DRO Z-Axis /4th axis "combiner"

//Part 2

void loop() {

pos1 = scale1.read();

pos2 = scale2.read();

delt2 = pos2 - oldpos2;

delt1 = pos1 - oldpos1;

delt = delt2 - delt1;

while (delt > 0) {

if (outA == LOW && outB == LOW) { //if 9 is low and 8 is low

PORTH = B00100000; //push 8 high & 9 low

outB = HIGH;

delt--;

}

else if (outA == LOW && outB == HIGH) { //if 9 is low and 8 is high

PORTH = B01100000; //leave 8 high, Push 9 high

outA = HIGH;

delt--;

}

else if (outA == HIGH && outB == HIGH) { //if 9 is high and 8 is high

PORTH = B01000000; //push 9 high & 8 low

outB = LOW;

delt--;

}

else if (outA == HIGH && outB == LOW) { //if 9 is HIGH and 8 is LOW;

PORTH = B00000000; //leave 8 LOW push 9 low

outA = LOW;

delt--;

}

}

while (delt < 0) {

if (outA == LOW && outB == LOW) { //if both are low,

PORTH = B01000000; //leave 8 low, Push 9 high

outA = HIGH;

delt++;

}

else if (outA == LOW && outB == HIGH) { //if 9 is low and 8 is high;

PORTH = B00000000; //push 8 low, Leave 9 LOW

outB = LOW;

delt++;

}

else if (outA == HIGH && outB == LOW) { //if 9 is high and 8 is low;

PORTH = B01100000; //push 8 high, Leave 9 HIGH

outB = HIGH;

delt++;

}

else if (outA == HIGH && outB == HIGH) { //if 9 is high and 8 is high;

PORTH = B00100000; //leave 8 high, Push 9 LOW

outA = LOW;

delt++;

}

}

oldpos1 = pos1;

oldpos2 = pos2;

}

Can these units have one scale at one rate, ie a 1um unit combined with a 5um scale , outputting a 5um position ? or a 5um scale mixed with a 10um scale outputting a 10um position.?

Is this possible?

Thanks Neil

In principle, yes. I think you would need to work (store) internally in the finer units, incrementing or decrementing by 1 when the fine scale changes and incrementing or decrementing by 5 or 10 when the coarser scale changes. It is the delt++ and delt-- lines above - they need slight modifications. 50% of them will be unchanged.

Then you would have to write a little bit of extra code that takes the number above and rounds it to the nearest graduation of your desired output, pondering over the situation where the value ends in 5 for the 10um position.

There may be an issue with the code above in that it does not cover the case where delt=0, only doing something when it is greater or less than zero.

Getting the output to 10micron should simply be a case of setting how many decimal places the display shows which most of them can do so you just set it to 2 decimal places rather than 3 which shows the 5 at the end.

This has been a very interesting thread (for me) to follow, and I would like to make a suggestion - instead of using the Arduinos, which run at 16 MHz, try using an ESP32, which runs at up to 240 MHz. They are also usually even cheaper than Arduinos, but can be programmed using the Arduino IDE, or PlatformIO.

I went this route after I had a timing problem on a project, and now always use the ESP32. It also has a WiFi and BlueTooth interface built-in, so its very easy to add remote controls if required. It also has a much bigger memory space, so larger, more comprehensive programs are possible. They can be used with all the usual Arduino modules.

There is plenty of information online - I found this site very helpful when I first started using them:

LINK1

and also this:

LINK2

Many others if you search ESP32

Re the comments on which bootloader to use, and connecting to Arduino NANOs or UNOS. In the Arduino IDE 'Tools' menu is an option to 'Get Board Info' - if the Arduino is connected Ok, then clicking this will show a small window giving (IIRC) the board Serial number and other information - this doesn't appear if there is a connection problem - AFAIK this is the quickest way to know whether your particular board is connected without having to upload a sketch. Note the comments other have made regarding the 'Use Old Bootloader' option.

spelling edit

Edited By An Other on 25/04/2022 09:06:45

I have heard that there is difficulty getting hold of any of the Arduino or Raspberry pi due to the computer chip shortage.

Loads on ebay, but price has increased markedly over past year or so