Physical Computing 053

2006-05-26T18:49:00.000-07:00

Final Project Final Post
Whoops, forgot to get this up by 10am today.

Annnnnnywho, last project, nicknamed Death Buttons by Prof. Jacobs, is an 8 button control pad which uses serial byte transmission to differentiate between the 8 different buttons. I had a few ideas for games to integrate the 8 buttons and their orientation on the game pad. The buttons are arranged in two columns to allow for two-player use without being cramped, as I was initially hoping to create a head to head game. One game idea was a sort of soccer-pong with 4 goals on each player's side, and the buttons would be used to move the goalies to a corresponding goal to defend/shoot a new ball. However, time constraints along with being way out of practice with Director eliminated the game from the equation.

The controller sends ASCII symbols as bytes for each button. Player 1 has buttons which send A through D, and player 2 gets lower case a-d. In this respect, the controller works properly, and gives discrete and distinguishable input to the CPU. Here's my code.

Public Const LeftA as Byte = 15
Public Const LeftB as Byte = 16
Public Const LeftC as Byte = 17
Public Const LeftD as Byte = 18
Public Const RightA as Byte = 10
Public Const RightB as Byte = 9
Public Const RightC as Byte = 8
Public Const RightD as Byte = 7

Option Explicit

Public Sub Main()

Dim button as byte
Dim outQ(1 to 40) as byte
Dim inQ(1 to 10) as byte
Dim outString as string
Dim state as boolean
Dim bNum as byte

call openqueue(inQ, 10)
call openqueue(outQ, 40)
call definecom3(11, 12, bx1000_1000)
call opencom(3, 9600, inQ, outQ)
do
for button =7 to 10
state = getpinvalue(button)
if state = true then
if(button = 7) then
'outstring = "Right D"
bNum = 100
call putqueue(outQ, bNum, 1)
end if
if(button = 8) then
'outstring = "Right C"
bNum = 99
call putqueue(outQ, bNum, 1)
end if
if(button = 9) then
'outstring = "Right B"
bNum = 98
call putqueue(outQ, bNum, 1)
end if
if(button = 10) then
'outstring = "Right A"
bNum = 97
call putqueue(outQ, bNum, 1)
end if
end if
next
for button =15 to 18
state = getpininvvalue(button)
if state = true then

if(button = 15) then
'outstring = "Left A"
bNum = 65
call putqueue(outQ, bNum, 1)
end if
if(button = 16) then
'outstring = "Left B"
bNum = 66
call putqueue(outQ, bNum, 1)
end if
if(button = 17) then
'outstring = "Left C"
bNum = 67
call putqueue(outQ, bNum, 1)
end if
if(button = 18) then
'outstring = "Left D"
bNum = 68
call putqueue(outQ, bNum, 1)
end if
end if
next
' delay 0.1
loop

End Sub

Public Function GetPinValue(ByVal button as Byte) as Boolean

if(GetPin(button)=0) Then
getpinvalue = false
else
getpinvalue = true
end if
end function

Public Function GetPinInvValue(ByVal button as Byte) as Boolean

if(GetPin(button)=1) Then
getpininvvalue = false
else
getpininvvalue = true
end if

At first I attempted to send the data as strings, but quickly switched back to bytes for the sake of simplicity and achieving function. The two functions define the 'pressed' state for each player. I did not realize until I got home that I had purchased a 4 pack of naturally-open buttons and one pack of naturally-closed. Breaking my code into two parts with inverted check functions quickly solved this and stopped player 2 from sending all 4 buttons all the time.

The device is housed in a project box from radio shack and has an integrated serial cable design. Power is supplied from the wall adapter and a mounted power jack on the box itself. Pictures will be up once they are uploaded to mycourses.

2006-05-25T02:05:00.000-07:00

reboot and i can talk to the chip again. woot.

2006-05-25T01:30:00.000-07:00

I have lost complete control over the Com ports, and I am unable to halt the processor, although i was halting it not even half an hour ago with the only changes in code being the addition of these lines:

l1 = cInt(getPin(left1))
l2 = cInt(getPin(left2))
l3 = cInt(getPin(left3))

debug.print "l1 = "; cstr(l1)
call delay(1.0)

This is literally all which has changed in my code and now I can not reset, halt, or download new code AT ALL. This is exactly what happens when I try to download new code.

turn power on
click halt processor
error: unable to halt processor
error: closing download port

i go to close the DL port manually
re-open DL port: com1
error: unable to open Com1

when i open and close it a few times, it works, but every second attempt it repeats that it is unable to open Com1. when it does not throw the error, i get crazy output which changes every time I attempt to stop the processor.

µµµµü««««mmmmmmm

are the three symbols i get before BasicX throws a runtime error and shuts itself down.

grr

2006-05-25T01:05:00.000-07:00

4am

when attempting to compile my latest iteration of code, i have been receiving all kinds of weird errors. the BasicX editor and downloader are suddenly having trouble opening the Com1 port, which is leading the problems stopping the processor to download new code. Also, after the Com1 fails to open (even though it is open in the options, and I close and re-open it just to be sure), I get a runtime error which crashes BasicX so hard that it closes the program windows.

just another update to how much this isn't cooperating for me :-(

i'm getting more and more irritable and less patient as time goes by here. it feels like my mind is running at half power and i'm fighting off keyboard-napping.

2006-05-24T11:53:00.000-07:00

It is now Wednesday afternoon. 2 of the past 3 days have been all-nighters to complete final work for other classes, and today when I went to the open lab session around 11:45 and found a note saying to go to Crossroads to find everyone. Did that and wasn't able to find anyone, so I went back home to BEGIN this project. Looks like a third all-nighter in 4 days. Can't wait to clear out my entire apartment and drive 5 hours home in my already sleep-deprived state tomorrow.

Updates as I progress, I shall probably be working right up til 8am tomorrow.

2006-05-15T10:06:00.000-07:00

The car is now working to some degree. I programmed as much functionality as I could without constructing an H gate or some other kind of polarity-switching device, so it runs forwards but not reverse, and can turn left only. However, I have the car responding to all 4 types of radio input without errors when commands overlap. When the controller sends the signal to drive forward, the car drives forward until the stick is returned to the neutral position. The same goes for left hand turns. However, when you press down on the throttle stick, the brake lights illuminate, and a right turn actually switches on the headlights. All in all, I have managed to use the BX to cut the functions of a toy car in half, with the exception that I added some lights to the mix.

The most difficult aspect of this was interpreting the radio receiver's signals. I used LEDs connected to each of the 4 outputs to check where voltage was present. For the forward/reverse functions, up sends power to one pin, and down sends it to the other. For steering functions, the neutral position sends equal voltage to both pins, and when a direction is chosen, that side receives a higher voltage. Here is the code I used to make these unusual inputs usable. The Forwd and Leff functions control the longitudinal and lateral motor controls.

Option Explicit

Public Const radiorvs as Byte = 10
Public Const radiofwd as Byte = 11
Public Const fwd as Byte = 12
Public Const left as Byte = 13
Public Const radioright as Byte = 14
Public Const radioleft as Byte = 15
Public Const tails as Byte = 16
Public Const heads as Byte = 17

Dim reverse as integer
Dim forward as integer
Dim lft as integer
Dim rgt as integer

Sub Main()
do
call Forwd()
call Leff()
loop
end sub

Sub Forwd()
forward = cInt(getpin(radiofwd))
reverse = cInt(getpin(radiorvs))

if forward > reverse then
call putpin(fwd, 1)
call putpin(tails, 0)
debug.print "forward"
elseif forward < reverse then
call putpin(fwd, 0)
call putpin(tails, 1)
debug.print "not forward"
else
call putpin(fwd, 0)
end if
end sub

Sub Leff()
lft = cInt(getpin(radioleft))
rgt = cInt(getpin(radioright))

if lft > rgt then
call putpin(left, 1)
call putpin(heads, 0)
debug.print "left"
elseif lft < rgt then
call putpin(left, 0)
call putpin(heads, 1)
debug.print "right"
else
call putpin(left, 0)
end if
end sub

Interestingly, I am able to decipher the bizarre ADC values from these 4 inputs by casting them to integers and instead reading the getpin value. Because of the unusual method the radio uses to send voltages (both positive and negative switching) the ADC values were hard to read and all 4 fluctuated when any control command was sent by the transmitter. The if elseif else statements were more or less a short in the dark, but they work spectacularly well.

2006-05-10T10:39:00.000-07:00

Today in class I was able to isolate the voltage bounce I was seeing last night. 8 drop-down resistors later, I wish I hadn't forgotten the radio controller at home, since I believe I'm now able to see usable input from the radio receiver. I added some code to show the ADC voltages of all 4 radio lines. With the transmitter nowhere in sight, these are the baseline voltages.

*** Downloading File

Writing internal EEPROM
Verifying internal EEPROM
Verify OK
Writing external EEPROM
Verifying external EEPROM
Verify OK

*** Finished Downloading
rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

rear1 ADC =0
rear2 ADC =0
front1 ADC =364
front2 ADC =1020

Gotta see how those are affected when I manipulate the controls...

2006-05-09T21:52:00.000-07:00

My project has taken a totally new direction in the past 2 days. I have decided to use the BX chip as a replacement for the onboard logic in a small r/c car . After some creative destruction, the breadboard rides on top of the Lancer as gracefully as a mattress on a pickup truck. When hacking the car, I spliced the BX inline between each of the 4 main radio commands; forward, reverse, left, and right.

Here is some of the first output I saw when I plugged everything in. I have to determine what needs to be done to eliminate the voltage bounce so I can see what kind of input I need to interpret in my code. Here's what I'm lookin at...

*** Opening file: K:\bx\RCcar.bxb

*** Downloading File

Writing internal EEPROM
Verifying internal EEPROM
Verify OK
Writing external EEPROM
Verifying external EEPROM
Verify OK

*** Finished Downloading
rear1 ADC =438
rear1 ADC =129
rear1 ADC =0
rear1 ADC =10
rear1 ADC =124
rear1 ADC =251
rear1 ADC =82
rear1 ADC =0
rear1 ADC =0
rear1 ADC =0
rear1 ADC =10
rear1 ADC =128
rear1 ADC =263
rear1 ADC =65
rear1 ADC =0
rear1 ADC =0
rear1 ADC =11
rear1 ADC =135
rear1 ADC =253
rear1 ADC =64
rear1 ADC =0
rear1 ADC =0
rear1 ADC =10
rear1 ADC =152
rear1 ADC =290
rear1 ADC =67
rear1 ADC =0
rear1 ADC =0
rear1 ADC =15
rear1 ADC =155
rear1 ADC =291
rear1 ADC =64
rear1 ADC =0
rear1 ADC =0
rear1 ADC =11
rear1 ADC =151
rear1 ADC =292
rear1 ADC =69
rear1 ADC =0
rear1 ADC =0
rear1 ADC =4
rear1 ADC =37
rear1 ADC =185
rear1 ADC =277
rear1 ADC =40
rear1 ADC =0
rear1 ADC =2
rear1 ADC =37
rear1 ADC =184
rear1 ADC =276
rear1 ADC =35
rear1 ADC =0
rear1 ADC =1

I hope this will work the way I'm trying to do it. I'm attempting to use 2 separate pins sending alternating positive voltages to control a single motor in two directions (without PWM, this is my own 4 pin method) Going to see what I can do about that oscillation now...

2006-04-24T10:31:00.000-07:00

Amazingly, today was a day where nothing went wrong. I hacked my null modem cable and made a sturdy, 5 foot long direct plug-into-the-breadboard module. Also fiddled with my wiring and got my motor to work from chip input. I am still working on the user experience chart for the motor assignment, that is being updated and stored as a draft on here, so once it is complete, it will appear with the time and date I first started it. Not too much else is new, feeling pretty good about a day without hangups :)

2006-04-12T09:24:00.000-07:00

Okay, last night was I was too tired to put up everything that's happened since my last posting, but today's the project deadline, so I may as well catch everyone up.

So I pulled out my multiple LED bars in favor of creating more useful user output. Since I am still somewhat pressed for a good concept, I have created a device which performs multiple functions, responds to digital and analog inputs, and has a fun little easter egg which you'll see soon enough.

Back to the bars. I wanted to use the single digit display I picked up Glenwood at create some kind of readable feedback. I searched for the pinout for this specific model, and found this easy-2-read document.

http://www.intertie.org/HP5082-7740.pdf

After a little sketching out I had a list of pin combinations I needed to activate to produce the numbers 0-9. I decided to use nearly the entire left hand side of the BX (digital only side) for the 7 inputs the display utilized. After hacking a cat5 cable, I was able to construct a color-coded wire harness for easy of use. Stuck the display at the bottom of the breadboard, plugged in the headers on both ends of my 'cable,' and it was ready to roll.

Next I wrote some simple code to illuminate each number. Here's '5'.

Private Sub NumFive()
call putpin(d1, 1)
call putpin(d2, 1)
call putpin(d4, 1)
call putpin(d5, 1)
call putpin(d7, 1)
end sub

This is the point where I pretty much learned my way around BasicX. As I added lines early on, I quickly learned that I was overusing delay and creating an impractically long loop time.
I moved each individual function of the project into private subs. Shortening the main sub showed improved performance and made the debugging process easier. Here is the final version of main.

Public Sub Main()
do
slide = getADC(slider)
solar = getADC(photo)
dip3State = cInt(getpin(dip3))
dip5State = cInt(getpin(dip5))

if (dip3State = 0) then
call putpin(grnLED, 1)
call putpin(redLED, 1)
call OboeShoes()
call Delay(1.0)
call putpin(grnLED, 0)
call putpin(grnLED, 0)

elseif ((dip3State = 1) and (dip5State = 1)) then
call putpin(grnLED, 1)
call AnalogInput()
call Delay(0.5)
call putpin(grnLED, 0)
elseif ((dip3State = 1) and (dip5State = 0)) then
call putpin(redLED, 1)
call SolarInput()
call Delay(0.5)
call putpin(redLED, 0)
end if
loop

End Sub

'slide' and 'solar' are my two analog inputs, a photocell and a 100-10kohm slide pot. dip3 is a physical switche which toggles between displaying the slide or the photo input using the number subs. While this is a fully functional device, I still felt it lacked a tangible purpose. Now, at some point my housemate walks in and asks why I only have numbers, and no letters. I think hard to all the fun things you can write on an upside down calculator, and it hits me....

2006-04-09T13:09:00.000-07:00

As the clock ticks and I am trying everything I can possibly think of to get voltage from the pins, I ran the a rescue on my BX from the BasicX downloader. Reloaded some test code I wrote which I am sure will work. FINALLY! I am getting a reading on my pins. I have also discovered that most of my LEDs do not work, but after going through over a dozen, one finally lit up. Eureka! Let there be light! And all that jazz.... So I have decided on a concept for my blinky thing. I'm going to build a time machine based on the BX-24 to take me back to a week ago. For right now, I'm going to test all my lights and find enough to build with and crack a Red Bull for the evening. Still unsure as to the cause of the strange behavior. At least if it happens again (has twice already) I know how to get it going again.

2006-04-09T07:45:00.000-07:00

It's been some week up to this point. I have experienced nothing but repeated technical difficulties since the gitgo with this project. I determined the cause of my issues earlier to be the cable I purchased. Any naturally female to female DB9 cable is a null modem cable, with a crossed over layout. Additionally, the pin numbers in the lecture slides which correlate to the pins on the BX24 are numbered in reverse, as they would appear at the back of the computer or the male end of a female-male standard cable. Needless to say, I wasted a fair amount of time trying to make my cable work, with no real success at the end. The crossover adapter I soldered works about 80%... it can do everything except halt the processor to download new code.

The past 3 days or so I have been continuing to try and make the in class exercises work. I have had some degree of success manipulating code examples and putting them onto the BX, however I cannot seem to create any off-board output. I took a pre-existing LED blinker code which created output on the green and red LEDs on the board (pins 26 and 25 respectively) and added a third output, pin 13 exactly as demonstrated in the slides. No output. Nothing. I have no idea why declaring a pin such as 12, 13, 15, any of the acceptable output pins, does not work. I am wondering if something is damaged. Here is the exact code I am running.

'-------------------------------------------------------------------------------
Option Explicit

'-------------------------------------------------------------------------------
Public Sub Main()

' BX-24 serial port and LED demonstration.

Dim Toggle As Boolean

Toggle = True

Call Delay(0.5)

Do
If (Toggle) Then
' do somethin first time

End If
Toggle = Not Toggle

' Debug.Print '

Call BlinkLEDs
Call Delay(0.5)
Loop

End Sub
'-------------------------------------------------------------------------------
Private Sub BlinkLEDs()

Const GreenLED As Byte = 26
Const RedLED As Byte = 25
Const NewLED As Byte = 13

Const LEDon As Byte = 0
Const LEDoff As Byte = 1

' Red pulse.
Call PutPin(RedLED, LEDon)
Call Delay(0.07)
Call PutPin(NewLED, LEDon)

Call Delay(0.07)

' Green pulse.
Call PutPin(GreenLED, LEDon)
Call Delay(0.07)
Call PutPin(NewLED, LEDoff)
Call Delay(0.07)
Call PutPin(GreenLED, LEDoff)

Call Delay(0.07)
Call PutPin(RedLED, LEDoff)
Call Delay(0.07)
End Sub
'-------------------------------------------------------------------------------

Variables GreenLED and RedLED work, but NewLED does nothing. If you can download this code and it works, please tell me. It means I'm not the crazy one here, my microprocessor is.

2006-04-05T10:23:00.000-07:00

Well, yesterday I finally picked up a DB9 female/female cable, only to spend the better part of my day (afternoon class cancelled) trying to stop the repeat serial data errors I was seeing. After a while, I finally threw my hands up, and brought the cable to class today. No dice on the lab machines, nor with a different BX24, but a different cable worked just fine. Pretty ticked since I spent 15 bucks on what is probably the most important component only to waste a whole day and realize it's defective.

So, I'm borrowing a working cable for the time being. I have until Monday to create my project from nothingness, so today (thanks to another class cancellation) is Learn-BasicX-Day. Hopefully, my concept with solidify further once I start writing code.

2006-04-03T12:24:00.000-07:00

Here we go! This is my first ever online blog, created to track my progression through Physical Computing. I am currently mulling over some concepts for my blinky thing project. Right now, I am considering creating a variable light bar which responds to sound and/or ambient light. There is not too much else to report, I still need to acquire a few components (serial cable, light/sound sensors, dip switches) and familiarize myself with BasicX some more before I can finalize my concept and start construction. This will of course be a short process, since the final version of my project is due in one week.

Sadly, this will be a pictureless blog. I believe that I am one of the last technical students on earth not to own a digital camera or cameraphone of any sort. I will attempt to create some diagrams to try and illustrate critical points when they arise.

There will be more up as the concept materializes. Welcome!