#garfield Logs

Mar 04 2024

07:27 AM polprog: rue_mohr: i asked cause 13.56MHz can be read with smartphones, 125kHz not
07:40 AM polprog: :)
07:40 AM polprog: you can store a URL in a mifare tag and then the phone OS can open it when you put the tag close by
07:40 AM rue_mohr: yea, I got a smartphone app and did one
07:40 AM rue_mohr: there was a free app for writing them
07:40 AM rue_mohr: but I think it was a work phone that I dont have anymore
07:40 AM rue_mohr: had to be...
07:40 AM rue_mohr: this has a serial port, so ...
07:40 AM polprog: the reader?
07:48 AM rue_mohr: yea
07:48 AM rue_mohr: says HW-33 on it
07:52 AM rue_mohr: https://www.aliexpress.com/item/1005003226372958.html
07:52 AM rue_mohr: 13Mhz
07:58 AM rue_mohr: something is super artificial, the election isn't crashing the usd, it always does
08:06 AM polprog: heh, it runs on stm8s003
08:06 AM polprog: thats basically the NXP RFID reader chip and the STM8 to talk over uart
08:06 AM polprog: a lot of chinese stuff uses STM8
08:07 AM polprog: The 433MHz LoRa modules I have also have an STM8 inside
08:09 AM rue_mohr: I'm not sure what it does. do you think it can buffer writes?
08:10 AM polprog: I have no idea
08:10 AM polprog: its there just as a uart to spi converter or something
08:10 AM polprog: probably convers the tag data to ascii
08:10 AM rue_mohr: its not spi
08:10 AM rue_mohr: its ttl serial
08:11 AM rue_mohr: 1)MF RC522 applicable to all kinds based on ISO / IEC 14443A standard and require application of low-cost, small size, high performance and power of a single non-contact communication.
08:11 AM rue_mohr: ""
08:11 AM polprog: wow why the hell did they put a microcontroller there
08:11 AM polprog: since the NXP chip already does serial
08:12 AM polprog: i assumed it talks over SPI or I2C
08:12 AM rue_mohr: $$?
08:12 AM rue_mohr: part of the reason I got this one is cuase its just serial
08:13 AM polprog: that doesnt make sense it only makes it *more* expensive
08:13 AM polprog: nop, looks like the RC522 is SPI
08:13 AM polprog: https://pl.aliexpress.com/item/1005005995095290.html
08:13 AM polprog: heres a module with just the chip
08:13 AM rue_mohr: lots of them are
08:14 AM rue_mohr: there is a NFC lib in the debain repo
08:16 AM rue_mohr: its kinda funny they put the programming header on
08:16 AM polprog: oh haha they did
08:16 AM polprog: well, sdcc supports stm8 and they are pretty neat little cisc microcontrollers
08:17 AM rue_mohr: so, the idea is to hook it up to a ttl->usb serial module and use it with a PC
08:17 AM rue_mohr: so your thinking its just a protocol bridge eh/
08:18 AM rue_mohr: the ground plane inside the loop probably doesn't help it
08:19 AM rue_mohr: minicom has a binary mode, I'll try things
08:20 AM polprog: the cheap chinese readers
08:21 AM polprog: these black ones
08:21 AM polprog: https://pl.aliexpress.com/item/1005005265276034.html
08:21 AM rue_mohr: its funny, if you get them with a usb serial port built in, they cost a LOT more
08:21 AM polprog: they just pretend to be a keyboard and type the tag ID
08:21 AM polprog: they are read only
08:21 AM rue_mohr: yea, I need RW
08:21 AM polprog: the PC/SC ones are a bit more expensive but you can use the PC/SC library in Linux to write cards
08:21 AM rue_mohr: iirc like $35
08:22 AM polprog: yeah
08:22 AM polprog: so these ones with the interface chips might be easier to use
08:22 AM polprog: and cheaper
08:22 AM polprog: and im 90% sure they write
08:23 AM rue_mohr: I'll play with this
08:23 AM polprog: but uncle gave me a proxmark 3 so I dont need any other RFID readers, that is a swiss knife
08:23 AM polprog: does everything but the UHF 800MHz tags
08:23 AM rue_mohr: oof
08:23 AM polprog: i use it mostly to copy the door opener chips
08:23 AM polprog: for the 13MHz tags i use my phone as most of them are mifare classic
08:24 AM polprog: bbl, gotta give sis a lift
08:24 AM polprog: the warsaw bus tickets are mifare classic :)
08:24 AM polprog: all cards have the same keys
08:24 AM rue_mohr: ewww we had snow
08:24 AM polprog: the ticket format was cracked ages ago
08:24 AM polprog: they now added some random field that changes every validation
08:24 AM polprog: BBL
08:28 AM rue_mohr: if I CAN get t work...
07:49 PM rue_mohr: so
07:49 PM rue_mohr: that wireless FPV goggle set I got
07:49 PM rue_mohr: the transmitter takes normal composite video
07:50 PM rue_mohr: so, I realized that with a converter, I can use it to watch the computer while I work on breadboards
07:50 PM rue_mohr: cause there have been challanges there
07:50 PM rue_mohr: mostly the bench isn't big enough for me, the project, and the computer
07:50 PM rue_mohr: and a keyboard