Sometimes you can find a good deal on used power supply from various vendors. In my case it was Cisco C3K-PWR-750WAC and RPS 2300. The problem is, that they don’t output any voltage until they are plugged into device. The question is, how to fool them into thinking they are plugged in. Update: including N2200-PAC-400W

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I recently came across a Wowme U300Q car camera on an auction at aukro.cz . At first glance, it seemed like a promising piece of tech, but after trying to use it, I quickly realized there was a major flaw—it didn’t rotate recorded files and it was not just an issue with my piece, also reviews confirmed it as a global problem. For anyone familiar with dash cams, this is a critical issue because, without rotating files, the camera quickly runs out of storage and stops recording.

Continue reading Hacking Wowme U300Q Car Camera to Actually Work

I always search for this so I will write it down here.

Client

cd /etc/wireguard
wg genkey | tee privatekey | wg pubkey > publickey
vi wg0.conf
[Interface]
PrivateKey = 
Address = 10.9.0.X/24

[Peer]
PublicKey = dg1cKCId81d6h5cWUQ61BMHksBbi0FdFnitjxDuOuno=
Endpoint = vpn.danman.eu:51820
AllowedIPs = 10.9.0.0/24
PersistentKeepalive = 25
wg-quick up /etc/wireguard/wg0.conf
systemctl enable wg-quick@wg0.service
systemctl edit wg-quick@wg0.service
[Service]
Restart=on-failure
RestartSec=5s

Server

systemctl stop wg-quick@wg0.service
vi /etc/wireguard/wg0
systemctl start wg-quick@wg0.service

Reload

wg syncconf wg0 <(wg-quick strip wg0)

TL;DR: the problem is usually in corrupted data in SPI NAND flash, you need to download the original config data and flash back working modem firmware.

I noticed there is quite a lot of offers with used not working 4G router TL-MR100 in aukro.cz . I bought one with hope I can easily fix and use it. But the fix turned out to be not that easy.

Continue reading Fixing broken TP-Link TL-MR100

Recently, I was looking for an affordable LoRaWAN gateway with 3G/LTE connectivity. I like Mikrotik products because they are easy to use and have many features (e.g. Wireguard VPN 😎 ) . I found RBwAPR-2nD which has a miniPCI-e slot which can be fitted with R11e-LR8 LoRaWAN gateway module or a card for mobile network connectivity (e.g. R11e-4G). The problem is you cannot have both because there is only one slot. Or can you?

Continue reading miniPCI-e dual USB card extender

It is a very simple device for about $15. The main SoC is GX6605S. There is some limited info about this chip on C-SKY page and some technical docs at their tools repo. It communicates with a Bluetooth module TLSR8266 using UART. There is also 4MB SPI flash holding the whole bootloader called GxLoader, Linux kernel and filesystem with the main app. The last important chip is RDA5815M which handles the RF to I/Q conversion. In the future I plan to add an USB-to-Ethernet adapter and repurpose it as an cheap opensource SAT>IP server.

Continue reading Hellobox B1 satellite finder teardown