User:Rando/Ordibooth

Hardware

Raspberry Pi 3 B v1.2

Raspberry Pi Display v1.1

Cannon Powershot A2200

74HC125N partsdb: 1411

software

pi

1. virtualenv

2. virtualenvwrapper

3. pyspacelib (ft interface)

4. python 3.5

4.1 pillow

4.2 pygame

4.3. kivy

Ordi server

1. Imagemagick

2. ptpcam compiled with chdk

3. python 3.5

For some reason, pygame and pillow are not installed with kivy, but are requirements.

for Flask, pip install python-dotenv

CHDK

http://chdk.wikia.com/wiki/CHDK_1.4.0_User_Manual

Download using STICK: http://zenoshrdlu.com/stick/stick.html

Remote Pameters, enable remote

Remote Usage: http://chdk.wikia.com/wiki/USB_Remote

Note: the USB remote functionality is not used for this, we need to control it from the [pi <-> mac] mini device

Scripting

http://chdk.wikia.com/wiki/CHDK_Scripting_Cross_Reference_Page

click

is_key

is_pressed

press

release

shoot

wait_click

wheel_left

wheel_right

Transferring files

How to transfer to computer? Perhaps the rpi can indicate to the macmini to mount the camera and tx the picture.

http://chdk.wikia.com/wiki/PTP_Extension/ptpcam_Examples

ptpcam / libptp

Install instructions

http://chdk.wikia.com/wiki/Ptpcam_in_headless_linux_Dockstar

ok, THIS is the one we want, it has the "ptpcam --chdk" option:

https://github.com/jrabbit/libptp-chdk

notes on usage: http://chdk.wikia.com/wiki/PTP_Extension/ptpcam_Examples

How to run one onn camera:

loadfile('A/CHDK/SCRIPTS/testprgm.lua')()

ordi_controller.py

Handles from ptpcam functions from the mac mini as python calls using subprocess.run.

scripting

http://chdk.wikia.com/wiki/Lua

The "Minimalistic Intervalometer" is a lua script that takes a photo, using half presses and full presses.

Steps:

1. Write script
2. Place <script>.lua in CHDK/SCRIPTS on SD card e.g. A/CHDK/SCRIPTS/testprgm.lua
3. Run script with loadfile('A/CHDK/SCRIPTS/testprgm.lua')()

Script Reference

http://chdk.wikia.com/wiki/CHDK_Scripting_Cross_Reference_Page

How to script and run and stuff

http://chdk.wikia.com/wiki/Lua/PTP_Scripting

> luar shoot()

Lua dev environment metioned here: http://chdk.wikia.com/wiki/Lua_Development_Environment

this is how!

ptpcam --dev=028 --chdk="luar shoot()"

Camera Disassembly

Why? the power doesn't stay on without a button press. so trying to replace the button so we can drive it via a GPIO on the rasp pi.

Wait, why.

Because. We're hacking.

https://www.ifixit.com/Device/Canon_PowerShot_A2200

Power button modification

In order to control the camera power "remotely", the power button was modified to pull out wires and connect them to a GPIO of the pi. This was the power can be turned on when the system boots.

The button was a SMD tact switch with barely exposed pads. In order to get sufficient copper to solder, the solder mask was gently scraped off.

Pi GPIO

Well, pi GPIOs are 3.3V and the typical 3.3V -> 5V doesn't work. The button sense's the ground but the high state does not trigger a high reading on the camera. Since this is the case, it never is released from ground to reset in order to toggle on next "press" aka connection to ground.

Going to put together a simple logic shifter from a diode and a resistor i guess.

Power

The pi needs 5.1V @ 2.5A. That, plus the LCD display max current draw is 400mA, so really need a 3A+ supply.

Ok, after creating a small cable assembly for the power so I can use anything but the USB port, things are stable and the new image installs properly.

Pi Config

the SD card image now boots properly and everything installs.

VNC and ssh access are now enabled.

The inital plan is: 1. GPIO for camera power button 2. Simply kivy UI 3. python camera controller (uses CHDK underneath)

Performance

The pi performance is pretty shit. there's another, bare distribution called devuan to try. Plus I can rip out all the unnecessary UI garbage included in raspbian.

The pi will have to be tuned further. Overclocking is apparently possible, though might need a heatsink/fan, but that's fine.

https://www.raspberrypi.org/forums/viewtopic.php?t=138123

idealy can script the changes and run testing over night or something. Change values, reboot, run benchmark, monitor failures, repeat. How to restart the pi remotely remains a challenge. Might need an arduino hooked up to serial and a small server on the machine. Which is totally fun and cool and can be reused.

other tuning ideas

https://www.makeuseof.com/tag/raspberry-pi-performance-tips/

Pi Image

I'm not sure if I HAVE to create a custom image, but it seems like I should make an attempt in order to load Kivy.

https://www.instructables.com/id/Creating-a-Custom-Shrinked-Raspberry-Pi-Image/

Not really into what that instructables is doing but will keep up.

Next plan: emulate with qemu to get a custom image going

https://stackoverflow.com/questions/38837606/how-to-emulate-raspberry-pi-raspbian-with-qemu

totally custom i think, but like, don't have to.

https://github.com/RPi-Distro/pi-gen

Ok, so to get -M raspi3 natively, qemu currently has to be compiled from scratch. gfd.

https://github.com/qemu/qemu

But it should now include this patch:

https://github.com/bztsrc/qemu-raspi3

Ok, well, this image just wont boot. I'll have to configure the pi by hand which fucking suuuucckkksssssssss

Target Architecture

The pi will run a small kivy based app.

The app will determine and change the state of the camera.

The app will have a button to take a picture.

The app will display the taken picture

The app can delete the pictures

The app can save the picture

The app can preview the picture in the flashen taschen tester

The app can trigger a send of the picture to the flashen taschen.

The app can take in 140 characters of text

The app can send the text to the ordi_server

The app can trigger a tweet the picture

The app will produce a QR code / URL link to retrieve the picture

order server will run on the mac mini

it will be a flask web app with a thin wrapper for commands

the rpi will send commands to the order server

the order sirver will handle all image manipulation

the order server will control the camera

There should ever only be 1 picture on the camera. This picture may include edited versions, so perhaps an object which contains on ordered list of file names. This ordered list will be in editological order, e.g. the lasted edited version should be last, and any throw away edited versions should be trimmed.

Control commands will be send over https to a flask app running on the server. There is one command, on/off, which is required to send to the rpi. As the camera on/off is connected to the GPIO, the server needs to trigger the rpi to enable. This can be turned into a poll using wget, but we'll check performance.

Don't forget

The camera is now open to air. Should print a new enclosure for it since hte button has been, uh...surgically enhanced.