IMPORTANT NOTICE: I will abandon this project because of the bad design regarding the RFM69 module and its antenna - I had not so good results because of that and due to space constraints. I'm switching again to nfr24l01(the NRF51822 RF SOC actually) to see if it performs better in this case. If it works as desired then I'll publish the new project on openhardware.io. Thanks for understanding.
Please bear in mind that I'm not responsible if the Livolo manufacturer will change the board hardware revision on which this project relies!!! This project works with this Livolo board hw revision only: VL-C700X-1 Ver: B8
Description:
This is a Mysensors replica of the Livolo EU Switch(2 channels 1 way) front plate.
Key Features:
Work progress:
Regarding point 1. from above: the EU variant that I have(VL-C700X-1 Ver: B8) doesn't expose the 12V line unfortunately. So I see 2 options here:
One another thing that I noticed is that the relays are bistable so I modified the schematic/pcb to accommodate that(the relays used on my livolo switch are: HFE60 12-1HST-L2 - 2 coils latching, 1 Form A as per datasheet).
Instructions:
This Livolo switch needs to be bought first(VL-C702 series)
Power/relays board needs some modifications as seen down below:
a) green marking no. 1 represents the 12-14V line wire connected to the power connector
b) green marking no. 2 represents the old 3V line trace cut from the power connector
a) green marking no. 1 represents the 12-14V line wire connected to the power connector
b) green marking no. 2 represents the modification needed for the resistor divider that drives the MOSFET
c) green marking no. 3 represents the big resistor(marked as 104) removed and replaced with a solder bridge
Need to adjust touch sensor capacitors for touch sensitivity if needed(caps marked with 0-50pF* on the board) - *I used 2pf capacitors**
Need to adjust LEDs series resistors regarding brightness(resistors marked with 1K* on the board) - *I used 5K1 resistors**
Burn MCU fuses using avrdude like this: avrdude -cusbasp -pm328p -U lfuse:w:0xe2:m -U hfuse:w:0xda:m
(for internal 8MHz RC oscillator and bootloader)
Burn DualOptiboot bootloader
Upload the provided sketch with this project or roll your own(pay attention to set this preprocessor define: #define MY_OTA_FIRMWARE_FEATURE
)
The provided sketch accepts on V_VAR1 this message format(with a limit of 25 characters) < node_name >:< sensor1_name >:< sensor2_name > - what this does is it will store those values in EEPROM and assign them to the node. Basically you get a node with named sensors instead of just displaying the numeric ids.
Very important:
Oh and please don't touch directly with your finger the sensor plates - use the plastics from the original board. I'm not responsible if you get an electric shock. 2. I noticed that the board is more stable if using good tantalum capacitors in the last power stage(on MIC5205 output) and for the radio module(10uf is enough - R type or 0805 metric which work on the 0603 hand soldering footprint too as it has longer pads - tested this myself) 3. As the space available is pretty limited a Helical antenna design can be used
HW Revisions:
Credits:
All credits go to MySensors team for the great work and to the opensource community