I/O board for HA, for 10 digital inputs & 1-wire temp. sensors. What to choose?

Hardware
1

Hi all,

I am planning to hardwire a number of sensor inputs to the HA platform on a RPi.
Outputs will be Zigbee controlled devices.

For the inputs I would like some suggestions from the forum community what kind of I/O board I can use and easily integrate with the HA platform.

I have hardwired 10 inputs coming from an existing alarm system. These inputs are normale closed and carrying 5 or 12 DC (I can select).
These 10 digital inputs I want to connect to a suitable I/O board so I can read the statusses of those alarm signals with HA.

Next to that I also have 5 temp sensors (DS18B20) on a 1-wire link. This 1-wire I also want to connect to HA to record and log the temp readings of those 5 sensors. Can I directly connect the 1-wire to the RPi or do I need also a specific I/O board for this?

Or could I combine the above (the 10 digital inputs & the 1-wire) on one I/O board for HA? Any advice make&model I/O board I could buy for connecting this to the RPi?

2

Would something like this be the solution? How do I get such board communicating with HA?

3

GPIO inputs to home assistant have an issue where they miss state transitions. This might be fixed in the next release. Before you go dropping any money on parts you might want to test this (preferably on more than one GPIO input at a time).

This was my solution to unreliable GPIO inputs: Custom Raspi GPIO Interfcae PCB Project

1 Like
4

Hi Tom,

Thanks for your reply and the warning. I’ll keep that in mind.

Btw, I could also remove the voltage on the 10 wires I have from the alarm system. Those 10 signals are from simpel door/window switches (NC). Could I then wire up those 10 switches directly to 10 of the RPi’s GPIO pins?

Could I also connect then the 1-wire directly to 1 of the other GPIO pins to read out the 5 temp sensors?

5

Yes, all you have to do is enable the GPIO pull-up resistors in your binary sensor config then your voltage free contacts can short the GPIO to ground (switch closed) or let the pull-up resistors pull the input high (switch open).

That would depend on the type of 1 wire sensors you have. 1-Wire - Home Assistant

6

Many thanks.
I have 5x the DS18B20 on 1 wire. As it looks, this should work out of the box, correct?

7

There are relays we (old school alarm guys) have used for registering short presses. I am sure you could use something like that for a sensor? The problem is a computer-based system just can’t register those blips.

8

The pi has interrupts. It is capable of detecting very short pulses, comparable to its clock period (1/1GHz). We’re talking about detecting 10s of milliseconds here. Many many orders of magnitude larger than the clock period.

Also if I remember correctly it had no trouble detecting the on transition, it just used to miss transitions back to off, even on seconds or more long pulses.

9

You say “used to” has this been corrected in some way?

10

“Used to” as in when I was using it, many moons ago. I have been keeping an eye on the issue, some progress in identifying the issue but it is still open. So I assume the problem is still present.

11

Ah got it! Thanks for clarifying. You are using your custom made board now right? I made some comments / observations on that thread. I am interested in building a couple for testing… Maybe a group buy is in order?

12

I’ve already replied :wink: