2021 Aug 19, 09:29 AM
(This post was last modified: 2021 Aug 19, 07:49 PM by astrogerard.
Edit Reason: added picture of plugin
)
Hi Dan,
Good to see you get it working too.
My plugin in a basic version works. I can configure multiple boards based on the number of boards defined in nbrd:
For now my plugin is based on the pcf8574 wich has 8 channels but I've seen also boards based on the pcf8575 which has 16 channels. I'm changing my design a little bit to support the pcf8785 as well.
I'm a bit new to web.py and am (steep) learning the interaction between the (template) html and the code. Therefore it will take some time to "present" a beta version of my plugin. The good news however is that it already works :-)
Also I'm investigating the power requirements when connecting the maximum number of boards in relation to connecting to the Pi. Potential issues are connecting to 5v or 3.3v. 5v from the Pi can easilly drive all 64 (or 128) optocouplers but has a potential issue when connecting sda and scl from a 5v device to the 3.3v Pi. Safer is to connect to 3.3v but the Pi will struggle with powering all the optocouplers. I'm now thinking of a safe solution somwhere in between. A hardware prototype is on my bench now connected to the scope so some measurements should give the right answers.
So, a lot is done and has to be done. I will continue with both the plugin and hardware and will give updates here. I might need some assistance with web.py and the interaction between the html template but I will give a "shout out" when needed.
--Gerard
Good to see you get it working too.
My plugin in a basic version works. I can configure multiple boards based on the number of boards defined in nbrd:
For now my plugin is based on the pcf8574 wich has 8 channels but I've seen also boards based on the pcf8575 which has 16 channels. I'm changing my design a little bit to support the pcf8785 as well.
I'm a bit new to web.py and am (steep) learning the interaction between the (template) html and the code. Therefore it will take some time to "present" a beta version of my plugin. The good news however is that it already works :-)
Also I'm investigating the power requirements when connecting the maximum number of boards in relation to connecting to the Pi. Potential issues are connecting to 5v or 3.3v. 5v from the Pi can easilly drive all 64 (or 128) optocouplers but has a potential issue when connecting sda and scl from a 5v device to the 3.3v Pi. Safer is to connect to 3.3v but the Pi will struggle with powering all the optocouplers. I'm now thinking of a safe solution somwhere in between. A hardware prototype is on my bench now connected to the scope so some measurements should give the right answers.
So, a lot is done and has to be done. I will continue with both the plugin and hardware and will give updates here. I might need some assistance with web.py and the interaction between the html template but I will give a "shout out" when needed.
--Gerard