CNC Hand Pendant project

HI all, I am looking to build a hand pendant controller for my CNC machine. I need to ask IF it is possible to do what I need. It will need to use the following components as a unit.

4x4 or 3x3 keypad
2 rotary encoders 10-16 count
joystick
4x20 lcd display Blue/white
RS485 com
2 extra buttons

Can all of this be made to work as a unit?? Would it be small enough to fit in a hand instrument case ?

Is there a place where I can buy all of this at one spot ?

Thanks For your Time, (:wink: TP

PendantDesign.jpg

Can all of this be made to work as a unit?

Yes why not?

Would it be small enough to fit in a hand instrument case ?

I would have thought so.

Is there a place where I can buy all of this at one spot ?

I would try Farnell.

Well I know exactly ZERO about an Arduino and what it can or cannot do (:wink: So before I jump into something that cannot be done I thought I would ask for advice from people that might know.

(:wink: TP

Well the Arduino can do it. However what you need to find out is how it can output an extra control signal into your CNC setup. It could be your CNC that stops you completing your project.

I would go with a 200 count or maybe 100 count encoder.

there are a lot of people who offer these type of pendants.

once you get the bits workin, here is a tip.
when looking at the encoder, only, specifically and ONLY look at 'now'
do not try to count every step then store it, then move the motor.

allow for someone to 'fling' the wheel around so it spins around 20 times....
allow it to miss steps wen they are too fast. IGNORE THEM.

this way, wen the operator stops the wheel, regardless of how many steps were sent previously, the stop of the dial will stop the motors.

the operator can then 'fling' for a rapid, but the machine only move at it's proper speeds,
all extra values are ignored
and the operator can move the dial slowly at low speed to move under a more controlled input.

HI, The encoders are not for motion. They are to adjust feedrate and spindle speed. The thumbstick will be for motion.

Just a better rundown .

The thumb stick will be to jog around the table to do setups. The 2 rotary encoders will be for setting the Spindle speed override and the feed rate override so the 10-16 counts per rev is fine.

The 4x20 display is to see the axis positions and a few messages.

The keypad is for doing functions.

The pendant will talk to the PC via the RS485 com.

Interfacing to the PC side will NOT be a problem as it talks Modbus very well.

I really need to know what arduino unit to buy so there will be NO TIME LAG in functions. Will a lower powered unit do the job or do I need one of the higher powered models and is there enough of the right kind of I/O to do what I need to do.

Thanks for the Time, (:wink: TP

I really need to know what arduino unit to buy so there will be NO TIME LAG in functions.

No processor on the planet will give you no lag time. If that is a requirement then it is impossible. I suspect you do not mean that.

You are correct I should have stated as little lag time as possible.

(:wink: TP

Vmax549:
You are correct I should have stated as little lag time as possible.

(:wink: TP

Yes we are engineeres here so we take things literally.
Any Arduino will give you unnoticeable lag, go go for the Uno or the Micro if you want it smaller.

the lag time has a LOT to do with how well you write yoru program and what you want to do.

I can guarantee that you WILL notice a huge lag time when you light an LED like this

digitalWrite(led,LOW);
delay(32000)
digitalWrite(led.HIGH)
delay(32000)

however the general Arduino scans so much faster than you can perceive, that for all intene an purpose there will be no way you will ever see any delay.

for S & G, I will write a simple sketch

long count

if (switch == HIGH)
count = count++

then test my switch to see how low I can flick the switch to see what the count it.

if(switch2==HIGH)
print line(count)

maybe it will show how many scans a human of my age can flick that switch.