In my flat they have installed these new digital door phones running on two wires manufactured by Tesla:
I wanted to be notified when someone rings when we are not at home so I decided to reverse engineer it.
Continue reading Reverse engineering Tesla 2-bus protocolI have RNS315 radio/navigation/media system (I will call it unit) in my car. I bought it with maps from 2014 which are hugely outdated so I started to research how to update the maps.
As I am dealing with flashing SPI NANDs in WSON-8 package, I wanted to make my life easier by using a socket. You can buy one for about $6 on ali but I also wanted to try a different approach with pogo pins.
Continue reading DIY WSON-8 socketTL;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-MR100Recently, 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 extenderIt 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 teardownSeed Studio offered me a sample device (see specs) for exchange for an article on my blog and I accepted. The device came a few weeks ago so I am fulfilling my part.
When it came, I went to their page and searched for some example code to test and I picked GitHub Stats example. The documentation is pretty good but it describes the usage with original Arduino IDE which is not my weapon of choice. Some time ago I noticed PlatformIO added support for this device so I wanted to use it.
Continue reading Wio Terminal in PlatformIORecently I saw an interesting video about chip decapping using only hot air.
It looked quite easy so I gave it a try and indeed I managed to extract three dies without breaking them or any other problems so it was 100% successful on first try.
You can see die pictures below. From left to right: GD32F103C8T6 main die, it’s flash and MAX7219
I was thinking how to automatically generate PDF schematics for my public KiCad repos without committing it to the repo itself. I managed to make Travis CI do this for me and put the output to Github Releases.
If you are interested, read on.
Continue reading Using Travis CI for KiCad PDF schematic generationI wanted to do some laser cutting so I thought I will just order a laser and mount it to my 3D printer. I ordered one with most orders on ali: https://www.aliexpress.com/item/32562052620.html . When it came, the fun started.
Continue reading Ender 3 as a laser cutter
