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Bruce Schubert edited this page Sep 14, 2020 · 16 revisions

Call Attendant

Contents

  1. Run as a Service
  2. LED Indicators
  3. Record Audio Files

Run as a Service

We're going to define a service to automatically run the Call Attendant on the Raspberry Pi at start up. Our simple service will run the callattendant.py script and if by any means is aborted it is going to be restarted automatically.

Create the Service

Step 1. Create the Unit File

The service definition unit file must be on the /lib/systemd/system folder. Our service is going to be called "callattendant.service".

But first, we must identify the path to the callattendant command. Use the which command to locate the callattendant script. Note the path, we'll use it later in the unit file.

which callattendant
/home/pi/.local/bin/callattendant

Now create the unit file using the nano editor:

sudo nano /lib/systemd/system/callattendant.service

Copy the following text into the callattendant.service unit file; edit the paths as necessary for your system using path identified earlier. You can use Ctl-Shift-V or Right-Click > Paste to paste this text into the nano editor.

[Unit]
Description=Call Attendant
After=multi-user.target

[Service]
Type=simple
ExecStart=/home/pi/.local/bin/callattendant --config app.cfg
Environment="PYTHONUNBUFFERED='True'"
WorkingDirectory=/home/pi/.callattendant
User=pi
Restart=on-abort

[Install]
WantedBy=multi-user.target

You can check more on service's options in the next wiki: https://wiki.archlinux.org/index.php/systemd.

Step 2. Activate the Service

Now that we have our service we need to activate it:

# Change the permissions on the service file to read/write
sudo chmod 644 /lib/systemd/system/callattendant.service

# Reload the unit files
sudo systemctl daemon-reload

# Enable the service...
sudo systemctl enable callattendant.service

# And now run the service
sudo systemctl start callattendant.service

Service Tasks

For every change that we do on the /lib/systemd/system folder we need to execute a daemon-reload (third line of previous code). Execute the following commands as needed to check the status, start and stop the service, or check the logs.

# Reload the unit file(s)
sudo systemctl daemon-reload

Start service

# Use the supplied command script
start-callattendant

# or use the system command
sudo systemctl start callattendant.service

Stop service

# Use the supplied command script
stop-callattendant

# or use the system command
sudo systemctl stop callattendant.service

Check/Monitor service's log

# Use the supplied command script
monitor-callattendant

# or use the system command
sudo journalctl -f -u callattendant.service

Check status

sudo systemctl status callattendant.service

REFERENCES

LED Indicators

I built a custom Raspberry Pi HAT to show the callattendant's status with several LEDs.

prototype

  • A blinking orange LED indicates an incoming call
  • A blinking green LED indicates a permitted/approved caller: Get up and answer the phone.
  • A blinking red LED indicates a blocked/denied caller: Stay seated.
  • A pulsing blue LED indicates unplayed messages are waiting; blinking means the caller is in the voice messaging menu; steady means a message is being recorded.
  • A 7-segment LEG shows the number of unplayed messages that are waiting

Configuration values

# GPIO_LED_MESSAGE_COUNT_PINS: This is a tuple containing the GPIO pins for the 7-segment LED
#   ordered by segment as thus: (a, b, c, d, e, f, g, dp)
# GPIO_LED_MESSAGE_COUNT_KWARGS: This is a dictionary of optional arguments (used by GPIOZero LEDBoard)
# ================================================================================================
# V2 HAT
GPIO_LED_MESSAGE_COUNT_PINS = (8, 7, 27, 23, 10, 11, 9, 18)
GPIO_LED_MESSAGE_COUNT_KWARGS = {"active_high": True}
# ================================================================================================
# V1 HAT
GPIO_LED_MESSAGE_COUNT_PINS = (11, 8, 25, 5, 18, 9, 7, 27)
GPIO_LED_MESSAGE_COUNT_KWARGS = {"active_high": False}
# ================================================================================================
# Prototype HAT
GPIO_LED_MESSAGE_COUNT_PINS = (10, 9, 8, 7, 4, 23, 11, 17)
GPIO_LED_MESSAGE_COUNT_KWARGS = {"active_high": False}

LED Indicators

LED Color GPIO
Ring ORG GP14
Approved GRN GP15
Blocked RED GP17
Message BLU GP4

Kingbright LED Segments

Message Count Indicator

Segment Pin
a 1
f 2
dp 6
e 7
d 8
c 10
g 11
b 13

Assembly

I used the following prototype board to solder up the LEDs and connect them to the GPIO pins: DIGOBAY 3pcs Prototype Breakout Shield PCB Expansion Board Breadboard DIY Kit for Raspberry Pi 4B 3B+ 3B 2B B+ A+. Learn more: https://www.amazon.com/dp/B089M4GFWL/ref=cm_sw_em_r_mt_dp_P1TsFb6PN3ZZA

Diagrams

Following are the Fritzing diagrams for my board:

Empty PCM

PCB

Wiring

wiring

Assembly List
Label Part Type Properties
7 SEG LED Kingbright SA03-12HDB pins 14;
BLU Blue (525nm) LED package 3 mm [THT]; color Blue (525nm);
GRN Green (555nm) LED package 3 mm [THT]; color Green (555nm);
ORG Orange (620nm) LED package 3 mm [THT]; color Orange (620nm);
RED Red (633nm) LED package 3 mm [THT]; color Red (633nm);
R1 15Ω Resistor bands 4; package THT; tolerance ±5%; resistance 15Ω; pin spacing 400 mil
R2 15Ω Resistor bands 4; package THT; tolerance ±5%; resistance 15Ω; pin spacing 400 mil
R3 56Ω Resistor bands 4; package THT; tolerance ±5%; resistance 56Ω; pin spacing 400 mil
R4 56Ω Resistor bands 4; package THT; tolerance ±5%; resistance 56Ω; pin spacing 400 mil
R5 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R6 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R7 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R8 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R9 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R10 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R11 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
R12 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil
Shopping List
Amount Part Type Properties
1 Kingbright SA03-12HDB pins 14;
1 Blue (525nm) LED package 3 mm [THT]; color Blue (525nm)
1 Green (555nm) LED package 3 mm [THT]; color Green (555nm);
1 Orange (620nm) LED package 3 mm [THT]; color Orange (620nm);
1 Red (633nm) LED
2 15Ω Resistor bands 4; package THT; tolerance ±5%; resistance 15Ω; pin spacing 400 mil
2 56Ω Resistor bands 4; package THT; tolerance ±5%; resistance 56Ω; pin spacing 400 mil
8 100Ω Resistor bands 4; package THT; tolerance ±5%; resistance 100Ω; pin spacing 400 mil

Record Audio Files

You can record your own audio wav files for playback to your callers.

See: (https://iotbytes.wordpress.com/play-audio-file-on-phone-line-with-raspberry-pi/)

Add a custom footer

Call Attendant Web Page

  1. Wiki Home
    1. Installation
    2. Configuration
    3. Operation
  2. User Guide
    1. Overview
    2. Navigation
    3. Home Screen
    4. Call History
    5. Viewing Calls
    6. Managing Callers
    7. Voice Messages
    8. Permitted Numbers
    9. Blocked Numbers
  3. Developer Guide
    1. Software Project Setup
    2. Software Architecture
    3. Software Development Plan
    4. Additional Information
  4. Advanced
    1. Run as a Service
    2. LED Indicators
    3. Record Audio Files
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