notes on setting up production unit

experiment/production/GPRS-GPS-notes.md

@@ -0,0 +1,124 @@
+Raspberry Pi GPRS/GPS notes
+===
+
+I'm focusing on a SIM4320(A) chip:
+
+* [Adafruit](https://www.adafruit.com/product/2687)
+  - [simcom](https://cdn-shop.adafruit.com/datasheets/SIMCOM_SIM5320_ATC_EN_V2.02.pdf)
+  - [sim4320 datasheet](https://www.tinyosshop.com/datasheet/SIM5320_Hardware+Design_V1.07.pdf)
+* [DIYmall](https://www.amazon.com/gp/product/B06Y3N1BD6)
+* [Arduino SIM5320A](https://www.amazon.com/gp/product/B01HNV3ZXC)
+
+GPRS
+---
+
+| Raspberry Pi Pin | FONA Pin |
+|---|---|
+| 3.3v (1) | Vio (4) |
+| GND (6) | GND (3) |
+| TXD (8) | RX (6) |
+| RXD (10) | TX (7) |
+
+On the Raspberry Pi (RPi 3B+, Raspbian 2019-07-10 Buster)
+
+```
+sudo bash
+apt-get update
+apt-get install ppp screen minicom
+
+# disable rpi serial interface so we can use it from FONA
+#
+echo 'enable_uart=1' >> /boot/config.txt
+
+# setup ppp configuration
+#
+cat > /etc/ppp/peers/fona <<EOF
+connect "/usr/sbin/chat -v -f /etc/chatscripts/gprs"
+/dev/serial0
+115200
+noipdefault
+usepeerdns
+defaultroute
+persist
+noauth
+nocrtscts
+local
+EOF
+shutdown -r now
+```
+
+At this point, after reboot, I tested to make sure the serial connection was at least responding to `AT` commands:
+
+```
+sudo bash
+minicom -c on -D /dev/serial0
+AT
+```
+
+* The `AT` command should show up because the FONA should echo the commands
+* The FONA should respond with `OK`
+
+I **think** I only had to add the `enable_uart=1` in the `/boot/config.txt` and wire the serial connection
+for this to work...
+
+---
+
+To setup a `ppp` connection, issuing:
+
+```
+pon fona
+```
+
+as root should work.
+
+If there are troubles, look at `dmesg` and `/var/log/syslog` for clues as to what went wrong.
+
+---
+
+* After setup, I'm having trouble with `wwan0`. Doing `ifconfig wwan0 down` and then resetting the `ppp` connection
+  (`poff fona ; pon fona`), I get internet connectivity.
+* I have to physically hold down the 'on' button for 5s to turn on the GPRS and GPS functionality
+
+GPS
+---
+
+I'm using an active antennae.
+
+I've soldered the 'bias' bin on the 3G Fona module.
+
+Note that I couldn't find any reference on Adafruit's site about soldering the 'bias' bridge.
+I only found this information when looking at other users problems ([src](https://forum.core-electronics.com.au/t/adafruit-fona-gps-not-working/644/8)).
+It turns out Adafruit does mention it in one of their PDF guides ([src](https://cdn-learn.adafruit.com/downloads/pdf/adafruit-fona-3g-cellular-gps-breakout.pdf)).
+
+There is a USB connection to the FONA which is how, I believe, the `ttyUSB` interfaces are coming up.
+The USB to serial connection can be used for the GPS information whereas the direct serial connection
+is used for the GPRS modem.
+
+* I was not getting a fix on the satellites until I soldered the 'bias' bridge on the FONA.
+* I had to reseat the small GPS antennae connector
+* Connect to serial interface via `/dev/ttyUSB3`
+  - Note that `/dev/ttyUSB2` looks to be another viable candidate but maybe what goes on in `/dev/ttyUSB3` is mirrored
+    in `/dev/ttyUSB2`
+  - `/dev/ttyUSB0` and `/dev/ttyUSB1` show up when the FONA is powered on but I haven't been able to get any response
+    when connecting via `minicom` to either of those interfaces
+  - to connect from the command line `minicom -c on -D /dev/ttyUSB2` (8N1 115200, hardware flow control off)
+* Turn on the GPS functionality by issuing `AT+CGPS=1`
+* To poll every 3 seconds with full NMEA message output, issue `AT+CGPSINFOCFG=3,31`
+  - Look for the `$GPRMC,...` line as that has the easiest to read lat/lon positions
+
+See [NMEA sentence information](http://aprs.gids.nl/nmea/) and 
+
+References
+---
+
+* [Initial State tutorial](https://github.com/initialstate/fona-raspberry-pi-3/wiki)
+* [Adafruit FONA tethering tutorial](https://learn.adafruit.com/fona-tethering-to-raspberry-pi-or-beaglebone-black/overview)
+* [Adafruit FONA 3G tutorial](https://learn.adafruit.com/adafruit-fona-3g-cellular-gps-breakout/overview)
+* [Disabling serial port](https://www.cube-controls.com/2015/11/02/disable-serial-port-terminal-output-on-raspbian/)
+* [Disable WiFi and Bluetooth](https://blog.sleeplessbeastie.eu/2018/12/31/how-to-disable-onboard-wifi-and-bluetooth-on-raspberry-pi-3/)
+* [SO: How do I make serial work on ...](https://raspberrypi.stackexchange.com/questions/45570/how-do-i-make-serial-work-on-the-raspberry-pi3-pi3b-pizerow)
+* [GPS - NMEA sentence information](http://aprs.gids.nl/nmea/)
+* [NMEA-0183 messages: Overview](https://www.trimble.com/OEM_ReceiverHelp/V4.44/en/NMEA-0183messages_MessageOverview.html)
+* [Adafruit picture of FONA (see soldered bridge with active antenaae)](https://cdn-learn.adafruit.com/assets/assets/000/027/349/original/adafruit_products_Fona_America_top_demo_ORIG.jpg?1440189319)
+* [GH: Adafruit FONA Simcom 3G Breakout PCB](https://github.com/adafruit/Adafruit-FONA-SIMCOM-3G-Breakout-PCB)
+* [Simcom SIM5320 AT command set](https://cdn-shop.adafruit.com/datasheets/SIMCOM_SIM5320_ATC_EN_V2.02.pdf)

experiment/production/Misc-Notes.md

@@ -0,0 +1,72 @@
+Misc. Notes
+===
+
+* [Raspberry Pi Configuration](https://www.raspberrypi.org/documentation/configuration/)
+
+Custom Splash Screen
+---
+
+[src](https://yingtongli.me/blog/2016/12/21/splash.html)
+
+In `/boot/config.txt`, add:
+
+```
+disable_spash=1
+```
+
+optionally:
+
+```
+disable_overscan=1
+```
+
+---
+
+In `/boot/cmdline.txt`, add:
+
+```
+logo.nologo consoleblank=0 loglevel=1 quiet
+```
+
+---
+
+By hand run
+
+```
+systemctl disable getty@tty1
+```
+
+---
+
+```
+apt install fbi
+```
+
+Create `/etc/systemd/system/splashscreen.service`:
+
+```
+[Unit]
+Description=Splash screen
+DefaultDependencies=no
+After=local-fs.target
+
+[Service]
+ExecStart=/usr/bin/fbi -d /dev/fb0 --noverbose -a /opt/splash.png
+StandardInput=tty
+StandardOutput=tty
+
+[Install]
+WantedBy=sysinit.target
+```
+
+With `/opt/splash.png` 
+
+---
+
+Might need to kill `fbi` when starting the kiosk.
+
+### Other References
+
+*  [cmdline.txt](https://www.raspberrypi.org/documentation/configuration/cmdline-txt.md)
+
+

experiment/production/Production-Overview.md

@@ -0,0 +1,29 @@
+Production Unit Development Overview
+===
+
+This is a document recording notes for the path to creating a working production unit.
+
+Hardware
+---
+
+* Get SIM5320A GPRS/GPS working
+  - Need to automatically start and connect on boot
+  - Need to confirm GPRS antennae and GPS antennae work inside or at other positions
+    in housing
+  - GPRS needs to have some pin tied for automatic power on (potentially rpi controlled)
+* Connect/stack SIM5320A in line with screen
+  - make sure screen and serial have no physical pin conflicts
+* Make breakout board for power connector
+* Find solution for speaker amplifier
+* Need to figure out case. Stop-gap of retrofitting to current case
+  - New case need only to attach to the four screw configuration already in place for
+    DIU bottom plate
+* Look into brighter screen
+
+Software
+---
+
+* Add 'quick dim' feature to screen
+  - Screensaver will light back up on press
+* Better screen diagnostics
+* Debug/testing of driver interface