CivicTsi

First, no one wants to buy a CAN bus converter to communicate with it. Second, the engineers that programmed it don't wont to spill the beans on what commands to send it.

CivicTsi

If anyone's curious, here's my program; or at least what I have so far. I'm sure the values will have to be changed once installed. Servo position 150 in stopped. 100 is max reverse. 200 is max forward.

setfreq m8
servo 2,150
servopos 2,132
pause 1000
servopos 2,150
pause 50
readadc 0,b5
servopos 2,168
pause 1000
servopos 2,150
pause 50
readadc 0,b6
readadc 2,b1
main:
readadc 0,b0
readadc 2,b1
if b1 > 71 then gosub pos1
if b1 > 74 then gosub pos2
if b1 > 77 then gosub pos3
if b1 > 80 then gosub pos4
if b1 > 83 then gosub pos5
if b1 > 86 then gosub pos6
if b1 > 89 then gosub pos7
if b1 > 92 then gosub pos8
if b1 > 95 then gosub pos9
if b1 > 98 then gosub pos10
if b1 > 101 then gosub pos11
if b1 > 104 then gosub pos12
if b1 > 107 then gosub pos13
if b1 > 110 then gosub pos14
if b1 > 113 then gosub pos15
if b1 > 116 then gosub pos16
if b1 > 119 then gosub pos17
if b1 > 122 then gosub pos18
if b1 > 125 then gosub pos19
if b1 > 128 then gosub pos20
if b1 > 130 then gosub pos21
if b0 < b2 then goto open
if b0 > b3 then goto close
servopos 2,150
pause 50
readadc 0,b0
readadc 2,b1
let b4 = b0 - b2 + 100
goto main
open:
readadc 0,b0
readadc 2,b1
let b4 = b0 - b2 + 100
if b4 > 60 then goto fineopen
servopos 2,168
goto main
close:
readadc 0,b0
readadc 2,b1
let b4 = b0 - b2 + 100
if b4 < 140 then goto fineclose
servopos 2,132
goto main
fineopen:
servopos 2,160
goto main
fineclose:
servopos 2,140
goto main
pos1:
let b2 = 40
let b3 = b2 + 4
return
pos2:
let b2 = 50
let b3 = b2 + 4
return
pos3:
let b2 = 60
let b3 = b2 + 4
return
pos4:
let b2 = 70
let b3 = b2 + 4
return
pos5:
let b2 = 80
let b3 = b2 + 4
return
pos6:
let b2 = 90
let b3 = b2 + 4
return
pos7:
let b2 = 100
let b3 = b2 + 4
return
pos8:
let b2 = 110
let b3 = b2 + 4
return
pos9:
let b2 = 120
let b3 = b2 + 4
return
pos10:
let b2 = 130
let b3 = b2 + 4
return
pos11:
let b2 = 140
let b3 = b2 + 4
return
pos12:
let b2 = 150
let b3 = b2 + 4
return
pos13:
let b2 = 160
let b3 = b2 + 4
pos14:
let b2 = 170
let b3 = b2 + 4
return
pos15:
let b2 = 180
let b3 = b2 + 4
return
pos16:
let b2 = 190
let b3 = b2 + 4
return
pos17:
let b2 = 200
let b3 = b2 + 4
return
pos18:
let b2 = 210
let b3 = b2 + 4
return
pos19:
let b2 = 220
let b3 = b2 + 4
return
pos20:
let b2 = 230
let b3 = b2 + 4
return
pos21:
let b2 = 240
let b3 = b2 + 4
return

Skylar

Cheers CivicTsi. Can you rename some things to make it easier to read or just format it with tabs and blank lines? and what is b3?

Skylar

Here's my real simple bit of code, it's not all there, just the algorithm to control the servo.

sweeptime = 100 '100ms
Pulsout outpin, sweeptime 'move servo to one side
start:
ADCIN 2, psi 'check boost level on adc channel2 and save to psi
if psi>target then 'compare target to current boost level
sweeptime = sweeptime + 5 'increase servo opening position adds 5ms to sweeptime
pulsout outpin, sweeptime 'output position to servo
pause 15 'pause for servo's sake
goto start 'start all over
else
pulsout outpin, 100 'if boost's below target shut VGT
endif
pause 15 'pause for servo's sake
goto start 'start all over

Shutting the VGT might be a bit to quick and I might need to gradually shut it the same way it opens. I'm thinking with a servo, it won't need continuous self correction/position monitoring in the code because servos should go to their position and hold it. I know some servos hold and some don't and if the servo I have doesn't hold, it gets updated quickly enough (50-60 times a sec) to hopefully not make a difference. I haven't written it yet but I know I need to cap sweeptime to 200 so the servo don't try to break itself.

CivicTsi

Sure, I can go through with an explanation. I will a little later today when I have more time. As for the variables:

b0=Pot position
b1=Map sensor
b2=The position desired
b3= The position desired plus a little more, giving it an acceptable range to be in.
b4=The difference between b0 and b2
b5=The Pot position when vane is fully closed after initital startup.
b6=The Pot position when vane is fully open after initital startup.

More to come later..

CivicTsi

What PIC are you using? Also, good luck finding a suitable servo that costs a decent amount of money. All the ones I've seen are either way too weak, or are ridiculously expensive.

CivicTsi

setfreq m8 'Set PIC frequency to 8Mhz
servo 2,150 'Activate servo control
servopos 2,132 'Close Vane
pause 1000
servopos 2,150 'Stop Vane
pause 50
readadc 0,b5 'Take position reading and save to memory block b5
servopos 2,168 'Open Vane
pause 1000
servopos 2,150 'Stop Vane
pause 50
readadc 0,b6 'Take position reading and save to memory block b6
readadc 2,b1 'Take MAP sensor reading and save to memory block b1
main:
readadc 0,b0 'Take position reading and save to memory block b0
readadc 2,b1 'Take MAP sensor reading and save to memory block b1
if b1 > 71 then gosub pos1 'If MAP sensor is greater than 71 then temporarily goto pos1, etc.
if b1 > 74 then gosub pos2
if b1 > 77 then gosub pos3
if b1 > 80 then gosub pos4
if b1 > 83 then gosub pos5
if b1 > 86 then gosub pos6
if b1 > 89 then gosub pos7
if b1 > 92 then gosub pos8
if b1 > 95 then gosub pos9
if b1 > 98 then gosub pos10
if b1 > 101 then gosub pos11
if b1 > 104 then gosub pos12
if b1 > 107 then gosub pos13
if b1 > 110 then gosub pos14
if b1 > 113 then gosub pos15
if b1 > 116 then gosub pos16
if b1 > 119 then gosub pos17
if b1 > 122 then gosub pos18
if b1 > 125 then gosub pos19
if b1 > 128 then gosub pos20
if b1 > 130 then gosub pos21
if b0 < b2 then goto open 'If actual position is less than desired position, open vane.
if b0 > b3 then goto close 'If actual position is more then desired position plus 4, than close vane
servopos 2,150 'stop vane
pause 50
readadc 0,b0 'Take position reading and save to memory block b0
readadc 2,b1 'Take MAP sensor reading and save to memory block b1
let b4 = b0 - b2 + 100 'make b4 show the difference between actual and desired position plus 100 to prevent overflow
goto main
open:
readadc 0,b0 'Take position reading and save to memory block b0
readadc 2,b1 'Take MAP sensor reading and save to memory block b1
let b4 = b0 - b2 + 100 'make b4 show the difference between actual and desired position plus 100 to prevent overflow
if b4 > 60 then goto fineopen 'if within 40 of desired position, open at slower speed.
servopos 2,168 'open vane
goto main
close:
readadc 0,b0 'Take position reading and save to memory block b0
readadc 2,b1 'Take MAP sensor reading and save to memory block b1
let b4 = b0 - b2 + 100 'make b4 show the difference between actual and desired position plus 100 to prevent overflow
if b4 < 140 then goto fineclose ''if within 40 of desired position, close at slower speed.
servopos 2,132 'close vane
goto main
fineopen:
servopos 2,160
goto main
fineclose:
servopos 2,140
goto main
pos1:
let b2 = 40 'Make desired positon 40, etc
let b3 = b2 + 4 'Make the desired position plus 4 the highest acceptable tolerance for position
return
pos2:
let b2 = 50
let b3 = b2 + 4
return
pos3:
let b2 = 60
let b3 = b2 + 4
return
pos4:
let b2 = 70
let b3 = b2 + 4
return
pos5:
let b2 = 80
let b3 = b2 + 4
return
pos6:
let b2 = 90
let b3 = b2 + 4
return
pos7:
let b2 = 100
let b3 = b2 + 4
return
pos8:
let b2 = 110
let b3 = b2 + 4
return
pos9:
let b2 = 120
let b3 = b2 + 4
return
pos10:
let b2 = 130
let b3 = b2 + 4
return
pos11:
let b2 = 140
let b3 = b2 + 4
return
pos12:
let b2 = 150
let b3 = b2 + 4
return
pos13:
let b2 = 160
let b3 = b2 + 4
pos14:
let b2 = 170
let b3 = b2 + 4
return
pos15:
let b2 = 180
let b3 = b2 + 4
return
pos16:
let b2 = 190
let b3 = b2 + 4
return
pos17:
let b2 = 200
let b3 = b2 + 4
return
pos18:
let b2 = 210
let b3 = b2 + 4
return
pos19:
let b2 = 220
let b3 = b2 + 4
return
pos20:
let b2 = 230
let b3 = b2 + 4
return
pos21:
let b2 = 240
let b3 = b2 + 4
return

Turboedmav

How about using a linear actuator attached to the compressor housing and linked to the VGT arm? They have amazing push/pull forces... I don't think they are that sensitive to high temps as servos seem to be... and if getting the vgt from position "x" to position "y" in less than a second is not really critical... then they could help... couldn't they? (they are on the slow side in terms of actuation speed but compensate with strength)

Those things can lift tens, hundreds and even thousands of times their own weight and would somehow prevent rack seizure by applying generous amounts of force to move the whole thing back and forth... are they overly expensive? Are they readily available in the RC/hobby/DIY robotics world? Do they generate position feedback?

I'm only thinking aloud here... forgive my noob status with these things... I wish I knew how to tinker with microcontrollers myself... damn!... I better get started now... Skylar... I'll take you on that offer to point me in the right direction... from the little stuff I've read, there seems to be a hot debate over which PIC is better for what: Picaxe: Great as an educational tool and easy to program, Arduino: Great variety of "shields" (pre-assembled boards with functions like FM trasreceiver, GPS, bluetooth, etc) and generic PICs: Which from what I understand are tougher to program cause they run on assembler code... honestly, I dont even know if what I've just writen here will make any sense...

Can you mention a few books to get me started on microcontrollers? I bet there's a "Microcontrollers for dummies" ... lol...

CivicTsi

Good idea. I've previously researched it and have seriously considered using a linear actuator. However, I found that the cost of a suitable one would run in between $150-200 Dollars (U.S.). There also is the hassle of trying to mount it. Using a Picaxe and an ESC is barely $50.
As for learning how to program a PIC, it's not that hard. 6 months ago I couldn't even tell you what a PIC was. Do what I did and read the manual. Using the program examples in the manual helped a lot. As for Arduino vs. Picaxe, I have no idea which one is better or easier. I think they will both do what you want them to do though.

CivicTsi

I'm still working on the PWM route to control the factory electronics. No success yet. I'm doubting more and more that this thing is preprogrammed to additionally accept PWM. I'll give it a few more tries at varying pins and frequencies then I'm just going to concentrate on installing and tuning the system I made. As for boost control, it seems that other people who've put this turbo on gasoline engines have had to install an additional wastegate. I wonder if this is really needed. Perhaps people didn't have the vanes open the whole way in order to decrease boost. Anyone have personal experience with this?