All Blog Posts (123)

There seems to be a mistake, because the code did not work, and after my change, it did work.

MainLoop

    bsf        ADCON0,2        ;start conversion and wait for it to complete

    btfsc    ADCON0,2

    goto    $-2

goto $-2 is wrong, because it goes back 2 lines and starts the conversion all over again. You'll want to goto $-1 instead, to just test until the conversion is done.

However, I would reccommend this…

The information regarding the EEPROM is minimal in the manual and you will need to go into the datasheets to get a bigger picture (as is the case for pretty much everything). This post is just to add to the stuff the manual is missing, so that you do not have to go searching through the datasheet.

First off, the datasheet itself uses VALUE and ADDR as registers to contain the data it would like to store. If you implement the code as is, it will not work. You will need to…

http://dozydagger.com/misc/mpasm-lcd-writer.html

You know what I say to tables? Well, I don't say it, because I am not the type to publicly use such language, but once you get past the character limit it causes problems that can be tricky even if the solution is known.

Here's a work around that I'm using. "can" wasn't worth making a table for. A table would take 4 lines. If you include the code to…

• Get the address of index zero of the table
• Add the table index to the address
• Jump to that address

The table itself is a sequence of retlw instructions, which put a value into W and return. (dt and related directives are just assembler shorthand for inserting many retlws.)



A first try at implementing a table lookup thus looks like this:…

I found a plastic vendor that sells acrylic tubes that are the perfect size to stack the tires (5" inner diameter and 5 1/4" outer diameter).

The only problem is that they only come in 6' long tubes. The 6' tube is ~$50 so I'm looking for 2 other groups who want to split up the 6' it'll be $15-20 for your 2' section of tube.

Heres the webpage for the plastic vendor…

If there is a certain length of code coming before the DT (define table) directive, then characters/entries in the DT past a certain point will fail to return a value. Instead, upon reaching that character, the program will restart from the beginning.

Remember, or realize, that DT is actually a short form for a long list of retlw instructions. That means that having a DT holding a long string counts as many instructions.

This does NOT appear to be an issue of…

In one of my define tables, if the table gets to a certain length I get a bug in my code. Just take one character away from that and everything is fine. I have found no significance in regard to... actually, I never counted it until now.

If there are 33 characters, my code bugs out. 32 is okay. Well, 32 is a very important number, but I have longer tables elsewhere. There is also no reason for this to bug out. It's simply absurd!

Each dt (define table) directive uses up a line for each character in your table/string. If you're not careful, your code could get long despite being short.

Here's how the define table directive works. Each character in your string is actually translated into a single retlw (return literal in W).

For example:

dt "Hello!"

is translated into:

retlw 'l'
retlw 'l'
retlw 'o'
retlw '!'

If the path size of your MPLAB project's directory is too long, for example:

C:\Users\Main\Desktop\ritchie-thai\current-projects\aer201

then a .hex file will not be created.

I am now using a workspace with the much shorter path:

C:\mplab-test\KeyPad_LCD

Don't computers suck?

Tennis%20Ball%20Rolling%20Experiments.xlsx

tl;dr

I rolled about 1000 tennis balls down an incline. It turns out that you need an angle greater than 7.7* to ensure a column of tennis balls will roll without error.

list p=16f877                 ; list directive to define processor      

#include <p16f877.inc>        ; processor specific variable definitions    

 __CONFIG _CP_OFF & _WDT_OFF & _BODEN_ON & _PWRTE_ON & _HS_OSC & _WRT_ENABLE_ON & _CPD_OFF & _LVP_ON

cblock 0x20

 COUNTH

  COUNTM

  COUNTL

endc



         ORG       0x0000     ;RESET vector must…

Altium and Eagle are great softwares for PCB design. The softwares can be used to generate schematics and this information (all the parts and connections) can be automatically transferred to a PCB design layout where the parts can be manually arranged and then automatically routed (for relatively simple layouts). Altium also has a simulator and a 3D design layout mode that is helpful for complicated design. Eagle does not have these functions. However it is much less expensive than Altium.…

Download Here

... and doc: retards.org/library/technology/electronics/pic/libraries/karl_lunt/picmacro.pdf

Transactions: A USB transaction has three parts: the token packet, the optional data packet, and the status packet, which represent the header, payload, and data

acknowledge, respectively. Since USB is host-driven, the host initiates

transactions by sending the token packet. It also sends packets to indicate the

start of each frame, every millisecond. Packets on this layer are taken care

of, so the…

Often times in project coding development, the programmer need to generate some sort of delay. It is hard and tedious to calculate by hand, an alternative way is to use the Pic Delay Code Generator for ASM Programmers made by N Golovchenko.…

It is quite clear that the I2C bus can be very confusing for the newcomer. This short article therefore tries to de-mystify the I2C bus, I hope it doesn't have the opposite effect!…