cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Android tablet for pin access

Tue Jul 15, 2014 3:00 am

Hi all,

I'm trying to see how I can go about interfacing a robust soft keypad to the Raspberry Pi for pin access. I'm open to suggestions, but thought a $125 Android tablet would be a robust choice.

I will be using the RPi as a master and Arduino as a slave. I am using an RFID scanner connected to the Arduino and the Pi will be communicating with it via serial. I'm looking to see how I can go about getting the tablet to accept input from the tablet (via PhP, etc) to the Pi so it can relay the message to the Arduino.

Suggestions, comments are welcomed. Thank you in advance!

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FLYFISH TECHNOLOGIES
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Re: Android tablet for pin access

Tue Jul 15, 2014 3:37 am

Hi,
cisco_kid wrote:Suggestions, comments are welcomed.
[joke mode on]Your message reminds me to a local leader of a political party - he talks something, you don't know what and why, but you feel that he doesn't know much about the subject and is afraid this to be found out. The worst thing is that he expects you to solve these undefined issues...[joke mode off]


Best wishes, Ivan Zilic.
Running out of GPIO pins and/or need to read analog values?
Solution: http://www.flyfish-tech.com/FF32

riklaunim
Posts: 265
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Re: Android tablet for pin access

Tue Jul 15, 2014 6:04 am

Tablet can SSH into RPi, or use another serial connection via USB or Bluetooth UART. Then you would get the terminal on RPi. Some VNC application would allow getting desktop on RPi.

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Cancelor
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Location: UK

Re: Android tablet for pin access

Tue Jul 15, 2014 7:33 am

It isn't too clear what you have in mind but have you looked at WebIOPI?
Can't find the thread you want? Try googling : YourSearchHere site:raspberrypi.org

cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 4:27 pm

FLYFISH TECHNOLOGIES wrote:Hi,
cisco_kid wrote:Suggestions, comments are welcomed.
[joke mode on]Your message reminds me to a local leader of a political party - he talks something, you don't know what and why, but you feel that he doesn't know much about the subject and is afraid this to be found out. The worst thing is that he expects you to solve these undefined issues...[joke mode off]


Best wishes, Ivan Zilic.
[joke mode on]Thank you for the helpful post, I'm hope your business also benefits from your jokes as well[joke mode off]

cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 4:30 pm

riklaunim wrote:Tablet can SSH into RPi, or use another serial connection via USB or Bluetooth UART. Then you would get the terminal on RPi. Some VNC application would allow getting desktop on RPi.
This is an option, thanks. I thought about this and wanted to be sure when someone looks at the tablet they don't know it's a remote desktop to another PC. Are there any reliable LCD screens that can do the same job? I heard some need to be calibrated before you use it.

cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 4:34 pm

Cancelor wrote:It isn't too clear what you have in mind but have you looked at WebIOPI?
I came across WEBIOPI awhile ago, but can it be integrated with RFID door tags?

Basically instead of a physical hard keypad to punch in a PIN number, I would like to use a touchscreen keypad that will interact with the Pi for authentication.

scotty101
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Re: Android tablet for pin access

Tue Jul 15, 2014 4:39 pm

Have you considered using the Adafruit PiTFT rather than the tablet?

It would be quite simple to create an application that could accept a pin from the user to allow access.
Electronic and Computer Engineer
Pi Interests: Home Automation, IOT, Python and Tkinter

riklaunim
Posts: 265
Joined: Tue Apr 22, 2014 7:34 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 4:40 pm

Basic RFID readers emulate keyboards. If you keep focus on a form field reading the tag will print its ID into that field and submit the form. Backend web application can then check if the code is valid and can be granted access :)

cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 6:35 pm

riklaunim wrote:Basic RFID readers emulate keyboards. If you keep focus on a form field reading the tag will print its ID into that field and submit the form. Backend web application can then check if the code is valid and can be granted access :)
Thanks riklaunim, I had already purchased the Adafruit PN532 NFC/RFID breakout board and it doesn't display like a keyboard. It displays similar to this:

Code: Select all

ISO/IEC 1xxxxA (106 kbps) target:
    ATQA (SENS_RES): 00  xx  
       UID (NFCID1): xx  fb  xx  d0  
      SAK (SEL_RES): xx  
I think it will display differently on the Arduino, I have yet to test it.

cisco_kid
Posts: 11
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Re: Android tablet for pin access

Tue Jul 15, 2014 6:37 pm

scotty101 wrote:Have you considered using the Adafruit PiTFT rather than the tablet?

It would be quite simple to create an application that could accept a pin from the user to allow access.
Thanks for the suggestion, however I'm looking for something a little bigger, perhaps a 7 inch screen.

riklaunim
Posts: 265
Joined: Tue Apr 22, 2014 7:34 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 8:35 pm

I see serial RX/TX on it. If it has all the features you need you can handle it even with the tablet using USB or Bluetooth UART adapter if you want to write an Android app... if on Raspberry then you can VNC the desktop to laptop or use something like Atrix Lapdock (HDMI screen, touchpad, keyboard). Simple desktop app can handle the RFID/NFC via serial and do other actions if needed.

cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 10:51 pm

riklaunim wrote:I see serial RX/TX on it. If it has all the features you need you can handle it even with the tablet using USB or Bluetooth UART adapter if you want to write an Android app... if on Raspberry then you can VNC the desktop to laptop or use something like Atrix Lapdock (HDMI screen, touchpad, keyboard). Simple desktop app can handle the RFID/NFC via serial and do other actions if needed.
ruklaunim, thanks for the idea. I'm not too savvy with Android, but your suggestion is possible. Will this mean I can eliminate the Raspberry Pi all together? (pin app on Android interacting with the Arduino)

Do you or know anyone who has examples of interacting Android with the Arduino? Is there some type of test harness that can be plugged into the Android to expose the RX/TX and test with?

riklaunim
Posts: 265
Joined: Tue Apr 22, 2014 7:34 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 11:10 pm

There are even books about Android + Arduino. In your case you don't need Arduino if that RFID/NFC reader is the only device you want to plug in. USB/Bluetooth UART dongle is all you need (for serial communication).

hm......... if you use NFC enabled phone or tablet then you won't need that RFID/NFC reader as the phone will be able to read NFC tags - so only software would have to be written (read, check if the string is valid, do action etc.).

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FLYFISH TECHNOLOGIES
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Re: Android tablet for pin access

Tue Jul 15, 2014 11:22 pm

Hi,
cisco_kid wrote:Do you or know anyone who has examples of interacting Android with the Arduino?
If you'd go with UART-over-bluetooth, you need a bluetooth interface with SPP profile (eg. HC-05 or HC-06 module) on Arduino side and an Android communication app handling bluetooth.

There is one company whose business is based on jokes, and on its web page you can download Eclipse project for the Android app, dealing with bluetooth communication. Although, the mentioned application will not work with this your bluetooth link without various modifications, you get suitable project framework for your app. Additionally, you might also get some ides while analyzing this source code.


Best wishes, Ivan Zilic.
Last edited by FLYFISH TECHNOLOGIES on Tue Jul 15, 2014 11:25 pm, edited 1 time in total.
Running out of GPIO pins and/or need to read analog values?
Solution: http://www.flyfish-tech.com/FF32

cisco_kid
Posts: 11
Joined: Mon Jun 02, 2014 3:37 pm

Re: Android tablet for pin access

Tue Jul 15, 2014 11:23 pm

riklaunim wrote:There are even books about Android + Arduino. In your case you don't need Arduino if that RFID/NFC reader is the only device you want to plug in. USB/Bluetooth UART dongle is all you need (for serial communication).

hm......... if you use NFC enabled phone or tablet then you won't need that RFID/NFC reader as the phone will be able to read NFC tags - so only software would have to be written (read, check if the string is valid, do action etc.).
The wheels are now turning. I will still need Arduino because I intend to use a door strike with the system, so it will act like a micro controller for door release, etc. I didn't think of NFC with the Android Tablet either. In your suggestion, I wouldn't really need the Pi. I intend to use the Pi later for a central database, but it seems it's not necessary for the system to work independently. Now...to develop an app. Any suggestions for a newbie such as myself?

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