Your advice please
GMACD53
Posts: 10
I am very new to this field but do come from a PLC Ladder Programing / Relay Logic background.
I have written a PLC Ladder Program for a project which I have not built because it required a lot of sensors (some of which are not practical to mount) for a relatively simple task.
I had a hunch that with the right hardware this project could be greatly simplified.
My hunch was half right when I discovered Ping))) Laser sensors in that the hardware aspect is much simpler but Stamp Basic and Blockly are a bit daunting at this stage.
This project involves 4x LaserPing sensors, Microcontroller and 4x Relays for interfacing to another control.
My question is two-fold...
1) Is someone interested in doing this project for me terms negotiable?
Bearing in mind it has commercial potential especially if a corded or wireless remote is added replacing the dumb controller that is being sold today.
2) Failing the above what is the best Microcontroller and what do I need to get this project off the ground.
Note: I am a Mac OS Yosemite user.
I am having an attempt to learn BrocklyProp so please take a look at my Test by GMACD53 and comment...
Any advice greatly appreciated!
Regards
Guy
I have written a PLC Ladder Program for a project which I have not built because it required a lot of sensors (some of which are not practical to mount) for a relatively simple task.
I had a hunch that with the right hardware this project could be greatly simplified.
My hunch was half right when I discovered Ping))) Laser sensors in that the hardware aspect is much simpler but Stamp Basic and Blockly are a bit daunting at this stage.
This project involves 4x LaserPing sensors, Microcontroller and 4x Relays for interfacing to another control.
My question is two-fold...
1) Is someone interested in doing this project for me terms negotiable?
Bearing in mind it has commercial potential especially if a corded or wireless remote is added replacing the dumb controller that is being sold today.
2) Failing the above what is the best Microcontroller and what do I need to get this project off the ground.
Note: I am a Mac OS Yosemite user.
I am having an attempt to learn BrocklyProp so please take a look at my Test by GMACD53 and comment...
Any advice greatly appreciated!
Regards
Guy
Comments
If you have a PLC background, I'm surprised Blocky is daunting ?
That's a bit vague - what is the interface to another controller - is that via relay contacts only ?
My guess is Blocky supports Laser ping examples, did you try those ?
The PLC’s I have programmed used Ladder Programming which is nothing like Blockly.
Can you write out step by step what you need the program to do and a how everything needs to be hooked up.
Have you ever used BASIC?
4x PingLaser sensors to monitor the position of 4x motor driven legs.
The Microcontroller to control 4x Relays to supply or interrupt power to the motors.
The supply or interruption depending on...
Extended Limit reached (Programable)
Retracted Limit (Programable)
Platform is level (Programable)
The Programable aspect with a Parallax 5 position switch...
When the following are set by driving the legs manually to limit positions then operate switch to set limits...
SWITCH NOT PRESSED
Forward/Left = Left Front Retracted Limit
Forward/Right = Right Front Retracted Limit
Back/Left = Left Back Retracted Limit
Back/Right = Right Back Retracted Limit
SWITCH PRESSED
Forward/Left/Pressed = Left Front Extended Limit
Etc Etc
Centre/Pressed = Platform is Level
Microcontroller to keep platform level by controlling supply to the motors via 4x relay normally closed contacts.
This would be done by keeping the legs proportionally in sync relative to their Platform Level position.
To maintain the platform level the legs must travel the same distance as each other at all times (in practice this will have to have a tolerance built in).
While the legs are retracting or extending if one is faster than the others then stop it until the others catch up.
If say both the Left Hand legs ran faster then the platform would not be level side to side so stop until the Right Hand legs catch up.
Another thing to bear in mind is what tolerance to employ so the motors are not switching too much. I think probably between 5-10 mm?
The idea is 4 Ping))) sensors will replace 8 limit switches and the need for a level sensor plus it takes care of one leg lifting off the ground by retracting faster than the others which increases the load on the opposite legs.
My idea is that once the Microcontroller has been told where the limits are and where the legs are when the platform is level it can control the leg motors at their limits or they are out of sync.
Once a limit is reached then stop driving that leg and stop the others when in sync or their limit reached.
This stop action should be long enough (5 secs) for the operator to release the retract or extend button connected to the main control. This allows for operation in the opposite direction if required.
In a nutshell I need to monitor and control 4x motor driven legs for their expanded limit, retracted limit and keep them in sync relative to their Platform Is Level starting point which often has the legs at different lengths.
I hope this makes sense to you.
What distance can these sensors be from the controller?
Can they be weather proofed and still functional?
Did you try and get any Blocky program running ?
eg this one uses Ping sensors (ultrasonic)
https://learn.parallax.com/tutorials/language/blocklyprop/parking-assist-blocklyprop-project
The function used, looks to work with either Ping sensor
https://learn.parallax.com/support/reference/propeller-blocklyprop-block-reference/sensor/ping-distance
Some of it I understand but still not sure if I can design a program for my application from scratch.
I have not invested in anything yet as I am still trying to determine which way to go and if I am capable.
That's why you make it easier, by taking something that already uses the modules you want to use, and modify that
A FLiP module and laser Pin module will not cost a lot.
You likely need to qualify the laser ping will actually work physically in your application. Being optical, they have some caveats on background & targets.
eg I recall claims in other threads they do not work well outdoors.
I will take a look at the Flip and maybe will have to experiment with a Ping))) Laser.
a relevant example of PropBASIC is
https://github.com/parallaxinc/PropBASIC/blob/master/example/Ping.pbas
I do like the FLiP!