Odd results from connecting two propellors
DiverBob
Posts: 1,108
in Propeller 1
I connected 2 propeller boards together through a single wire. One prop is configured as an output and the other as an input. The output prop is showing programmatically that the output is changing but the input prop pin is not registering the change. This is a relatively slow changing output and although both props run at different oscillator speeds, this should not make a difference. I tried using a resistor to ground on the line but that didn't make a difference. I have verified multiple times that the ports are both configured properly. I ran out of ideas of what to check for?
Comments
-- common ground?
-- bad connection?
You might try putting a pull-up on the input, and then control the state of that pin by making the output ground for 0, or floating (input) for 1 (via the pull-up).
You stated that the output prop is "showing programmatically" that the output is changing. Did you verify this on the actual output pin?
What value resistor did you use for the pulldown?
Walter
Did you get your problem solved?
Jim
Thanks for everyone’s attempt to help, I won’t be able to revisit this until I fix the code again. At least this time I had a relatively recent backup file to use.
Its regimented, but has saved my bacon many times in the last 40+ years!
Here is a sample...
I'm thinking that Chip must do something similar. I can't imagine keeping a project like the P2v organized.
The way he adds, subtracts, rips apart, glues together, changes names, and supports all of the different platforms is amazing to watch.
When I develop software or other stuff like schematics, layouts, even documents, I check it into the CVS. For example when writing some larger software I check it in when something is working, even only partially. CVS takes care of the numbering that Cluso is talking about. Each Check-in gets a comment.
If making changes which lead to non-working version I can always go back and check out older version. When I leave my desk in the evening I usually check in everything, that gives me some king of backup.
If a version gets released it will be tagged and I can go on with modifications and tests. I can always check out the tagged version.
I never will work without such a safety net.
Having started that about 40 years ago (with RCS on OS/2) I cannot imagine working without that.
The newer revision control systems (GIT, Mercurial, etc) are often more complex in handling and setup and do not allow me that freedom. All checked in repositories are simple ASCII text. If any thng goes wrong I can manually repair it.
And there are tools that show me what has been changed from version 1.2 to 3.4.2.1. This sometimes helps you to find what you have messed up.
I developed my own regime long before PCs or Apple's were thought of, even before the microchip. It has saved my bacon so many times, there is no need for me to relinquish control to another system.
wherever you want to organize multiple versions of documents. Yes, there's a lot of functionality to
support collaborative working that naturally fits with a cloud-based server, but you aren't compelled to
do that for your own projects.
Anyway, I was able to recreate most of the code changes last night from memory and got the software to work again. I was then able to implement the prop to prop link and now it appears to be working. I don't know what is different this time, same commands are being used but the master prop is reading the other prop pin output. I went back to a direct connection between the two prop pins.