diff --git a/README.md b/README.md index 912f46f..ae0db74 100644 --- a/README.md +++ b/README.md @@ -1,23 +1,27 @@ # Rotary Phone Audio Guestbook -This project transforms a rotary phone into a voice recorder for use at special events (i.e. wedding audio guestbook, etc.). - - [Rotary Phone Audio Guestbook](#rotary-phone-audio-guestbook) - [Background](#background) - [Post-Event](#post-event) - - [Future Potential](#future-potential) + - [Future Work (Action Items)](#future-work-action-items) - [Materials](#materials) - - [Setup](#setup) - - [Hardware](#hardware) - - [Wiring](#wiring) - - [Microphone Replacement (Optional)](#microphone-replacement-optional) - - [Software](#software) - - [Dev Environment](#dev-environment) - - [Dependencies](#dependencies) - - [AudioInterface Class](#audiointerface-class) - - [rotaryGuestBook.service](#rotaryguestbookservice) - - [Operation Mode 1: rotaryGuestBook](#operation-mode-1-rotaryguestbook) - - [Operation Mode 2: rotaryGuestBookwithRotaryDialer](#operation-mode-2-rotaryguestbookwithrotarydialer) + - [Hardware](#hardware) + - [Wiring](#wiring) + - [Hook](#hook) + - [Phone Cord](#phone-cord) + - [Microphone Replacement (Optional)](#microphone-replacement-optional) + - [Software](#software) + - [Dev Environment](#dev-environment) + - [Dependencies](#dependencies) + - [Config](#config) + - [AudioInterface Class](#audiointerface-class) + - [audioGuestBook systemctl service](#audioguestbook-systemctl-service) + - [Operation Mode 1: audioGuestBook](#operation-mode-1-audioguestbook) + - [Operation Mode 2: audioGuestBookwithRotaryDialer](#operation-mode-2-audioguestbookwithrotarydialer) + +This project transforms a rotary phone into a voice recorder for use at special events (i.e. wedding audio guestbook, etc.). + +![image](images/final_result_2.jpg) ## Background @@ -27,13 +31,15 @@ Below you will find a parts list and detailed setup guide. Please feel free to r ## Post-Event -Since this was a trial by fire type of scenario there ended up being a few gotchas at the real event which I've since accounted for. Namely setting a time limit on the recording length as we had some youngsters leaving 5+ minute messages repeatedly and this ended up draining the battery. +Since this was a trial by fire type of scenario there ended up being a few gotchas at the real event which I've since accounted for. Namely setting a time limit on the recording length as we had some youngsters leaving 5+ minute messages repeatedly and this ended up draining the battery. Alternatively, depending on your scenario, it might be preferable to attach directly to a 5V power supply. -### Future Potential +### Future Work (Action Items) -A few weeks before the wedding I had the code registering dialed numbers from the rotary encoder with the goal of playing back special messages for certain guests who dialed a certain combination (i.e. dial an area code to hear a special message to my old roomates). The details of this operation mode are described in Mode 2 below. In order to activate this mode I had to wait for input when the phone was off the hook. This required an extra step of dialing zero before leaving a normal voice message. In the end we decided to keep it simple and I've thus migrated this code to the dev branch along with the code to run through post-porcessing the audio in a separate process. +A few weeks before the wedding I had the code registering dialed numbers from the rotary encoder with the goal of playing back special messages for certain guests who dialed a certain combination (i.e. dial an area code to hear a special message to my old roomates). The details of this operation mode are described in [Mode 2](#operation-mode-2-rotaryguestbookwithrotarydialer) below. In order to activate this mode I had to wait for input when the phone was off the hook. This required an extra step of dialing zero before leaving a normal voice message. In the end we decided to keep it simple and I've thus migrated this code to the dev branch along with the code to run through post-porcessing the audio in a separate process. If any one is interested in expanding this please feel free. +I would also like to thread the audio playback so I can have a monitor/watchdog service terminate the thread upon hook callback so that the message doesn't continue playing once the user hangs up. + ## Materials | Part|Notes|Quantity|Cost| @@ -44,6 +50,8 @@ If any one is interested in expanding this please feel free. | [micro SD card](https://a.co/d/1gb2zhC) | Any high capacity/throughput micro SD card that is rpi compatible | 1 | $8.99 | | [USB Audio Adapter](https://www.adafruit.com/product/1475) | Note: I removed the external plastic shell and directly soldered the wires instead of using the female 3.5mm receptacle. | 1 | $4.95 | | [USB OTG Host Cable - MicroB OTG male to A female](https://www.adafruit.com/product/1099) | | 1 | $2.50 | +| --- | **--- If you don't want to solder anything ---** | --- | --- | +| [3.5mm Male to Screw Terminal Connector](https://www.parts-express.com/3.5mm-Male-to-Screw-Terminal-Connector-090-110?quantity=1&utm_source=google&utm_medium=cpc&utm_campaign=18395892906&utm_content=145242146127&gadid=623430178298&gclid=CjwKCAiAioifBhAXEiwApzCztl7aVb18WP4hDxnlQUCHsb62oIcnduFCSCbn9LFkZovYTQdr6omb3RoCD_gQAvD_BwE) | Optional: can connect the handset cables directly to the USB audio interface via these screw terminals | 2 | $1.37 | | --- | **--- If running off a battery ---** | --- | --- | | [LiPo Battery](https://www.adafruit.com/product/2011)| Optional: maximize capacity based on what will fit within your rotary enclosure. |1| $12.50 | | [LiPo Shim](https://www.adafruit.com/product/3196)| Optional: if you plan to run this off a LiPo I would recommend something like this to interface with the rpi zero. |1| $9.95 | @@ -51,13 +59,43 @@ If any one is interested in expanding this please feel free. | --- | **--- If replacing the built-it microphone ---** | --- | --- | | [LavMic](https://www.amazon.com/dp/B01N6P80OQ?ref=nb_sb_ss_w_as-reorder-t1_ypp_rep_k3_1_9&=&crid=15WZEWMZ17EM9&=&sprefix=saramonic) | Optional: if you'd like to replace the carbon microphone. This is an omnidirectional lavalier mic and outputs via a 3.5mm TRS | 1 | $24.95 | -## Setup +## Hardware -### Hardware +### Wiring -#### Wiring +#### Hook -#### Microphone Replacement (Optional) +- Use multimeter to do a continuity check to find out which pins control the hook: + +| On-hook --> Open circuit (Value == 1) | Off-hook --> Current flowing | +| ------------- | ------------- | +| ![image](images/hook_test_1.jpg) | ![image](images/hook_test_2.jpg) | + +- The B screw terminal on the rotary phone is connected to the black wire which is grounded to the rpi. +- The L2 screw terminal on the rotary phone is connected to the white wire which is connected to GPIO pin 22 on the rpi. + + ![image](images/pi_block_terminal_wiring.jpg) + +- *Note: the green wire was used for the experimental rotary encoder feature identified in the [future work](#future-work-action-items) section.* + +| Rotary Phone Block Terminal | Top-down view | +| ------------- | ------------- | +| ![image](images/block_terminal.jpg) | ![image](images/top_view_block_terminal.jpg) | + +#### Phone Cord + +- The wires from the handset cord need to be connected to the USB audio interface + - I soldered it but you can alternatively use 2x [3.5mm Male to Screw Terminal Connector](https://www.parts-express.com/3.5mm-Male-to-Screw-Terminal-Connector-090-110?quantity=1&utm_source=google&utm_medium=cpc&utm_campaign=18395892906&utm_content=145242146127&gadid=623430178298&gclid=CjwKCAiAioifBhAXEiwApzCztl7aVb18WP4hDxnlQUCHsb62oIcnduFCSCbn9LFkZovYTQdr6omb3RoCD_gQAvD_BwE) which plug directly into the rpi. + - *Note: The USB audio interface looks weird in the pics since I stripped the plastic shell off in order to solder directly to the mic/speaker leads* + +![image](images/dissected_view_1.jpg) + +- Use this ALSA command from the command line to test if the mic is working on the rpi before you set up the rotary phone: `aplay -l` + - You might have a different hardware mapping than I did, in which case you would change the `alsa_hw_mapping` in the [config.yaml](config.yaml). + - [Here's](https://superuser.com/questions/53957/what-do-alsa-devices-like-hw0-0-mean-how-do-i-figure-out-which-to-use) a good reference to device selection. + - You can also check [this](https://stackoverflow.com/questions/32838279/getting-list-of-audio-input-devices-in-python) from Python. + +### Microphone Replacement (Optional) I found the sound quality of the built-in [carbon microphone](https://en.wikipedia.org/wiki/Carbon_microphone) on the rotary phone to be quite lacking in terms of amplitude, dynamic range and overall vocal quality. I tried boosting the gain from the digital (ALSA driver) side but this introduced an incredible amount of noise as expected. I then approached this from the analog domain and tried alternative circuitry to boost the sound quality based off this [carbon-to-dynamic converter](https://www.circuits-diy.com/mic-converter-circuit/). @@ -70,12 +108,21 @@ To replace: - Unscrew mouthpiece and remove the carbon mic - Pop out the plastic terminal housing with the two metal leads - Unscrew red and black wires from terminal +- Prepare your lav mic + - I pulled off the 3.5mm male headphone pin since it is usually coated and annoyingly difficult to solder directly on to. + - Carefully separate the two wires from the lav mic and spiral up the surrounding copper. This will act as our ground signal. +- Extend the green wire from the phone cord clip to the ground point of the lav mic. +- Red to red, black to blue as per the following diagram: -![image](images/phone2.jpg) +![image](images/phone_wiring.jpg) -### Software +![image](images/handset_mic_wiring.jpg) -#### Dev Environment +![image](images/handset_mic_positioning.jpg) + +## Software + +### Dev Environment - rpi image: [Rasbian](https://www.raspberrypi.com/documentation/computers/getting-started.html) w/ SSH enabled - rpi on same network as development machine @@ -83,7 +130,7 @@ To replace: [Here's](https://jayproulx.medium.com/headless-raspberry-pi-zero-w-setup-with-ssh-and-wi-fi-8ddd8c4d2742) a great guide to get the rpi setup headless w/ SSH & WiFi dialed in. -#### Dependencies +### Dependencies - `pip3 install -r requirements.txt` or pip install each manually: - [GPIOZero](https://gpiozero.readthedocs.io) @@ -91,22 +138,44 @@ To replace: - [PyAudio](https://people.csail.mit.edu/hubert/pyaudio/) - [PyYAML](https://pyyaml.org/) -#### [AudioInterface Class](audioInterface.py) +### [Config](config.yaml) -#### [rotaryGuestBook.service](rotaryGuestBook.service) +- This file allows you to customize your own set up (edit rpi pins, audio reduction, alsa mapping, etc), modify the yaml as necessary. + +- For GPIO mapping, refer to the wiring diagram specific to your rpi: + ![image](images/rpi_GPIO.png) + +### [AudioInterface Class](audioInterface.py) + +- Utilizes pydub and pyaudio extensively. +- Houses the main playback/record logic and has future #TODO expansion for postprocessing the audio. Would like to test on an rpi4 to see if it can handle it better for real-time applications. + +#### [audioGuestBook systemctl service](/audioGuestBook.service) This service starts the python script on boot. Place it in the `/etc/systemd/system` directory. -`systemctl enable audioGuestBook.service` -`systemctl start audioGuestBook.service` +```sh +systemctl enable audioGuestBook.service +systemctl start audioGuestBook.service +``` +### Operation Mode 1: [audioGuestBook](/audioGuestBook.py) -#### Operation Mode 1: [rotaryGuestBook](rotaryGuestBook.py) +- This is the main operation mode of the device. +- There are two callbacks in main which poll the gpio pins for the specified activity (hook depressed, hook released). +- Once triggered the appropriate function is called. +- On hook (depressed) + - Nothing happens +- Off hook (released) + - Plays back your own welcome message located in `/sounds/voicemail.wav` followed by the beep indicating ready to record. + - Begins recording the guests voice message. + - Guest hangs up, recording is stopped and stored to the `/recordings/` directory. -#### Operation Mode 2: [rotaryGuestBookwithRotaryDialer](rotaryGuestBookwithRotaryDialer.py) +### Operation Mode 2: [audioGuestBookwithRotaryDialer](./todo/audioGuestBookwithRotaryDialer.py) ***Note*:** Untested - decided not to go this route for my own wedding - This mode is a special modification of the normal operation and requires a slightly different wiring connection since it accepts input from the rotary dialer. - The idea was to playback special messages when particular users dial a certain number combination (i.e. 909 would play back a message for certain guests who lived with the groom in that area code). - In this mode of operation the users will need to dial 0 on the rotary dialer in order to initiate the voicemail. +- The rotary dialer is a bit more complex to set up, you need a pull up resistor connected between the F screw terminal and 5V on the rpi and the other end on GPIO 23. #TODO: Diagram diff --git a/images/PXL_20221127_191822432.jpg b/images/block_terminal.jpg similarity index 100% rename from images/PXL_20221127_191822432.jpg rename to images/block_terminal.jpg diff --git a/images/PXL_20221127_191801539.jpg b/images/dissected_view_1.jpg similarity index 100% rename from images/PXL_20221127_191801539.jpg rename to images/dissected_view_1.jpg diff --git a/images/PXL_20221127_191808218.jpg b/images/dissected_view_2.jpg similarity index 100% rename from images/PXL_20221127_191808218.jpg rename to images/dissected_view_2.jpg diff --git a/images/final_result.jpg b/images/final_result.jpg new file mode 100644 index 0000000..4688d29 Binary files /dev/null and b/images/final_result.jpg differ diff --git a/images/final_result_2.jpg b/images/final_result_2.jpg new file mode 100644 index 0000000..b0a3c47 Binary files /dev/null and b/images/final_result_2.jpg differ diff --git a/images/PXL_20221127_191903412.jpg b/images/handset_mic_positioning.jpg similarity index 100% rename from images/PXL_20221127_191903412.jpg rename to images/handset_mic_positioning.jpg diff --git a/images/PXL_20221217_193545205.jpg b/images/handset_mic_wiring.jpg similarity index 100% rename from images/PXL_20221217_193545205.jpg rename to images/handset_mic_wiring.jpg diff --git a/images/hook_test_1.jpg b/images/hook_test_1.jpg new file mode 100644 index 0000000..79bd77f Binary files /dev/null and b/images/hook_test_1.jpg differ diff --git a/images/hook_test_2.jpg b/images/hook_test_2.jpg new file mode 100644 index 0000000..a3d402e Binary files /dev/null and b/images/hook_test_2.jpg differ diff --git a/images/phone2.jpg b/images/phone_wiring.jpg similarity index 100% rename from images/phone2.jpg rename to images/phone_wiring.jpg diff --git a/images/pi_block_terminal_wiring.jpg b/images/pi_block_terminal_wiring.jpg new file mode 100644 index 0000000..30dcdfe Binary files /dev/null and b/images/pi_block_terminal_wiring.jpg differ diff --git a/images/Raspberry-Pi-GPIO-Header-with-Photo-1024x683.png b/images/rpi_GPIO.png similarity index 100% rename from images/Raspberry-Pi-GPIO-Header-with-Photo-1024x683.png rename to images/rpi_GPIO.png diff --git a/images/PXL_20221127_191828405.jpg b/images/top_view_block_terminal.jpg similarity index 100% rename from images/PXL_20221127_191828405.jpg rename to images/top_view_block_terminal.jpg