Posts made by Nate
Omega and Cellular... any hope?
So I've been working on making a project that needs to utilize the USB GPS and a cellular data connection. I got my Hologram SIMs (although I think Ting would be cheaper) and went to order the cellular expansion and... nope. Apparently they were only for sale on Kickstarter. Looking in the forum I also found someone talking about not being able to use the cellular expansion and the USB GPS both due to some sort of restriction of only one device allowed to be created on the Omega.
So is there any hope? Any alternative cellular card I could use along with the USB GPS dongle? I tried asking support but have only gotten back silence.
Any help would be appreciated.
Question about LiPo batteries and charging.
I just bought a 10,000mAh 3.7v LiPo battery. It is my first battery and I don't know much about them. But I have some questions / concerns.
When charging (and probably discharging) the board gets really hot. To the point where if you touch it, you can only hold your skin against it for a few moments.
If the board is plugged into micro-usb for power and I plug in or out the battery, the board restarts. And if the board is plugged into the battery and I unplug in the micro usb the board turns off. This is the opposite of what they show in the getting started guide.
While charging, I'm watching the output of power-dock2 as well as running this python script every 10s. But their output is way off from each other.
# power-dock2 -p Battery Voltage Level: 3.92v Battery Level Percent: 92%
# python Writing 'Battery(V): 3.87 V' to display Writing 'Battery(%): 52%' to display
I also was running power-dock2 every 10s into a file and see some jumps in there as well which I don't understand:
Battery Voltage Level: 3.72 V Battery Level Percent: 88 % Battery Voltage Level: 3.72 V Battery Level Percent: 88 % Battery Voltage Level: 3.73 V Battery Level Percent: 95 % <--- much higher Battery Voltage Level: 3.73 V Battery Level Percent: 88 % Battery Voltage Level: 3.72 V Battery Level Percent: 88 %
So I'm not sure if this battery is safe, or if all of this including the heat is normal, if the heat could damage the board, etc. If this isn't normal I'll return the battery.
RE: Writing python scripts for the RFID/NFC expansion
I'm just starting with the expansion and also finding it frustrating to use. But I had some comments on your thread and thought I'd share what I've figured out in the two days I've been messing with it.
I'm a security researcher and need to build a handheld, barry powered device to scan a client's employees badges to do an audit.
Me too! Specifically I do penetration testing of all sorts. I would think you'd want something with a bit more range for an engagement?
basically what i'm asking is how to control the rfid/nfc exp from inside a progra...any program: python node.js, etc.
First, you should forget there are any "tools" installed on the Omega for use with the expansion. And while the documentation is frustrating, it does tell us some useful information that would have taken us a few minutes to figure out or if you are me quite a few minutes to figure out:
The Expansion is based on the popular PN532 NFC Chip and communicates with the Omega via UART1.
- PN532 chip
- talks via UART1
# nfc-scan-device nfc-scan-device uses libnfc reboot-3483-gd1bcad0 1 NFC device(s) found: - pn532_uart:/dev/ttyS1: pn532_uart:/dev/ttyS1
- device is on /dev/ttyS1
error libnfc.driver.pn532_uart Serial port already claimed: /dev/ttyS1 nfc-mfultralight: ERROR: Error opening NFC device
- their "tools" are using the libnfc driver
Ok so to get back answering your question, to control the expansion from inside a program you have two choices:
- Find a library in the language of your choice that uses the libnfc driver and tell it to talk to a pn532 chip on /dev/ttyS1.
- Find a library in the language of your choice that can talk to the pn532 on /dev/ttyS1 directly.
OK, I figured it out. Here's a test script I wrote real quick to have a proof of concept:
import os scan = os.system("nfc-list") def scanFunc(): while 1: scan return scan print(scanFunc()) import string outfile = open("result.txt", "w") outfile.write(scan)
Even ignoring the issues with the code I probably wouldn't want to use this in any real-world scenario. Did you by chance come up with something else? And honestly for something like what you are trying to do here you could just write a shell script and save yourself the overhead of the python interpreter.
However, if you do want to write something in python, find a library that lets you use one of the above two methods I mentioned and I think you'll be much happier with the expansion. I know I was.