Progress on the RFID

Here is the progress on the RFID System!

When working with SPI, it’s important to consider the RST pin, as when left floating, it could trigger false positives. I didn’t check this pin before, and it was giving me issues with reading from the sensor. Now that that’s fixed, we can successfully read from the RFID chip!

Now, we can read the UID of the device! It’s important to read this UID when first assigning a user, because there are many chances for a UID to be shared between fobs. Doing this ensrues we don’t register two users as the same UID.

After this, I worked on incorporating the Serial receipt printer, which will print on a receipt when the RFID is tapped. To do this, I was using the MAX233 chip, which can take a Serial input/output, and convert it into the RS-232 standard, which is what the Epson Serial Printer interfaces with. The MAX233 makes this very convenient, because it supplies the internal capacitors for generating 10V and -10V required for RS-232.

Right now, I’m working on how to send a message to the serial printer. Simply sending ascii to the printer is not enough, and there are different handshakes required to get it to send data. So far, we got some gibberish printed though!