fvdpol / cve_controller

Controller for Itho CVE

CVE_Controller

Controller for the Itho CVE unit

Current Status: work in progress

Todo: - turn unit in stand-alone device - wireless communication via ESP8266 - ESP-Link

Done: - contruction of case/hardware - command parser - heartbeat - watchdog (including bootloader upgrade) - control of 7-segment display - read temperature moisture from SI7020 sensor - readout of input switch - control of relay - state machine - mains wiring

Frank van de Pol, 2016

Objective: Remote control & monitoring of the CVE Unit

Itho ECO CVE supports a wireless remote control over 868 MHz. Some hacks exist using reverse engineering of the protocol and using a CC1150 tranceiver to communicate with the CVE (http://www.progz.nl/blog/index.php/2014/12/reverse-engineering-remote-itho-cve-eco-rft-part-1/), or by modifying a remote unit and simulating button presses.

Drawback of above approach is that the solution is very specific to the Itho CVE Hardware, and even more important: it does not provide feedback on the current state (eg. local/other control switches).

Solution is a more generic approach using the classic perilex connector to control the unit.

Advantages:

• works with many brands of CVE (eg. Itho, Stork Air, Orcon, Zehnder, Vent-Axia)

  • connection to CVE using standard Perilex connector
  • fail-safe mode --> fan running slowly (depending on relais configuration)
  • speed control via remote switch (traditional fan speed switch in kitchen) commands over serial (usb) bus automatic switching basis the Humidity sensor values

• humidity control: SP hi,

• read-out/monitoring of state, measurements (temperature, humidity)

note: input protection for inputs (switch read-out) for systems with 220v switch (ie. standard wiring for CVE) an 220V relay may be used

    ?? use an optoisolator with capacitive supply (X2 series capacitor, resistor, rev.pol diode; rc filter)
    http://www.marcspages.co.uk/tech/6103.htm

    advantage of 220V switch: standard configuration; in case of problems/changes the controller can be removed 
    and the CVE connected to the Perilex socket that is controlled by the standard switch.

gebruik "HA framework" (zonder RF12)
github SI7021 library github arduino stuff: aparte repo per library/project (check: werkt dit met meerdere computers en sharing over seafile?)

watchdog: blink the dot on the 7-segment display

State Machine

Initial: --> State 1

State 0: Command Transition to 1 --> State 1 Command Transition to 2 --> State 2 Command Transition to 3 --> State 3 Switch Change to 1 --> State 1 Switch Change to 2 --> State 2 Switch Change to 3 --> State 3 Humidiy > SPhi --> store control state as 3; go to State H

State 1: Command Transition to 0 --> State 0 Command Transition to 2 --> State 2 Command Transition to 3 --> State 3 Switch Change to 2 --> State 2 Switch Change to 3 --> State 3 Humidiy > SPhi --> store control state as 3; go to State H

State 2: Command Transition to 0 --> State 0 Command Transition to 1 --> State 1 Command Transition to 3 --> State 3 Switch Change to 1 --> State 1 Switch Change to 3 --> State 3 Humidiy > SPhi --> store control state as 3; go to State H

State 3: Command Transition to 0 --> State 0 Command Transition to 1 --> State 1 Command Transition to 2 --> State 2 Switch Change to 1 --> State 1 Switch Change to 2 --> State 2 Humidiy > SPhi --> store control state as 3; go to State H

State H: Command Transition to 0 --> State 0 Command Transition to 1 --> State 1 Command Transition to 2 --> State 2 Command Transition to 3 --> State 3 Switch Change to 1 --> State 1 Switch Change to 2 --> State 2 Switch Change to 3 --> State 3 Humidiy < SPlo --> go to control State

simplification;

• Command Transition is always respected; go to requested state
• Input switch needs to detect changes (take into account delay/debounce); go to requested state
• Humidity > SPhi; store control state & transition to H state
• Humidity < SPlo; return to control state

enforce SPhi > SPlo

• store SP in EEProm
• at initialisation, read switch and use to transition

Hardware

Arduino Mini Pro 5v

Set Arduino IDE to: Board: Arduino Pro or Pro Mini Processor: ATMega 328 (5V, 16 MHz)

4-relay board (with opto isolators)

7 segment display (Kingbright SA52-11HWA, common anode)

LED Display:

0 - fan switched off 1 - fan in low speed 2 - fan in medium speed 3 - fan in high speed

H - High Humidity -> setpoint override

Kingbright SA52-11 HWA Pinout

 10   9   8   7   6
  |   |   |   |   |

         __a__
       f/    /b
       /__g_/ 
     e/    /c
     /____/  x
       d     dp

  |   |   |   |   |
  1   2   3   4   5

Pin	Function
1	e
2	d
3	CA
4	c
5	dp
6	b
7	a
8	CA
9	f
10	g

SI7021 I2C Humidity sensor for exhaust air monitoring

220V Relay for input monitoring

Coil with 220V; contact switch input on Arduino

Relay output switching

Configuration is set to make the default (controller unpowered) state is CVE running at speed #1

RE1	RE2	RE3	State
0	0	x	speed 1
0	1	0	speed 2
0	1	1	speed 3
1	x	x	speed 0

#Arduino I/O Assignment

Pin	Function
A4	I2C SDA
A5	I2C SCL
A0	Input A (manual selection Speed=2)
A1	Input B (manual selection Speed=3)
D2	Output Relay 1
D3	Output Relay 2
D4	Output Relay 3
D5	Output Relay 4 (tbd)
D6	Output 7 segment display a
D7	Output 7 segment display b
D8	Output 7 segment display c
D9	Output 7 segment display d
D10	Output 7 segment display e
D11	Output 7 segment display f
D12	Output 7 segment display g
D13	Output 7 segment display dp + onboard LED Arduino

| | A2 | Unassigned | A3 | Unassigned | A6 | Unassigned | A7 | Unassigned

Issue: Watchdog is nog working; when the watchdog gets activated the Arduino Pro hangs instead of performing a reboot

https://andreasrohner.at/posts/Electronics/How-to-make-the-Watchdog-Timer-work-on-an-Arduino-Pro-Mini-by-replacing-the-bootloader/

https://www.arduino.cc/en/Tutorial/ArduinoISP pins for ISP programming of new bootloader

ISCP Connector

Pin	ISP connector	ISP Programmer
1	MISO	D12
2	VCC	5V
3	SCK	D13
4	MOSI	D11
5	/RESET	D10
6	GND	GND

As the Arduino Pro Mini has a 6-pin ISP connector the programming was simply done by using ArduinoISP on an Uno Connections from Uno (programmer) to the Pro Mini (target) using 6 pin to 6 pin connector, with the exception of the reset line: pin 10 to pin 5 on the target's isp connector. To prevent the Uno auto-reset a 10uF capacitor was installed between Uno's reset pin and ground.

SI7021 Library

https://github.com/mlsorensen/SI7021

http://www.silabs.com/products/sensors/humidity-sensors/Pages/si7013-20-21.aspx

Sensor Features

• Precision Relative Humidity Sensor: ± 4% RH (maximum) @ 0–80% RH
• Temperature Sensor: ±0.4 °C accuracy (maximum) @ -10 to +85 °C
• 0 to 100% RH operating range
• Up to -40 to +125 °C operating range
• I2C host interface
• Integrated on-chip heater
• Tiny DFN package 3 mm x 3 mm
• Excellent long term stability
• Factory calibrated
• Optional factory-installed filter/cover
• Lifetime protection during reflow and in operation
• Protects against contamination from dust, dirt, household chemicals and other liquids
• AEC-Q100 automotive qualified (Si7013/20/21/34)

Pinout:

Pin	Function	Wire Color
1	VIN	Red
2	GND	Blue (+shield)
3	SCL	White
4	SDA	Yellow

Extension with ESP-Link

https://github.com/jeelabs/esp-link

NodeMCU "LoLin" Board as hardware

wifi mac address: 5c:cf:7f:0a:18:a4 Software: esp-link 2.2.3