How to build the Hub B (stand-alone)
The Hub B provides the following functionalities:
- Infrared transmitter and receiver (ESP32 module 1)
- 433 Mhz (RC) transmitter and receiver (ESP32 module 2)
- Buck and Boost converter (Arduino / ATMega328P) with output voltages adjustable in the firmware
- Radio traffic LEDs
The hub must be powered with a 5V DC power supply through one of the following connectors:
- USB type C (J3)
- Micro USB (J1)
- 5.5 mm power Jack (J2)
The max current (A) of the power supply depends on the number and type of IR LED that you want to drive. For the setup described below in this wiki with 3 high power LEDs, a 3 Ampere power supply is sufficient.
Required Hardware
The list of all the components required for the assembly of a full d-diot hub is reported below, divided in categories for better readability.
All the electronic parts are available on the market in generic e-commerce platform (like ebay or amazon) or specialized electronic parts distributor, like LCSC, Digikey, Mouser, etc…
d-diot board 4B
The hub B is built with the d-diot board 4B.
Below the schematics ( pdf format).
You can order the board 4B directly from PCBWay.
ESP32 modules
Two ESP32 - 30 Pin module are required.
You can find it in generic stores for about 3-4€ (example here)
Arduino Nano / ATMega328P
Regarding the microcontroller, which provides the Boost and Buck converter functionalities for the FS1000A transmitter and IR led respectively, you have two choices, depending on your soldering skills and equipment.
Option 1: Arduino Nano board
A standard Arduino Nano board is available in generic e-commerce platforms for few euros.
It has an USB port, so it is easy to program and you don't have to solder the ATMega328 chip to the board. This is the perfect choice if you don't feel like a iron solder hero.
Option 2: ATMega328P
The MCU is available in generic e-commerce platforms for 1 - 2 euros.
Infrared (IR) receiver and transmitter
The TSOP4838 component is used as IR receiver, while 3 high power (3W) 940 nm IR LEDs with a star heatsink are used as IR transmitters.
433 Mhz transmitter and receiver
The FS1000A module is used as 433 Mhz transmitter, while the RXB6 module is used as 433 Mhz receiver.
A 433 Mhz helical antenna should be soldered on the FS1000A module, while for the RXB6 you can solder an 433 Mhz helical antenna in AE1, or alternatively you can connect an external male antenna to the optional J12 SMA connector.
Power switch
The case has a hole to host a power switch to completely cut off the power.
Any switch compatible with the dimensions reported in the picture above can be used without any modification. For example I have used one of this.
Spare parts
To complete the build you need the following parts:
- M2.5 self tapping screw
- Jumper caps
Electronic components
The list of all the electronics components required for assembly of the d-diot board 4B is reported below:
| References | Description | Value | Quantity | Vendor | Link | VPN | Manufacturer | MPN |
|---|---|---|---|---|---|---|---|---|
| C14 | Capacitor 10 uF SMD | 10uF | 1 | LCSC | view | C15850 | Samsung Electro-Mechanics | CL21A106KAYNNNE |
| C15 | Capacitor 0.47 uF SMD 0805 | 0.47uF | 1 | LCSC | view | C15972 | Samsung Electro-Mechanics | CL21B474KAFNNNE |
| C5- C6 | Capacitor 100 uF SMD | 100uF | 2 | LCSC | view | C97805 | ST(Semtech) | CS1C101M-CRE54 |
| C13 | Capacitor 220 uF SMD | 220uF | 1 | LCSC | view | C97815 | ST(Semtech) | CS1E221M-CRF10 |
| C12 | Capacitor 1000 uF SMD | 1000uF | 1 | LCSC | view | C280406 | ROQANG | RT1A102M0810 |
| C1- C2- C3- C4- C7- C10- C11- C16 | Capacitor 0.1 uF SMD 0805 | 0.1uF | 8 | LCSC | view | C38141 | FH(Guangdong Fenghua Advanced Tech) | 0805B104K500NT |
| C8- C9 | Capacitor 20 pF SMD 0805 | 20pF | 2 | LCSC | view | C105173 | YAGEO | CC0805JRNPO9BN200 |
| R5 | Resistor 3.3 KOhm SMD 0805 | 3.3K | 1 | LCSC | view | C445653 | PANASONIC | ERA6AEB332V |
| R2 | Resistor 100K SMD 0805 | 100K | 1 | LCSC | view | C57246 | UNI-ROYAL(Uniroyal Elec) | TC0525F1003T5E |
| R1- R6- R9- R10- R12 | Resistor 300 Ohm SMD 0805 | 300 | 5 | LCSC | view | C61685 | UNI-ROYAL(Uniroyal Elec) | TC0525F3000T5E |
| R3- R4- R7- R8- R11- R13 | Resistor 10K SMD 0805 | 10K | 6 | LCSC | view | C57859 | UNI-ROYAL(Uniroyal Elec) | TC0550F1002T5E |
| L2 | Inductor 100uH - 3.2A - SMD | 100uH-3.2A | 1 | LCSC | view | C429837 | TDG | TMAX-1365-101-M |
| L1 | Inductor 470uH - 500mA - SMD | 470uH-500mA | 1 | LCSC | view | C467161 | SXN(Shun Xiang Nuo Elec) | SMNR8040-471MT |
| D2- D3 | Schottky Barrier Diodes SMD SMA | SS54 | 2 | LCSC | view | C513478 | Slkor(SLKORMICRO Elec.) | SS54 |
| D1 | Blu Led SMD 0805 | B-LED | 1 | LCSC | view | C84259 | Foshan NationStar Optoelectronics | NCD0805B2 |
| D5- D6 | Green Led SMD 0805 | G-LED | 2 | LCSC | view | C84260 | Foshan NationStar Optoelectronics | NCD0805G1 |
| D4- D7 | Yellow Led SMD 0805 | Y-LED | 2 | LCSC | view | C84261 | Foshan NationStar Optoelectronics | NCD0805Y1 |
| U1 | ATmega328-AU microcontroller SMD | ATmega328P-AU | 1 | LCSC | view | C14877 | Microchip Tech | ATMEGA328P-AU |
| U2- U4 | ESP-WROOM-32 module 30 pin | ESP32_DevKit_V1_DOIT | 2 | zhenzhen-i | view | NA | NA | NA |
| U3 | IR receiver TSOP4838 5V | TSOP4838 | 1 | LCSC | view | C124647 | Vishay Intertech | TSOP4838 |
| Y1 | Crystal resonator 16 Mhz SMD-5032_2P | Crystal 16 Mhz | 1 | LCSC | view | C251590 | SJK(SHENZHEN CRYSTAL TECH) | 6I16000F20UCG |
| F1 | Resettable fuse SMD 1210 | Polyfuse | 1 | LCSC | view | C70190 | TECHFUSE | SL1210600 |
| SW1 | Push button SMD 3x6x2.5 mm | RESET | 1 | Alphago it | view | NA | NA | NA |
| A1 | Arduino Nano v.3.0 5V 16 Mhz | Arduino_Nano_v3.x | 1 | cayin35 | view | NA | NA | NA |
| Q1 | P channel mosfet THT TO-220-3 | FQP27P06 | 1 | LCSC | view | C462764 | ON Semiconductor | FQP27P06 |
| Q4- Q5- Q6- Q9 | N channel mosfet SMD SOT-23 | JST2300 | 4 | LCSC | view | C404846 | JESTEK | JST2300 |
| Q2- Q3- Q8 | P channel mosfet SMD SOT-23 | JST3415C | 3 | LCSC | view | C404849 | JESTEK | JST3415C |
| AE1 | 433 Mhz helical antenna | Antenna | 1 | adeleparts2010 | view | NA | NA | NA |
| RF1 | FS1000A connector - female pin header 1×03 p.2.54 | FS1000A | 1 | LCSC | view | C358717 | MINITRON | MTF185-103SY1 |
| JP2 | Male 2.54 mm pin header THT 1×03 | V-DATA | 1 | NA | NA | NA | NA | NA |
| J2 | 5.5 mm DC Power jack | Barrel_Jack | 1 | Mouser | view | 710-694106301002 | Wuerth | 694106301002 |
| J14 | 5.5 mm DC Power jack | IR-OUT-EXT | 1 | Mouser | view | 710-694106301002 | Wuerth | 694106301002 |
| J12 | Coaxial SMA antenna connector | ANT-EXT | 1 | LCSC | view | C411575 | Shenzhen Kinghelm Elec | KH-SMA-K513-G |
| J18 | USB type A female connector SMD | USB-A | 1 | LCSC | view | C8328 | Jing Extension of the Electronic Co. | YJ-USB-AF-SMT-01 |
| J6 | Male 2.54 mm pin header THT 2×03 | ICSP | 1 | LCSC | view | C65114 | BOOMELE(Boom Precision Elec) | C65114 |
| J7 | Male 2.54 mm pin header THT 1×06 | FTDI | 1 | LCSC | view | C190819 | nextron(Nextronics Engineering) | Z-211-0611-0021-001 |
| J11 | RXB6 connector - female pin header 1×04 p.2.54 - 2 units | RXB6 | 1 | LCSC | view | C225501 | CJT(Changjiang Connectors) | A2541HWV-4P |
| J1 | Micro USB port SMD | USB_B_Micro | 1 | LCSC | view | C10418 | Jing Extension of the Electronic Co. | C10418 |
| J4- J8- J9 | Screw terminal 2 pin p.5.08 | POW | 3 | LCSC | view | C474906 | Cixi Kefa Elec | KF127-5.08-2P |
| J5 | Screw terminal 2 pin p.5.08 | MAIN-SW | 1 | LCSC | view | C474906 | Cixi Kefa Elec | KF127-5.08-2P |
| J3 | USB type C port SMD | USB-C | 1 | fastener-kingdom | view | NA | NA | NA |
| J15- J16- J17 | Male 2.54 mm pin header THT 1×02 | IR-OUT | 3 | NA | NA | NA | NA | NA |
| J10- J13- J19- J20 | Pin header male 1×15 p.2.54 | Conn_01x15_Male | 4 | NA | NA | NA | NA | NA |
3d printable case
The 3d model files and the print instructions of the case are available in thingiverse.
If you don't have access to a 3d printer, you can consider an online 3d printing service.
Firmware upload
It is convenient to flash the firmware before installing the modules on the board.
Arduino Nano / ATMega328P
You can find the code as PlatformIO projects here.
The upload and library management with PlatformIO are easier respect to the standard Arduino IDE, so if you have Platformio you can follow this guide to upload the firmware.
If you have soldered the ATMega328P you need to flash it with the Optiboot Arduino Nano new bootloader (ICSP connector J6) and then you can upload the firmware with an FTDI adapter connected to the header J7. If you are using an Arduino Nano board most likely you already have the right bootloader.
See this guide to know how to burn a bootloader to an ATMega MCU.
ESP32 modules
The two ESP32 modules requires a firmware generated by ESPHome.
- The configuration yaml file for the module U2 (433 Mhz RC gateway) is here
- The configuration yaml file for the module U4 (IR gateway) is here
You can follow this guide to see how to install ESPHome and this one to see how to upload the firmware to your device.
Building instructions
Print the case
Well, this is the most time consuming part of the building, but once you have started the print job, you don't have too much to do except watching your 3d printer at work, so you can proceed with the other steps.
The model files are here.
You need to print the following models (file name):
- 1 x base.stl
- 1 x top-simple.stl
- 1 x board-4B-body-standalone.stl
- 1 x front-led-cover.stl
- 3 x ir-led-cover.stl
- 4 x supports.stl
Solder the components
Some components are THT, while some other are SMD, but generally with a package that is not so difficult to handle. See this to know what tools you need.
Use the interactive BOM tool to see where to place each component for the d-diot board 4B
This is how the board should looks with all the component soldered
Jumper Configuration
The typical jumper configuration is reported below. See the ( schematics) to know more about what each jumper does.
- JP1: Open, the two pad must not be bridged. Close the jumper if you want to bypass the main power switch.
- JP2: Bridge the GPIO and D pins with a jumper cap
Assembly and wiring
- Install the two ESP32 modules, the RXB6 and the FS1000A radio modules
- Fix the 4 supports to the base with 4 M2.5 screws, place the board into the base of the case and fix it with 4 M2.5 screws
- Install the three IR led covers and the front led covers to the board-4B-body-standalone part of the case and solder two pieces of wire to the main power switch.
- Solder two wires to the positive and negative poles of each IR LED, fix the three LEDs to the case with hot glue (or anything else) and install the main switch.
- Fix board-4B-body-standalone to the base with two M2.5 screws, connect the two wires of the main switch to the screw terminal J5 and connect the IR LEDs wires to the J15, J16 and J17 headers
- Fix the top-simple part of the case to the board-4B-body-standalone part with 2 M2.5 screws and, if you have soldered the optional J12 connector, install the antenna of the RXB6 radio module. Done!
Integration with Home Assistant
ESP32 - ESPHome
ESPHome is well integrated in Home Assistant (see here), so adding your device is easy and it explained here.
Below how the Hub B entities looks like in the Home Assistant WebUI
Usage
Connect a +5V DC power source to one of the following connectors:
- J2: barrel jack
- J1: micro USB
- J3: USB typoe C
Turn the main switch on and, if all is configured correctly, the entities of the ESP32 module (ESPHome firmware) should show up in Home Assistant.
Read this guide to know how to send an IR code with ESPHome and this one to know how to capture the IR code from your remote. In the ESP32-IR-GW configuration file in yaml format you have an example.
Read this guide to know how to send an RC code with ESPHome and this one to know how to capture the RC code from your remote. In the ESP32-RC-GW configuration file in yaml format you have an example.
In order to have more flexibility in the placement of the hub in your home:
- The J14 barrel jack offers the possibility to connect external IR LEDs, instead of using the integrated ones. The function of the J14 connector is the same of the headers J15, J16, J17
- The USB A port (J18) offers the possibility to connect an external and independent IR signal transmitter. See the schematics to know the pinout.