Hacks Archive

More 434MHz stuff to look at later

Posted August 20, 2016 By Landis V

Acurite #0899 self emptying rain gauge – at Amazon

Blog post on reversing the signal from Acurite temperature sensors; may be similar for the rain gauges.  Also mentions the RTL SDR.  Probably wouldn’t be bad to have.

Another blog post regarding reading the Acurite 5n1 station.  Possible that part of this will already cover the rain gauge.  Also discusses SDR and mentions the rtl_433 tool.

This blog post looks like rtl_433 supports the Acurite 896 decode natively, so if the protocol is similar or the same it may be simple.

RTL Software Defined Radio – at Amazon – seems like it’s probably a decent model, some good reviews.  Looks like there’s a little more to it than just “buy this and set up the software”.

Bought a cheap receiver off of eBay from Hong Kong for $7.31 (original listing).

Also, here was an Instructable about making a cheap combination RF/Bluetooth/433 MHz remote using an Arduino.

Additional Links

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On Networks N150R Routers

Posted June 13, 2016 By Landis V

Picked up a couple of these from Newegg for free plus a couple of bucks shipping after rebate.  Figured that in combination with a couple of relays on the GPIOs, I could probably use them for switches or work with the serial port for a sensor connection.  Just a few notes on them.

OpenWRT 15.05 Chaos Calmer patched to expose the GPIOs:  https://micu.webserwer.pl/pmwiki/pmwiki.php?n=OpenWRT.Downloads

Forum thread on not flashing direct to 15.05.1; I went to 14.07, then to 15.05.  https://forum.openwrt.org/viewtopic.php?id=51576

OpenWRT Wiki page with device info including GPIOs https://wiki.openwrt.org/toh/netgear/wnr612v2

Controlling the GPIOs

From here, the simple way to control the GPIOs natively is with the “brightness” value for the LEDs.  By example for the LAN1 LED (others are in the same path):

root@OpenWrt:~# echo 0 > /sys/class/leds/netgear\:green\:lan1/brightness
root@OpenWrt:~# echo 1 > /sys/class/leds/netgear\:green\:lan1/brightness

Update 9/18/2016

Finally got the LAN2 LED peeled off of the board, had a heck of a time with it.  After doing so, I discovered that I only get ~2.5v across the pins when the GPIO is active… not enough to drive my 3.3v relays.  I assume they are probably using a voltage divider here.  Measuring the resistance between the positive and negative ends of the LED without power applied, I get about 1580 ohms one direction, and 670 in the other.  There appears to be a ~960 ohm resistor at CA111, but I haven’t figured out exactly how this ties in.

Update 10/9/2016

Spent some time with this again over the past couple of days.  I removed the resistor at CA111, but apparently it is not a divider.  May need to spend some time to see if I can make something work with a 2N7000 MOSFET or something like that, but I’m pretty novice so that will take some effort.

I did test out my 433MHz ASK receiver on the TTL serial port, but without much luck.  This OpenWRT page was helpful in getting stty installed and setting the baud rate on the serial port,

‘stty -F /dev/ttyS0 9600 clocal cread cs8 -cstopb -parenb’ to set the config, and
‘stty -F /dev/ttyS0 -a’ to verify the config

but still didn’t get any output.  I’ll have to give it a shot with my Raspberry Pi just to see if I can get anything out of there.

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Purpose

I recently purchased an Ivation barbecue thermometer which is supposed to be a pretty decent similar build to the Maverick 733 (I believe).  Of course, one of the first things that comes to mind is how to tie this in to some type of IP connected system so I don’t have to rely upon the included receiver and its limited range, and can instead take advantage of wifi, Internet, and the smartphone I always have with me.  Turns out it should be pretty feasible in conjunction with the Raspberry Pi I already have plans to set up as a sort of garage controller.  That device will be connected by ethernet and will have a constant and reasonably close proximity to my smoker and grills already.  This post is for my notes on links that will be useful when (if?) I actually get around to making this work.

Software/code links and notes will come later, after I actually get the equipment to start testing.

About the BBQ thermometers

The Maverick (and presumably Ivation) transmit on the 433.92MHz frequency using OOK.  The Hackaday link to Bob Blake’s article below describes the communications protocols and encoding.

Links

Update 10/9/16

Spent some time trying to get this working with my On Networks N150R over the past couple of days without much luck.  May have to give it a try with one of my Raspberry Pi’s and see if I can get it working there, if for no other reason than to verify that the receiver module I purchased is functional and/or that I have it wired somewhat properly.

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Pogo Mobiles, SiliconDust HDHomeRun, and cabling

Posted January 10, 2015 By Landis V

Last night I finally got around to doing a little bit with the Pogo Mobile units I had installed Debian on.  Not much so far, just got dnsmasq loaded on the unit that will become my DHCP and DNS server (replacing the same functionality on my router, so the next time I swap out a router I don’t have to worry about transferring internal DNS or DHCP reservations).

Haven’t done much of anything with the unit that I will be configuring as a CA, but did run across a couple of good reads on how to do a CA “right”.  The OCSP article fills in a piece I’d like to have if I’m going to go to the trouble of setting up my own CA “for real”.

I stopped at Charter yesterday and exchanged one of my digital cable tuners for a CableCard, so I am anxious to get my HDHomeRun set up and start playing with it.  I don’t like the way my CATV cable is organized, and it’s also older RG-59.  Having purchased some RG6, I’m now in the process of centralizing that system, pulling new cable to at least a couple of locations, and will probably use the opportunity to put an ethernet drop in my garage as well.

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U-Boot w/ MMC/SD-card booting for Pogoplug Series 4

Posted December 3, 2014 By Landis V

http://forum.doozan.com/read.php?3,7477,10982

Just bought one of the mobile units today.  This thread appears to have some instructions on getting Debian set up on the SD.  Will have to come back to it when the unit arrives and I have a couple of minutes.  Thinking this could make a great router/firewall.

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NetBoy’s Camper Page

Posted September 25, 2014 By Landis V

http://home.comcast.net/~netboy/

Some very useful mods for the new camper.

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How to Root US Cellular Galaxy S4 SCH-R970

Posted February 8, 2014 By Landis V

http://www.droidviews.com/how-to-root-u-s-cellular-galaxy-s4-sch-r970/

Nice, functional root page for the US Cellular (USCC) Samsung Galaxy S4 SCH-R970.  Haven’t checked into it much to see what flags it sets, but the instructions seem to work well, and ChainFire has been around long enough I consider them fairly reputable.

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