3 types of RFID cards:
- 125kHz/134kHz Low Frequency (LF) ... najčešće okrugla antena
- 13.56Mhz High Frequency (HF) ... najčešće pravokutna oko ruba
- Ultra High Frequency (UHF)
125kHz starije, uglavnom samo ID
chinese magic cards – cards with changable ID
proxmark3 – for analysing and hacking
pn532 vs rc522 differences:
- pn532 bolji range
- rc522 bolji library
convert -density 150 input.pdf -rotate "$([ $((RANDOM % 2)) -eq 1 ] && echo -)0.$(($RANDOM % 4 + 5))" -attenuate 0.4 +noise Multiplicative -attenuate 0.03 +noise Multiplicative -sharpen 0x1.0 -colorspace Gray output.pdf
Fuzzy bits
Fuzzy bit
The whole problem was the following.....
It was a ground problem
It is weird
But the problem was, for one, we need to GND both GND pins
Lastly, the GND of the data wire to the amp must be as close as to the GND pin of the DFPlayer
So, we cannot just plug the GND data wire into GND. It has to be like next to the pin of GND on the DFPlayer
I pulled the GND out of the GND that is between the SPK 1 and SPK 2 and instead just left the GND of the data wire there. I think that is how it is suppose to be
The GND on the other side is to be plugged into the negative terminal
What remains is a hum, not a bep bep bep bep, but the hum is much more tolerable.
