amounts of modification.

NOTE: As with any file you download from google documents, unfortunately just directly downloading it will have format issues. Copy and paste the contents to a new file and save as a .s file, otherwise you'll be chasing your tail trying to find problems that really don't exist.

Check out the code here: Print Function

Thoughts on OS's

So here are my thoughts on os's these days.

I just recently got my new HP netbook. It's a great little device, but here's my worry, it's not very powerful and it's running windows, My old laptop is running windows as well and is slowing to a crawl.

What are some common causes of slowed down computers?
From Computer Hope:

Hard disk drive is short on available disk space.
Several software programs have been installed/uninstalled leaving behind bad files and/or confusing the software.
Data Corruption.
Outdated drivers
Computer is overheating.
Corrupt OS.
Bad Hardware.

It would appear there are two common causes here.
1. The hardware capability is declining.
2. Operating System related errors.

Hold up before you start getting all upset and claiming that if the people who wrote the programs cleaned them up right then you wouldn't have these problems.

What I want to know is why these programs are becoming so integrated with the OS that the OS can't simply clean itself up?

I was watching the Google OS talk as well as reading a little on it. One of the things I noticed and it's becoming a bit of a theme across OS developer's now a day's.

Let's build OS's that are designed for specific hardware and really only market for that.

What I'd really rather see is OS's that when you load them up will look at all hardware connected and self configures itself to be the most optimal OS for that hardware. What this means is now instead of having 300 print drivers loaded into your system and 45 wireless network card configurations, the OS looks at what you have and decides what's best and get's rid of the rest. Typically true hardware to the system should have only those drivers loaded, no more, no less.

I know this sounds crazy and in some ways it is, but what happens next is the OS is also linked up with the web, so let's say you plug in a new hardware item a new sound card, a new stick of ram or something. Things might be a little hokey but with a basic set of drivers that will control (in a limited way) most hardware, you now tell the computer to rescan for system updates, at which point you can optionally load the new driver's for this new device onto your system, and again it re-configures itself to run as optimally as it can with this system.

What can this mean for boot up times? Well if the OS doesn't have to constantly be verifying what equipment you have and assume you just plain have it and go forward from there. If/When it runs into a hiccup such as it expected a stick of ram somewhere and didn't see it, it jumps to the degraded mode until you either update and "auto" re-configure the system or repair the problem.

I think if you can resolve hardware checks as well as re-design the bootup to start simultaneously kick off processes that will help considerably.

Once more, you won't have to constantly be pinging the devices (wasting power) just verifying that the components are there.

Syntax

Syntax doesn't require a whole lot of explaining. Mainly get a good source of information that you can understand, in this case we really only get a .pdf file with the reference manual so you really need to make the best of it.

In our "compiler" the system converts the assembly code that you wrote to a 32bit instruction.
This instruction can be analyzed by the student by breaking it down into opcode, from there that will tell you what kind of data can reside in the rest of the instruction.

One thing I'd like to do is write a syntax checker for the PPC 403 that we're using. This would be particularly helpful in writing code off site, and then making sure the syntax is right.

Once you can sucessfully "compile" then you're on to the testing, and possibly will return to this section.

Let me know what you think!!