I button

jayel

Hello,

I was wonderling if can connect an 1 wire I button to the unipiboard?
https://www.maximintegrated.com/en/products/comms/ibutton.html

John

jayel

Hello,

I was wonderling if can connect an 1 wire I button to the unipiboard?
https://www.maximintegrated.com/en/products/comms/ibutton.html

John

Freud-Schiller

Hi John, I have the same task. i Button ist connect, but evok does not see it. Can i find it under the dev tree? Best Regards, FS

Support for iButtons are not implemented yet.

Freud-Schiller

Hello Tomáš,

is this topic on the todo list early or a little bit later?

Can I access the iButton in Linux itself? A simple script could do the job for me. So if a iButton is detected by the script I could run something like "wget -qO- http://your.pi.ip.address/rest/relay/3 --post-data='value=1'".

Can I access the iButton in the Linux file system?

Best regards,

F-S

I would like to help you but unfortunately I do not have any iButton device to test with….

Freud-Schiller

Hello Tomáš,

can I send you some Buttons? That would be no problem at all

It´s really only a question where the iButton can be seen in linux.

Best regards,David

Freud-Schiller

Ok, I have more information:
The devices apear at:

/sys/bus/w1/devices/

BUT there has to be a 1wire master. Is the UNI PI the master?

And evok DOES show me the temp sensor be default. How is this done?

You can try a simple python script. If the Ibutton will be accessible with python-ow, It wont be difficult to implement a driver for the iButton in evok.

try something like this and stop evok befor that:

import ow
ow.init('--i2c=/dev/i2c-1:ALL') #not sure about this
print ow.Sensor("/").sensorList()

If it will print the sensor, try something like

sens = ow.Sensor("/ibutton_address")
print sens.temperature #might be different depending on your sensor

Freud-Schiller

Did a lot of thinking

lets sort the things out:

1. the ibutton has ONLY 2 wires. DQ and GND. Do I have to use a bypass like in the howto ?

http://www.behindthesciences.com/electronics/raspberrypiibuttonsystem

Or can i simply connect DQ und GND to the uni pi?

2. the 1wire subsystem is connected through the i2c bus, right?

My problem is, that I do not know where the 1wire sensors appear in the linux device tree in the set up.
If I could read them at the shell, I could switch a relay on the uni pi on and off. That would be fine.

3. Last point

I01/GPIO04 /Digital Input is used be the majority of howtos to connect a 1wire button. e.g.

http://www.behindthesciences.com/electronics/raspberrypiibuttonsystem

It would be a really dirty solution, but would it be possible the disconnect the GPIO 04, lossing the input 1 and to the connection like in the howto? Would the software part (e.g. owfs) interfere with the evok api?

Freud-Schiller

Hello Tomáš,

can you help out?

Best regards,

F-S

Hello,

sorry for the late reply - really busy here.

1. Yes it is OK to connect the DQ and GND to the DG and GND of the 1Wire port RJ45 - see wiki for pinout.
2 + 3. You can install the owfs configure it to use the i2c master and comment out the ow bus in evok.conf so you will have all the 1wire sensor acessible by the sysfs. And of course you can even make a custom cable for the GPIO4, butl also comment out the pin in evok.conf.

Have you tried the steps in my previous post? Any result?

Freud-Schiller

Hello Tomáš,

I was busy also, so sorry for the late reply.

1. the pinout is fine. Do I have to connect 3,3V via a resistor to the DQ or just connect it to the DG?
2. this would be very good for me. so if I install owfs, disable the ow support in evok.conf I would see all the ow devices in the Linux tree, right?
so step 3. is not needed, right?

I tried the steps in your previous post, but no results

Best regards, F-S

Hello,

1. Just connect DQ to DQ directly
2. Right