Little single page webservice that provides control to a simple wallbox.
Since I have a parking space in front of the house, I've decided to buy a small NEV (new energy vehicle) or BEV (battery electric vehicle) and installed a Heidelberg Wallbox Home Eco to charge the battery of the car. It is a simple wallbox (which isn't much more than a fancy three-phase wall outlet) without wifi or electricity meter. Inside of the wallbox two wires can be attached instead of a default wired bridge to control if the wallbox will charge the car or not.
- If the two contacts are closed, the wallbox will charge a connected car.
- if the two contacts are open, no power will be provided.
Simple.
These two wires will be connected to some kind of electronic switch, so that I can control the wallbox from a computer. Even outside the house I am in range of my wifi network, so using a web application to switch the charging on or off seemed a natural choice. No need to fiddle around with an extra key or RFID card.
I could have used an apache web server with some php but where is the fun in that? Rust is the new kid in town and so it was play time :-)
The web server calls external commands to switch the relay, so it could easily be adapted to other relay types or even a Raspberry Pi.
Isn't it a bit overengineered? Yes, it is.
The relay I wanted to use works as a HID device, so that no drivers are necessary, even the current state can be queried.
Stories of usb thumb drives acting as HID device and hacking your computer come to my mind, keep the fingers crossed... :-)
I've installed the usbrelay package on Ubuntu 20.04 LTS and got this infos when executing the command:
usbrelay
Device Found
type: 16c0 05df
path: /dev/hidraw3
serial_number:
Manufacturer: www.dcttech.com
Product: USBRelay1
Release: 100
Interface: 0
Number of Relays = 1
959BI_1=0It works fine on Ubuntu but sadly not with OmniOS, probably because the device uses 0 as protocol and the driver only accepts keyboards and mice.
lsusb -v -d 1d6b:0002
Bus 001 Device 004: ID 16c0:05df Van Ooijen Technische Informatica HID device except mice, keyboards, and joysticks
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x16c0 Van Ooijen Technische Informatica
idProduct 0x05df HID device except mice, keyboards, and joysticks
bcdDevice 1.00
iManufacturer 1 www.dcttech.com
iProduct 2 USBRelay1
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0022
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 20mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0
bInterfaceProtocol 0 <============ there is the culprit
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.01
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 22
Report Descriptors:
** UNAVAILABLE **
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 20
Device Status: 0x0000
(Bus Powered)See the files in the conf.usbhid.prod directory. You may need to run the scripts as root, add sudo to run the usbrelay command as root or add an extra udev rule to use the device as a unprivileged user.
There is an alterative that emulates a serial port. This wasn't my first choice because the few documents I found claimed that it is not possible to query the state of the relay. Therefore I need to store the state which is easy to do but could get out of sync with the real device.
lsusb -v -d 1a86:7523
Bus 001 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 255 Vendor Specific Class
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x1a86 QinHeng Electronics
idProduct 0x7523 HL-340 USB-Serial adapter
bcdDevice 2.64
iManufacturer 0
iProduct 2
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0027
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 98mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 2
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 1It works fine with Ubuntu, the relay can be switched on and of via echo:
# turn on
echo -e '\xA0\x01\x01\xA2' > /dev/ttyUSB0
# ^ ^ ^
# | | |
# | | +-- checksum
# | +------ on
# +---------- relay no. 1
#
#
# turn off
echo -e '\xA0\x01\x00\xA1' > /dev/ttyUSB0
# ^ ^ ^
# | | |
# | | +-- checksum
# | +------ off
# +---------- relay no. 1 Or start
picocom -b 9600 -r -l /dev/ttyUSB0and press [CTRL]+A [CTRL]+W
*** hex: A00101A2
press [ENTER]
*** wrote 4 bytes ***
See the files in the conf.usbtty.prod directory. You may need to run the scripts as root, add sudo to run the echo command as root or add an extra udev rule to use the device as a unprivileged user.
Well, this is the escalation of overengineering. You could basically use the app that controls the Shelly device and wouldn't need this project here at all.
Or you could use your browser to connect to the wallbox web service that starts a script that calls the REST API of the Shelly device.
And that's excactly what I am doing at home. Because the Shelly app that must be used is way too slow. With the web service I have already switched that relay before that app has even started. And it can be used from any browser available at home.
It does not use SSL/TLS - meh. Probably I am going to shield it with a firewall in a distinct wifi and vlan.
I do not provide any information to wire the relais and/or the wallbox. Consult a professional electrician, we are talking about 400V here!
Since the web service is running via HTTPS in my home network, basic auth should be enough. If someone breaches into my network, I've got bigger problems than the possible usage of my wallbox.
Of course I do not use secret as a password ;-)
Well, after the decission to use the Shelly relay, it doesn't count anymore. The mobile browsers like Chrome and Firefox didn't want to store the credentials, so I commented the respective lines out. Maybe I come back to that later in time.
For development a self signed certificate is included, in production I use a certificate from my home CA that is set to be trusted in my browsers. On Android devices the Google Chrome and Firefox mobile browser seem to be very picky about certficates even if my home CA certificate is imported in the Android trust store. Therefore I use the monocles browser which is also picky but can pin the used certificate so that I don't need to fiddle around with those misleading security dialogs. The certificate is accepted by a bunch of different browsers on different operating systems. So the root of the problem is probably somewhere in the alphabet soup a.k.a. Android.
mkdir conf.dev && cd conf.dev
openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:4096 -keyout wb-selfsigned.key -out wb-selfsigned-cert.pem
Generating a RSA private key
(...)
Country Name (2 letter code) [AU]:DE
State or Province Name (full name) [Some-State]:NRW
Locality Name (eg, city) []:lab
Organization Name (eg, company) [Internet Widgits Pty Ltd]:acme.local
Organizational Unit Name (eg, section) []:org
Common Name (e.g. server FQDN or YOUR name) []:acme.local
Email Address []:[email protected]The "API" consists of only two methods and the responses are expected to be provided by the external commands that are used to set and query the relay state.
-
GET
/get/relay_stateAn external command gets called, see
get_relay_state_commandin the JSON configuration file.Response body
{"state":"on"}or
{"state":"off"}if you are unlucky
{"state":"unknown"} -
GET
/set/relay_state/{new_state}valid values for
{new_state}:onoff
An external command gets called, see
set_relay_state_commandin the JSON configuration file.{new_state}is passed as only argument.The external command is expected to set the relay state, wait for execution and query the new state.
Response body
{"state":"on"}or
{"state":"off"}If you are unlucky
{"state":"unknown"}
The MIT License (MIT)
Copyright © 2021 by Sven Putze (https://github.com/hardcodes/)
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
The license is also included as LICENSE-MIT file and applies only to my own code and/or contributions!
-
The icon was inspired by Wikipedia
-
The css code for the rocker switch was taken from
https://codemyui.com/checkbox-designed-as-rocker-switch-in-pure-css/
Copyright (c) 2021 by Marcus Connor (https://codepen.io/marcusconnor/pen/QJNvMa)
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
