BBB PractiScore Printer

Outstanding issues

• What to do about time/date if NTP not available (RTC on adapter card?)
• Soft or hard power switch?
• EEPROM for cape ID?

Controls and indicators

• Indicators

• Fault/OK (bi-color red/green)
• Charging/Battery warning (bi-color red/green)

• Switches

• Power on/off (toggle or PB?)
• AP/client mode select (toggle or PB?)
• Reprint last job/print statistics (PB, short press/long press)

Behaviors

• Print PractiPrint version at power on
• Print Linux version, other useful info at power on
• Print network status on power on or network status change
• Print low-battery warning when battery low

Operation

Misc

• Printer advertises self via mDNS (avahi)
• URL request to CGI app prints information (PractiPrint)
• Last PractiPrint output can be reprinted with reprint button
• Status of printer (sign-on info + list of last 10 print jobs) printed with long-press of reprint button
• Status of printer (sign-on info + all print jobs since power on) is available on root web page

WiFi

• When printer is an AP or has associated as client, fault/OK led is solid green
• When printer is client and is associating, fault/OK led flashes yellow
• When printer is out of paper, fault/OK light is blinks red (pattern?)
• When printer cannot be detected by application (ESC-v), fault/OK light is solid red
• When printer is an AP, NTP server is active
• When printer is a client, NTP client mode is active

Battery

• When LiFePo/SLA battery is charged, battery LED is solid green
• When LiFePo/SLA battery is charging, battery LED blinks green (pattern?)
• When printer is operating on battery power, battery LED is solid yellow
• When LiFePo/SLA battery is at low voltage, battery LED blinks red (pattern?)
• When LiFePo/SLA battery is at dead threshold, battery LED is solid red (BBB starts shutdown)

Adapter card ("cape")

• Buck/boost power supply for input power (12V/3A)
• LiFePo/SLA battery charging via LTC-4000
• 9V/2A switching power supply for printer
• 5V/2A switching power supply for BBB
• LED drivers for fault/OK and battery LEDs (plus 2 spares)
• Buffered input for switches (AP/client, reprint, 2 spares)
• Serial/power connector for printer
• Cape EEPROM (?)
• RTC (DS3232)