Serial port communication on Mac with SCREEN command

Use screen command to communicate with Serial port

1. Open Terminal or iTerm2
2. See if the serial port exists
   

   $ ls -l /dev/cu.*

   crw-rw-rw-  1 root  wheel   20,   1 Jun 10 21:07 /dev/cu.Bluetooth-Incoming-Port
   crw-rw-rw-  1 root  wheel   20,   3 Jun 12 18:13 /dev/cu.usbmodem1421401
   

3. Connect to the port

   $ screen -L /dev/cu.usbmodem1421401 115200

   -L : show log of the command from the serial port

4. Other commands

   # in a running session
   

   Ctrl-A, K : kill the session
   Ctrl-A, D : detach from the session
   

   # out of session
   

   $ screen -ls : list sessions
   
   There is a screen on:
   9244.ttys001.Dee15S (Attached)
   
   Format : [PID].[TTYID].[HOSTNAME]
   
   $ screen -r : attach the default session
   $ screen -r [NAME] : attach to a session named [NAME]
   $ screen -S [NAME] : attach to a session named [NAME]
   $ screen -d [ID] : detach from the session with screen id [ID]
   

Warning message during R startup on Mac

Got the following warning messages, when run R Studio on Mac.

During startup - Warning messages:
1: Setting LC_CTYPE failed, using "C"
2: Setting LC_COLLATE failed, using "C"
3: Setting LC_TIME failed, using "C"
4: Setting LC_MESSAGES failed, using "C"
5: Setting LC_MONETARY failed, using "C"
>

SOLUTION

1. Open Terminal
2. Run the following command

$ defaults write org.R-project.R force.LANG en_US.UTF-8

KOREAN

$ defaults write org.R-project.R force.LANG ko_KR.UTF-8

FOR SHELL :: .bashrc .bash_profile .zshrc

export LC_ALL=en_US.UTF-8

KOREAN

export LC_ALL=ko_KR.UTF-8

3. Close Terminal
4. Start R Studio again

Paul Graham's Quote

• You need three things to create a successful startup: to start with good people, to make something customers actually want, and to spend as little money as possible.

성공적인 스타트업 만드는 데 필요한 3가지: 좋은 사람들과 시작하기, 고객들이 실제로 원하는 건 만들기, 돈은 적게 쓰기

• A startup is like a mosquito. A bear can absorb a hit and a crab is armored against one, but a mosquito is designed for one thing : to score. No energy is wasted on defense. The defense of mosquitos, as a species, is that there are a lot of them, but this is little consolation to the individual mosquito.

스타트업은 모기와 같다. 곰은 충격을 흡수하고 게는 껍질이 있지만 모기는 한 가지를 위해 만들어졌다. 득점(성공?승리?)하기. 방어에 허비되는 에너지는 없다. 하나의 종으로서 모기의 방어는 수가 많다는 점이지만 개별 모기에게는 아무런 위로가 되지 않는다.

• Don't ignore your dreams; don't work too much; say what you think; cultivate friendships; be happy.

꿈을 무시하지 마라: 너무 많이 일하지 마라; 생각하는 걸 얘기해라; 우정을 쌓아라; 행복해라

• I'm not saying there's no such thing as genius. But if you're trying to choose between two theories and one gives you an excuse for being lazy, the other one is probably right.

천재성이라는 게 없다고 말하지는 않겠다. 그런데 두 가지 이론 중에서 선택하고자 할 때, 그 중 한가지가 당신이 게을러져도 괜찮다고 한다면, 아마도 다른 것이 맞다.

• The most important thing is not to let fundraising get you down. Startups live or die on morale. If you let the difficulty of raising money destroy your morale, it will become a self-fulfilling prophecy.

가장 중요한 것은 자금조달이 당신을 실망시키게 두지 마라. 스타트업은 사기에 죽고 산다. 만약 자금조달의 어려움이 의욕을 꺾는다면, 그것은 자기성취예언(다른 상황들도 악화시키게 됨)이 될 것이다.