TokenPrinter

Getting the sd card ready

• downloaded the buster lite image from raspian website
• Burned the Image using Etcher for Windows (got from the same source)
• Memory card will have 2 partitions now -
  • boot partition (Fat32)
  • Actual OS (Ext4)
• In Windows - only boot partition will be shown
• In Linux - boot partition will be read-only
• I created 2 files in boot partition for enabling ssh and wifi:
  • ssh - empty content
  • wpa_supplicant.conf

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=IN

network={
 ssid="<Name of your WiFi>"
 psk="<Password for your WiFi>"
}

Ref: https://www.raspberrypi.org/documentation/configuration/wireless/headless.md

Connecting to raspi

• Boot up the raspi(and waited for sometime) and checked its entry in the router's Ip table to find out its ip (knowing their MAC in advance will also help)
• ssh pi@192.168.0.102 (ip found from the previous step)
• sudo apt-get update; sudo apt-get -y upgrade
• raspi-config -> Interface settings -> enable VNC (optional)
• raspi-config -> Localisation Options -> Change Timezone -> Asia -> Kolkata

Setup Real Time Clock - DS3231

• Connect the I2C pins of RTC to pin 3(GPIO 8),5(GPIO 9) of rPi, Vcc and Gnd to pin 1,7 of rPi
• sudo nano /etc/modules # and append at the end

  rtc-ds1307

• sudo apt-get install i2c-tools
• sudo i2cdetect -y 1
• sudo nano /etc/rc.local # and append before exit 0

  echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
  hwclock -s

• sudo reboot
• check date
• to write the correct time to RTC sudo hwclock -w

Ref: https://www.raspberrypi-spy.co.uk/2015/05/adding-a-ds3231-real-time-clock-to-the-raspberry-pi/

Code Setup

• github repo setup and installation

  sudo apt-get install git virtualenv  #Install git and virtualenv
  git clone https://github.com/mgarg1/TokenPrinter.git
  cd TokenPrinter
  virtualenv venv -p python3
  source venv/bin/activate
  pip install -r requirements.txt

• python-escpos setup
  • Ref: https://python-escpos.readthedocs.io/en/latest/user/raspi.html
• python-escpos code needs usb persmissions:

  # give permission to the user for usb:
  sudo groupadd usbusers # create new usergroup
  sudo usermod -a -G usbusers pi # add user pi to the usbusers group
  sudo touch /etc/udev/rules.d/99-usbusers.rules # create this rules file

• contents of /etc/udev/rules.d/99-usbusers.rules

  SUBSYSTEM=="usb", GROUP="usbusers", MODE="0660"
  SUBSYSTEMS=="usb", GROUP="usbusers", MODE="0660"

• sudo init 6 # restart the pi

Ref:https://www.odoo.com/documentation/user/9.0/point_of_sale/overview/setup.html

15. Connect the printer to another USB port of rPi zero i. $ lsusb Bus 001 Device 002: ID 0456:0808 Analog Devices, Inc. ii.
16. python3 main.py

sudo apt-get install python3-rpi.gpio

Install virtualenv

sudo apt-get install python3-virtualenv

Installation on Raspi

sudo apt-get install libjpeg-dev zlib1g-dev
sudo apt-get install python3-rpi.gpio

pip install requirements.txt

Read Only Raspi

Read Only Filesystem : https://learn.adafruit.com/read-only-raspberry-pi

Scheduling restart

• In /etc/rc.local

  
  sudo bash -c 'source /home/pi/TokenPrinter/venv_token/bin/activate && python3 /home/pi/TokenPrinter/main.py' &

<!---
* In `crontab -e` type:
@reboot source /home/pi/TokenPrinter/venv_token/bin/activate && python3 /home/pi/TokenPrinter/main.py
-->
## Circuit Diagram
![Circuit Diagram](static/Circuit_Diagram.png)

## Deployment Photos
![Deployment Photos](static/Deployment_Photos.jpg)

## References
* Stable version(2.20) which I am using - https://github.com/python-escpos/python-escpos/tree/cbe38648f50dd42e25563bd8603953eaa13cb7f6
* Docs for this version - https://python-escpos.readthedocs.io/en/v2.2.0/
* GPIO Docs - https://sourceforge.net/p/raspberry-gpio-python/wiki/Inputs/
* https://www.programiz.com/python-programming/datetime/strftime
* https://github.com/PyramidTechnologies/Phoenix-ESC-POS
* Backup using Win32 Disk Imager https://www.howtogeek.com/341944/how-to-clone-your-raspberry-pi-sd-card-for-foolproof-backup/

### Espson references
* https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=118#dle_eot
* https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=124#gs_lr
* https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=205
* https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=185#dle_enq