Sometimes you need a workaround for SSH to an host. On my case, i cannot SSH to a ppp connected Raspberry Pi, but he can SSH to every other host. Solution is simple: ppp-Pi will SSH to a remote SSH server leaving a door open. Then i can SSH to my host, and login to my Pi. Confused? I know.
[Edit]: Thanks Hackaday for the highlight! Part two of the hack – having a 77 year old learning how to use an Android phone – is ongoing. Proof of success: her instagram account.
After building my DIY 16.5 dBi (probably with pornographic levels of VSWR – hopefully i can get an antenna analyzer on that by the next few weeks) and proofing the concept of a feasible 3G gateway, i had to put everything inside a nice IP65 box and set it up outside. Initially i was aiming at using a modded WR703N with Rooter firmware and a Huawei E3131. After burning both of them, i had to resort to a Raspberry Pi Zero.
Principle of operation: Raspberry Pi handles the PPP session from the USB modem, creates an WiFi network via hostapd and uses iptables for the rest.
Notes on weatherproofing something
water + electronics = bad. Solution?
heat + electronics = bad. Solution?
Sealed box with ventilation.
Sealed box with ventilation + electronics = moisture during low temperature. Solution?
Heat it when it’s cold.
230VAC outside = bad idea. Solution?
Industrial grade 230VAC to 5VDC PSU – i used this one from Mean Well – RS-35-5 (link to manufacturer) placing it within the attic and routing 5m of 2×0.75mm2 cable outside – 6m total, minimum voltage drop.
So, this is not a trivial problem to solve. My solution? IP65 grade box (IP rating table right here) with a breathing hole, DHT22 sensor inside, DS18B20 outside, python measuring things. More details below…
I’ve seen this a few times, and it’s a hack worth to share.
Many times, we found ourselves owning a car with a CD player, but no AUX-IN. Who uses CD’s these days, anyway? Noah decided to un-crapify his car audio on a 2001 Ford Focus.
The hack itself is pretty simple. Open up the unit, and you’ll find two separate modules: CD player, and radio/amplifier unit. Both are connected through a flex cable.
Noah was fortunate, since he had taps for each pin, so he didn’t had to solder directly on the plug’s pins. So, he identified ROUT, LOUT and a ground connection, soldered the pins, and he’s ready to go.
Since he tapped on the CD player’s pins, a CD must be inserted in order to trigger the input.
Easy as recording an audio CD without any tunes in int: plain old silence.
So, i have a OWL CM130 wireless energy monitor for keeping an eye on power consumption at home.
It’s a great little gadget, but also a very cheap one: i bought it a few years ago for around 30€ in eBay, but it won’t let me do anything with the data, other than display it.
These usually work in 433MHz band, and i happen to have a 433MHz AM receiver similar to this one: http://ardumarket.com/en/transmisors/transmisor-rf-fs1000a-330-443mhz-arduino-pic-id19.html