• 10 dec 2017: forum version update. In case of issues use this topic.
  • 30 nov 2017: pilight moved servers. In case of issues use this topic.
Hello There, Guest! Login Register


Bandpass filter problem
#11
(01-06-2018, 10:13 PM)curlymo Wrote: The 1 minute is what it should be. Can you try the receiver without filter to make sure the receiver isn't the fault?

I usually have the receiver connected without the filter. It works but it creates many false positives.

In one of my posts above you can see that it even works with the filter, since I received one oregon protocol message. But somehow after a while it does not work anymore and only shows the firmware messages. When I do not use it for quite some time it works again.


Maybe it has to do with the development board my ATTiny85 is connected to? I was not able to connect it to a breadboard since its pins are too short. Some capacitor could interfere and it only works when the capacitor is discharged? You can probably guess that I am not an expert on these things Blush Here is an image of my setup attached as a link:

https://ibb.co/nwyTsG
 
Reply
#12
It would be a good idea to start using the supported sender/receiver kit for pilight to rule that out.
 
Reply
#13
You do need to follow some basic design rules for digital circuits.
The first one is to have a proper ground grid, in particular it should be a star configuration and common ground for all ground wires at the 4.7uF capacitor of the power supply source for your external circuits.
The second one a proper power supply output starting with a 4.7uF tantalum capacitor and a 100pF ceramic capacitor plus another 100pF capacitor at each device (wires of the 100pF as short as possible).
You are using the 5V power supply of your Pi. Be cautious as you do need to limit current on the gpio lines as the voltage levels used are 3.3V and you do need to limit the current flow.
What is your planned voltage level for logical
low and high condition ? (For the output of your receiver circuit and the input of your filter, AND output of your filter and input of your raspberry, what is the current load of the output, what is the current load input requirement ?, do you need pull up resistors ? Do you need to convert the voltage level of the output drivers ?
There is a recommended design layout in the wiki, do you use it ?
As you can receive the filter protocol I assume that the problem is between the LPF input and the RF receiver output.
Once you have the basics working, why do you worry about false readings of pilight-receive ? The GUI for example is only passing validated received data to the user, removing all false readings.



Gesendet von iPhone mit Tapatalk
 
Reply
#14
(01-07-2018, 10:26 AM)wo_rasp Wrote: You do need to follow some basic design rules for digital circuits.
The first one is to have a proper ground grid, in particular it should be a star configuration and common ground for all ground wires at the 4.7uF capacitor of the power supply source for your external circuits.
The second one a proper power supply output starting with a 4.7uF tantalum capacitor and a 100pF ceramic capacitor plus another 100pF capacitor at each device (wires of the 100pF as short as possible).
You are using the 5V power supply of your Pi. Be cautious as you do need to limit current on the gpio lines as the voltage levels used are 3.3V and you do need to limit the current flow.
What is your planned voltage level for logical
low and high condition ? (For the  output of your receiver circuit and the input of your filter, AND output of your filter and input of your raspberry, what is the current load of the output, what is the current load input requirement ?, do you need pull up resistors ? Do you need to convert the voltage level of the output drivers ?
There is a recommended design layout in the wiki, do you use it ?
As you can receive the filter protocol I assume that the problem is between the LPF input and the RF receiver output.
Once you have the basics working, why do you worry about false readings of pilight-receive ? The GUI for example is only passing validated received data to the user, removing all false readings.



Gesendet von iPhone mit Tapatalk

Wow, thanks so much wo_rasp. I guess I did a lot wrong. I will now have to research much more. Your post seems like a good start, pushing me in the right direction. If I ever hit a wall, I will post here again.
 
Reply
  


Possibly Related Threads...
Thread Author Replies Views Last Post
Question Passive Component Band-pass filter ripper121 8 1,292 12-16-2017, 01:38 AM
Last Post: wo_rasp
  Filter kit in 315 receiver? ceandre 1 1,035 04-14-2017, 10:10 PM
Last Post: wo_rasp
  Low Pass Filter and Receiver in Series? re-post Gustavo Woltmann 1 1,163 03-08-2017, 05:25 PM
Last Post: pilino1234
  Filter settings in config.json Saiyato 100 22,409 02-22-2017, 08:24 AM
Last Post: wo_rasp
Rainbow Lowpass filter - how DOES it work? DE8MSH 6 2,632 10-07-2016, 09:25 PM
Last Post: wo_rasp
  Low Pass Filter and Receiver in Series? Hauke 3 2,312 08-30-2016, 08:25 AM
Last Post: wo_rasp
  New filter version curlymo 0 1,211 04-02-2016, 08:05 AM
Last Post: curlymo
  Band-pass filter parts curlymo 60 56,305 01-08-2016, 12:23 AM
Last Post: gneandr
  low pass filter francois.leprieur 3 1,868 12-20-2015, 10:18 AM
Last Post: curlymo
  Low-pass Filter wiring hazzard 4 2,701 11-15-2015, 08:35 AM
Last Post: woutput

Forum Jump:


Browsing: 1 Guest(s)