Before designing Eagle, I re-tested my FSR sensor with Arduino UNO.
For hole location, I adjusted the routes inner.
As for othermill work, I failed twice; one was caused by weak double-sided tape and the other one was by 1/16 milling bit.
The second mistake was that I used sand paper after printing the board. It turned out the scratch from sand paper really disconnect some part of the circuit.
Letter O was successful.
After few fails, finally it worked. I took a long time comparing with schematic.
During soldering, one of corner was broken 🙁
Also, since I used yellow LEDs and 220 resistors, the brightness was lower than others. In summary, I took many mistakes with this project. But, I could learn a lot of things.