Scratch

SimpleScratch · 2012-07-20 04:48:39

I've managed to bodge together a RaspberryPi, a Mesh enabled Scratch mod and a Python message handler to bridge between Scratch and the GPIO pins.

To make life easy for others I thought it would be great if Scratch could be modded to not only enable Mesh,, but to launch a host session and also launch the python handler script so all a user would have to do would be connect hardware to the GPIO and run the modded Scratch.

Is it possible and is someone up for it? smile

Simon

blob8108 · 2012-07-20 06:41:04

Is it easier to use Remote Sensor Connections? You could mod Scratch to enable them by default; and then write a small shell script to launch the python script and then the Squeak VM.

It only has to work on Linux, right?

SimpleScratch · 2012-07-20 13:20:05

What is the difference between Mesh and Remote Sensor Connections?
Simon

blob8108 · 2012-07-20 15:32:17

They implement the same protocol, but one might be easier to enable by default.

I think once enabled, remote sensor connections automatically start listening on the RSC port. Then Python could just connect to the socket. smile

SimpleScratch · 2012-07-21 03:03:10

Ok - learning fast here - seems RSC is just a local machine version of Mesh - my Python handler program seems to work with normal Scratch with RSC enabled just as well as using a modified Scratch with Mesh enabled smile

And - even better - if I've enabeld RSC and saved a project - RSC is restarted when I load the project smile

That will do me for the moment - might need to come back to auto-launching my python GPIO handler script later smile

Simon

johnnydean1 · 2012-07-21 04:20:30

RSC is local mesh, and mesh is over a network. However when mesh is used its handled by RSC (On each client).

If you want to think about it like this:
RSC is all external I/O in Scratch.
Mesh acts like a new "sensor" and allows connections to other devices.

Last edited by johnnydean1 (2012-07-21 04:21:48)

bobbybee · 2012-07-21 06:44:19

I can write this for you, I'm working on something similar right now.

Magnie · 2012-07-21 10:17:06

Remote Sensor Connections is "basically" hosting a Mesh network on Scratch, since both hosting and enabling RSC does the same thing. All Mesh does, is make it so you can directly connect with another computer without needing to program it yourself or create a proxy.

For what you want to do, is look for a SmallTalk command that runs OS commands (i.e. "python script.py"). https://www.google.com/search?q=smallta … l+commands

SciTecCf · 2012-07-21 10:31:38

Magnie wrote:
Remote Sensor Connections is "basically" hosting a Mesh network on Scratch, since both hosting and enabling RSC does the same thing. All Mesh does, is make it so you can directly connect with another computer without needing to program it yourself or create a proxy.

For what you want to do, is look for a SmallTalk command that runs OS commands (i.e. "python script.py"). https://www.google.com/search?q=smallta … l+commands

Magnie talk gives me the dumb. o.e

Kiddin'. Thanks Magnie! Very useful stuff.

blob8108 · 2012-07-21 13:11:18

SimpleScratch wrote:
if I've enabeld RSC and saved a project - RSC is restarted when I load the project

That will do me for the moment - might need to come back to auto-launching my python GPIO handler script later

Great! smile

I still think the easiest way is to write a shell script that runs the Python script in the background (isn't the syntax something like "python gpio.py &" ?) and then launches Scratch/the Squeak VM.

SimpleScratch · 2012-07-26 14:28:35

My main problem at the moment is that my python program needs to "hear" Scratch talking to it when it launches so I need to launch Scratch with RSC enabled before launching my python script.

I've sorted launching Scratch with RSC enabled by creating a blank project (called /home/pi/Scratch/rsc.sb smile ) and I've made a new desktop shortcut (called ScratchRSC smile ) that execs "scratch --document /home/pi/Scratch/rsc.sb" - so nearly there now without having to mod Scratch itself smile

I'm off to play with the Python script smile
For info - this is where I'm at now
http://cymplecy.wordpress.com/2012/07/20/how-i-got-scratch-talking-to-my-raspberry_pi/

blob8108 · 2012-07-26 15:03:50

Don't you just need to try connecting several times until you're successful? Perhaps wrap the "create socket" call in a while loop, or something.

Perhaps then you can modify your desktop shortcut to read something like

scratch --document /home/pi/Scratch/rsc.sb; sudo python scratch_gpio_handler.py

Or even add a "wait" command, like

scratch --document /home/pi/Scratch/rsc.sb; wait 10; sudo python scratch_gpio_handler.py

Last edited by blob8108 (2012-07-26 15:04:42)

SimpleScratch · 2012-08-12 21:35:26

Things are progressing - the python program is a lot less CPU intensive (a bit more sleeping in loops than before smile )

Its easy (I now know) to launch a python prog and then Scratch in one script (and the python program just waits for RSC to be enabled now so thats sorted)
http://cymplecy.wordpress.com/2012/07/20/how-i-got-scratch-talking-to-my-raspberry_pi/
gives upto date info - just looking into the other problems at the moment sad
http://scratch.mit.edu/forums/viewtopic.php?id=103605

Scratch

archived forums

#1 2012-07-20 04:48:39

A mod to launch RaspberryPi python handler

#2 2012-07-20 06:41:04

Re: A mod to launch RaspberryPi python handler

#3 2012-07-20 13:20:05

Re: A mod to launch RaspberryPi python handler

#4 2012-07-20 15:32:17

Re: A mod to launch RaspberryPi python handler

#5 2012-07-21 03:03:10

Re: A mod to launch RaspberryPi python handler

#6 2012-07-21 04:20:30

Re: A mod to launch RaspberryPi python handler

#7 2012-07-21 06:44:19

Re: A mod to launch RaspberryPi python handler

#8 2012-07-21 10:17:06

Re: A mod to launch RaspberryPi python handler

#9 2012-07-21 10:31:38

Re: A mod to launch RaspberryPi python handler

Magnie wrote:

#10 2012-07-21 13:11:18

Re: A mod to launch RaspberryPi python handler

SimpleScratch wrote:

#11 2012-07-26 14:28:35

Re: A mod to launch RaspberryPi python handler

#12 2012-07-26 15:03:50

Re: A mod to launch RaspberryPi python handler

#13 2012-08-12 21:35:26

Re: A mod to launch RaspberryPi python handler

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