setting port

[stan cartwright]

Hi. I used portd=portd and 0b11110011 instead of set portd.0 on:set portd.1 on:set portd.2 off:set portd.3 off
but it doesn't work. Flash hex works.
You can see the commented out code that worked.
Trying to set port in one go instead of setting bits.

  select case l_mot_pos
    case 4
      portd=portd and 0b11110011 ;set portd.0 on:set portd.1 on:set portd.2 off:set portd.3 off
    case 3
      portd=portd and 0b11110110 ;set portd.0 off:set portd.1 on:set portd.2 on:set portd.3 off
    case 2
      portd=portd and 0b11111100 ;set portd.0 off:set portd.1 off:set portd.2 on:set portd.3 on
    case 1
      portd=portd and 0b11111001 'set portd.0 on:set portd.1 off:set portd.2 off:set portd.3 on
  end select

  select case r_mot_pos
    case 4
      portd=portd and 0b10011111 ;set portd.4 on:set portd.5 off:set portd.6 off:set portd.7 on
    case 3
      portd=portd and 0b11001111 ;set portd.4 off:set portd.5 off:set portd.6 on:set portd.7 on
    case 2
      portd=portd and 0b01101111 ;set portd.4 off:set portd.5 on:set portd.6 on:set portd.7 off
    case 1
      portd=portd and 0b00111111 ;set portd.4 on:set portd.5 on:set portd.6 off:set portd.7 off
  end select
end sub

can a port be set like this?
if I can use portd=portd and var I could just rotate var left / right instead of case.
edit portd=portd and 0b00111111 would not set the bits to change
I got to change a nibble?

[Chris Roper]

Most ports have several registers, the generic names in GCBASIC being Port, LAT, and TRIS.

This is to prevent the "Read, Modify, Write" issue (Look it up - too complex to explain here) so whilst PortD = PortD AND 0b11110011 may have worked in ASM on eralyer AVR or PIC devices it is no longer supported by the hardware or the compiler.

Writing to PortD will actually write to LatD so your statement translates to:

LatD = PortD and 0b11110011

if any of the Port pins are pulled lower than 2.5V at the time of reading PortB then that bit in LatB will be set to Zero.

[stan cartwright]

Thanks. I'll leave the code as is.
Setting bits works ok but thought it looked inefficient.
I could not find how to set a port in help so should have guessed it was not possible and anyway you can not rotate 4 bits.

[Anobium]

Stan. Of course you can rotate four bits within a byte - but, it the key reading the byte variable/register, mask the bits you are not interested in, rotate and merge back. It may take more code to do this than a direct write (based on a case etc.).

But, it is doable.

[Anobium]

@Stan... before you ask - working code. It is full of serial debug for you. This will not be perfect but is shows how to mask etc.

  dim DeviceID as byte
  dim DeviceIDMask as byte
  do

    'Initial value - my assumption is that 0b11----11 where the 1 should not chang we rotate in the -'s


    DeviceID = 0b11000111  'this is same as DeviceID.2 = 1

    HSerPrintCRLF
    HSerPrint "BitWise Rotate"
    HSerPrintCRLF
    wait 100 ms

    Do

     'reset rotatation mask
      If DeviceIDMask.6 = 1 then
        DeviceID = ( DeviceID & 0b11000011 ) or 0b00000100
        HSerPrintCRLF 2
      end if


      HSerPrintCRLF
      HSerPrint ByteToBin( DeviceID )
      DeviceIDMask = DeviceID & 60 'same as 0b00111100
      Set C off
      Rotate DeviceIDMask Left
      DeviceID = ( DeviceID & 0b11000011 ) or DeviceIDMask

    Loop

  loop

Enjoy

[stan cartwright]

Thanks.. but if I can't set a port in one command then I would still be setting bits.
I think you could do it in picaxe.Probably thinking of when I used that.
Here is a problem with using and.
The interrupt is every 1ms and the sub increments a counter and when it gets to 20 resets and calls servo, which works
but the if millis and 1 = 0 then motors which I am using to test if millis is an even number ie 0,2,4,6,8,10 to 20 ie every 2ms
but motors does not get called.

dim millis as byte : millis = 0
    On Interrupt Timer0Match1 Call isr
    Dim OCR0  AS byte alias OCR0A
    Dim TCCR0 AS  byte alias TCCR0B
    WGM01 = 1
    OCR0 = 249 ;1ms
    TCCR0 = 0x28
    TCCR0 = TCCR0 or 0x03

;program

sub isr
  millis++
  if millis and 1 = 0 then motors ;every 2ms
  if millis = 20 then millis = 0 : servo ;every 20ms
end sub

[Anobium]

Stan ... the code is not real code. is it?

millis++ will throw an error
if millis and 1 = 0 then motors ;every 2ms not sure what this does or what the intent is
calling motors which may be a long running sub during the interrupt is bad practice. As the interrupt is now blocked.
servo will be called every interrupt.

So, not sure this code does anything meaningful. But, change to set flags in your main code to call motors and potentially servo.

[Chris Roper]

Why are you reinvrenting the wheel and not using the millis.h library?

[Anobium]

@Chris... that explains things... I assumed that Stan was using millis library.... hence, I was getting the error during millis++

The ISR wil fail the way is it structured. So, a rethink is required.

:-)

[stan cartwright]

Anobium and Chris. The interrpt is from gcb demos, 1ms. timer 0 match.
Anobium, I have the robot working with Chris Roper's millis BUT Chris has given me a modified version to test and is now working but Chris is a perfectionist and doesn't want it discussed until tested and finalised.
So I am trying to do the same with 1 interrupt.
the interruppt is every 1ms.
the motors sub I set a port bit on at the start of the sub and turned the port bit off at the end and scoped the port bit and measured the pulse width. It hovered around 8us.
the servo sub is just pulseout 220ms maximum.

Anobium,
"if millis and 1 = 0 then motors ;every 2ms not sure what this does or what the intent is"
It was to test if bit 0 of millis was 0 or 1.
If it was 0 then it is an even number ie 2,4,6...18,20 ms...millis increases by 1 every 1ms.
so every even number call motors
when millis gets to 20 it would call motors as it's an even number and reset to 0 and call servo after 20 1ms interrupts ie 20ms.

Anyway I got it to work by using an every 2ms interrupt and changing the isr sub.
so the motors not working previously must be if millis and 1 = 0 then motors.
I feel chuffed I got it working. Chris, it works the same as using your millis.h but I cannot post code
using that so "re-invented"your wheel :)
The robot uses a V53L0X rangefinder and I tweaked the obtacle avoidance code from old code and added a last_turn variable.

sub isr ,every 2ms
  motors
  mills = mills + 2
  if mills = 20 then mills = 0 : servo ;every 10 x 2 ms
end sub

[Chris Roper]

I have no objection to you posting or discussing the millis() function or code that uses it.

I was only asking that you don't publish code using the experimental DoEvery Statement.
I appreciate you beta testing it for me but, as I am still testing and optimising memory use on a range of devices so the syntax and use of DoEvery may change before I publish.

To show examples now may indirectly lock uys into a restrictive version in the future.

[stan cartwright]

Chris , I worked out my own doevery equivelant so I could post the code for the robot.
It is interchangeable, just comment out your doevery and use the interrupt or comment out the interrupt and use doevery.

[stan cartwright]

Anobium, please explain pulseout 2200 us.
It's software so the program stops for at least 2200us...yes?
So if I use an every 20ms interrupt no problem...yes?
If I also calling another event every 2ms ie within the pulseout 2200us what happens to the program flow.
It doesn't "seem" to be causing a problem.
Chris, this applies to using your code to.
Cheers stan

[Anobium]

PulseOut is a macro.

macro Pulseout (Pin, Time)
  Set Pin On
  Wait Time
  Set Pin Off
end macro

You can use every 20ms but ensure your interrupt does not use Wait as this will mess this up.
As Pulseout and therefore WAIT counts clock cycles (based on frequency) an interrupt of X cycles will impact PulseOut. The total number of clock cycles will be ( PulseOut cycles + X cycles in the interrupt ).

You will get 20 ms 'worth' of PulseOut clock transitions. So, this may be way is it working.

[stan cartwright]

Here's a video of the robot using 2ms interrupt. https://youtu.be/Y_ai0tc_rek

[stan cartwright]

Here's the program code. You can see it's working in the youtube video.
You can also see Chris Roper's millis doevery commented out. It looks promising doesn't it?
Chris has lost sleep working on this.
I was up until 2.30am thinking what would I do if I was the robot and an obstacle appeared...and coding the thoughts :)
Please check the motors sub. It looks a lot but take around 8us to execute....no way..
but I only got a Hantek 6022BE.
Just got a £8 salae clone logic analyser, as someone on the forum suggested from ebay. may be more accurate.
Ok if I post as a project with reference to Chris's millis removed?

;fullwave stepper V53L0X robot
#chip mega328p,16
#option Explicit
'#include "millis.h"

dir portc.0 out ;servo
dir portd.0 out:dir portd.1 out:dir portd.2 out:dir portd.3 out
dir portd.4 out:dir portd.5 out:dir portd.6 out:dir portd.7 out
;set up V53L0X
#define HI2C_DATA PORTC.5 ;sda portc.4 for nano portc.5 for uno
#define HI2C_CLOCK PORTC.4 ;scl portc.5 for nano portc.4 for uno
#define HI2C_BAUD_RATE 400
HI2CMode Master
;
;v53l0x software restart
HI2CStart
HI2CSend(0x52)
HI2CSend(0x89)
HI2CSend(0x01)
HI2CStop
wait 200 ms
;
dim l_mot_pos,r_mot_pos as byte
dim l_mot_dir,r_mot_dir as byte
dim servopos as Word
dim servodir,distance_lo,distance_hi,mindist,last_turn as Byte
;
#define distance distance_hi*256 + distance_lo ;v53l0x distance
#define forward 1   ;|
#define reverse 255 ;|--motor direction
#define stop 0      ;|
#define servopin portc.0
#define wasleft 1
#define wasright 0
;
last_turn = random and 1 ;0 or 1
servopos=1500 ;1.5ms servo mid position
servodir=1 ;servo rotation direction
mindist=200 ;minimum distance before avoiding
l_mot_pos=1:r_mot_pos=1
l_mot_dir=forward:r_mot_dir=forward
;
;set up interrupts
dim mills as byte : mills = 0
    On Interrupt Timer0Match1 Call isr
    Dim OCR0  AS byte alias OCR0A
    Dim TCCR0 AS  byte alias TCCR0B
    WGM01 = 1
;    OCR0 = 249 ;1ms
;    TCCR0 = 0x28
;    TCCR0 = TCCR0 or 0x03

    OCR0 = 124 ;2ms
    TCCR0 = 0x28
    TCCR0 = TCCR0 or 0x04

'#define DoEvery0  2, motors ;step motors every 2ms
'#define DoEvery1  20, servo  ; pulseout portc.0,servopos us ;50Hz servo 'refresh
'StartDoTimers
;
do ;main program
;check for objects and avoid
  getdistance ;any object too close?
  if distance <> 20 then ;20 means out of range so skip distance test
;distance to obstacle test
    if servopos > 1300 then ;not pointing right
      if servopos < 1700 then ;not pointing left
        mindist = 200 ;pointing forward min distance
      end if
    else
      mindist = 250 ; left and right min distance
    end if
;
    if distance < mindist then ;object close
      l_mot_dir=stop:r_mot_dir=stop ;stop motors
;
      if servopos > 1700 then
        turnright_until_clear ;object left
        last_turn = wasright
      else if servopos < 1300 then
        turnleft_until_clear ;object right
        last_turn = wasleft
      else ;obstacle forward
        if last_turn = wasright then ;turn right again
          turnright_until_clear
        else ;turn left again
          turnleft_until_clear
        end if
      end if
      l_mot_dir=forward:r_mot_dir=forward ;go forward
    end if
  end if
;
;rotate servo left-right
  if servodir = 1 then
    servopos = servopos +80
    if servopos = 2220 then
      servodir = 0
    end if
  else
    servopos = servopos - 80
    if servopos = 780 then
      servodir = 1
    end if
  end if
  wait 30 ms
loop
;end of main
;-----------------------------------------
sub isr
  motors
  mills = mills + 2
  if mills = 20 then mills = 0 : servo
end sub
;-------------------------
sub getdistance
  HI2CStart ;Sys V53L0X Range Start
  HI2CSend(0x52)
  HI2CSend(0x00)
  HI2CSend(0x01)
  HI2CStop

  HI2CStart ;read distance
  HI2CSend(0x52)
  HI2CSend(0x1e)
  HI2CReStart
  HI2CSend(0x53) ;set the read flag
  HI2CReceive(distance_hi)
  HI2CReceive(distance_lo, NACK) ;read one byte and conclude
  HI2CStop
end sub
;-----------------------
sub turnleft_until_clear
  do
   l_mot_dir=reverse:r_mot_dir=forward ;rotate anti clockwise
   wait 20 ms
   l_mot_dir=stop:r_mot_dir=stop
   getdistance
  loop until distance > mindist ;rotate left until clear
end sub
;-----------------------
sub turnright_until_clear
  do
   l_mot_dir=forward:r_mot_dir=reverse ;rotate clockwise
   wait 20 ms
   l_mot_dir=stop:r_mot_dir=stop
   getdistance
  loop until distance > mindist ;rotate right until clear
end sub
;-----------------------
sub motors
;left motor
  if l_mot_dir=stop then
    set portd.0 off:set portd.1 off:set portd.2 off:set portd.3 off
  else if l_mot_dir=forward then
    l_mot_pos++
    if l_mot_pos=5 then
      l_mot_pos=1
    end if
  else
    l_mot_pos---
    if l_mot_pos=0 then
      l_mot_pos=4
    end if
  end if
;
  select case l_mot_pos
    case 4
      set portd.0 on:set portd.1 on:set portd.2 off:set portd.3 off
    case 3
      set portd.0 off:set portd.1 on:set portd.2 on:set portd.3 off
    case 2
      set portd.0 off:set portd.1 off:set portd.2 on:set portd.3 on
    case 1
      set portd.0 on:set portd.1 off:set portd.2 off:set portd.3 on

  end select
;
;right motor
  if r_mot_dir=stop then
    set portd.4 off:set portd.5 off:set portd.6 off:set portd.7 off
  else if r_mot_dir=forward then
    r_mot_pos++
    if r_mot_pos=5 then
      r_mot_pos=1
    end if
  else
    r_mot_pos---
    if r_mot_pos=0 then
      r_mot_pos=4
    end if
  end if
;
 select case r_mot_pos
  case 4
    set portd.4 on:set portd.5 off:set portd.6 off:set portd.7 on
  case 3
    set portd.4 off:set portd.5 off:set portd.6 on:set portd.7 on
  case 2
    set portd.4 off:set portd.5 on:set portd.6 on:set portd.7 off
  case 1
    set portd.4 on:set portd.5 on:set portd.6 off:set portd.7 off
 end select
end sub
;----------------------------
sub servo
  pulseout servopin,servopos us
end sub

[stan cartwright]

The idea that
sub isr
motors
mills = mills + 2
if mills = 20 then mills = 0 : servo
end sub
works was inspired by Chris Ropers's doevery a la amstrad basic I suggested to him.
I can see how he is doing it but not from his code which I find difficult to understand.
The sub isr could have various counters to different timed subs....groovy

[Chris Roper]

What is needed here is the second User Interrupt function in the Do suite that I have been working on:

Set Pin On
DoAfter 20 Set Pin Off

Would perform the same function as

Pulseout (Pin, 20 ms)

But it would not use the Wait command and be 100% compatible with other interrupts as it is itself an interrupt.

BUT, that is part of the Library I am working on so is not yet ready for testing, hang in there Stan, the more I understand of your needs the more I can refine my thinking.

I will give it priority and try and get you some test code in the next couple of days.

[stan cartwright]

Chris , you are making me feel guilty.
I have a hardware solution if I want from Mr Kent..very complicated but nice offered.
I don't get using wait..the interrupt still works.
That's how I use the robot- r_mot_left=forward : wait 200ms and the motors still turn.

Set Pin On
DoAfter 20 Set Pin Off

Would perform the same function as

Pulseout (Pin, 20 ms)

But it would not use the Wait command and be 100% compatible with other interrupts as it is itself an interrupt.

It's pulseout pin,2ms and would be variable from 500 us to 2500 us. 1500us centres a servo.
I think to simulate pulseout would need a every 10us interrupt.
I've used a servo interrupt before and a stepper motor interrupt before but not together
off 1 interrupt before. smug

[stan cartwright]

Chris, I don't know why a servo needs pulseing it's position every 20msjust what I found researching.
I think it's for like if the servo is under strain eg a model plane's rudder driven by a servo and the wind resistance.
In my robot code the servo is not under stress so I removed the call to servo in the every 2ms isr
and pasted the contents of the servo sub at the end off the only code that controls the servo and
it is all working fine as before. The every 2ms interrupt is still needed for the motors to perform at peak speed and torque.

;rotate servo left-right
  if servodir = 1 then
    servopos = servopos +80
    if servopos = 2220 then
      servodir = 0
    end if
  else
    servopos = servopos - 80
    if servopos = 780 then
      servodir = 1
    end if
  end if
  pulseout servopin,servopos us ;this WAS interrupt driven every 20ms
  wait 30 ms 'to allow servo to move slower and not overheat and getdistance to work

Hope your millis is working to plan.
would doafter be
get millis store as mil1
do event
is after=millis-mil1
checked in an interrupt often

[Chris Roper]

To avoid further confusion:

Millis() is working fine and it has been working and included in GCBASIC for a few years now.
Millis() Uses Timer0 and a Long Variable to count the number of milliseconds since a device reset.

You were looking for an easy way to have user based timer interrupts, but as Timer0 was already used by the Millis any code that tried to use Timer0 would disrupt Millis.

What I have been working on is a way to share Timer0 between the existing Millis() function and the new requirement for a user based timer interrupt. As "millis.h" already has all of the code to set up Timer0 on all of the supported devices I used that initialisation code as the basis of the new user interrupts.

The new system is NOT using the millis() function nor does it alter the millis() function in any way you, and anybody else, can continue to use millis() in their code exactly as they always have. The Modified millis.h that I sent you just give an extra hook into the interrupt to allow DoEvery and millis() to coexist without conflicting over timer0.

The help and the example libraries along with any Arduino Documentation contain info on the use of millis().

The new functions are taking time because they have to be designed to work on many different devices and minimise the amount or RAM use, that takes time to design, test and rework the retest for several devices. They are NOT based on Millis() they are independent Methods.

The original Beta code I sent you was specific to your need - the resultant library will be generic.

So the bottom line is that I am NOT working on or with millis - this is a totally separate project to millis but will coexist with millis so that they can share Timer0.

So please USE millis(), do NOT try to create your own millis() function, millis() works now, it has worked for a few years and it has been extensively tested on hundreds of different devices.

DO NOT reinvent the wheel - the DoEvent Library, for want of a better name, is what I am working on, NOT millis() and as the wise man said “if it ain't broke, don't fix it”.

[stan cartwright]

Chris-It's just a hobby. I can wait for for your ideas to be published.
More I experiment,more I learn. So... sorry. I will keep on experimenting with interrupt driven events for my own interests on a 328p or a 18f25k22, all I use.
Your doevery will be useful for making interrupts easier.
Hope the project works out.