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Table of Contents
ESP8266 Node
Wi-Fi enabled endpoint device based on ESP8266 microcontroller. It has modular design capable of connecting many different sensors or other electronics.
Specificatons:
| Microcontroller | ESP8266 |
|---|---|
| Operating voltage | 3.3 V |
| Input voltage | 4.5 - 12 V |
| Power consumption | ??? |
| Input voltage terminal | 5.5 mm center positive jack |
| Board dimensions | 45.72 x 45.72 mm |
| Sensor connection | 1x RJ-11 socket |
| User interface | Notification LED |
List of available sensors
RJ-11 pinout
| Pin | Connection |
|---|---|
| 1 | RXD |
| 2 | GND |
| 3 | GPIO2 |
| 4 | GPIO14 |
| 5 | VCC |
| 6 | TXD |
RJ-11 socket is connected to two GPIO pins, 3.3 V and GND. Pins 1 and 6 are used for debugging purposes. Its recommended to use 6P4C plug to connect sensors.
Electronics
Note: This is picture of v0.1.0 PCB version. Current version looks differently.
Features
- ISP header for convenient programming. See programmer below.
- PWR jumper is used to break connection between DC-DC converter and rest of the components. It is useful to allow user to adjust correct output voltage on the module.
- Tactile button is used to enter ESP8266 into programming mode without using DTR and RST pins on the ISP header.
- ISPPWR jumper allows user to select connection of ISP VTG pin and power branch of the board. User can select between VIN branch, 3V3 branch or disable connection entirely.
- Optional pull-up resistors for data lines can be soldered on the PCB (R5 and R6).
Buy PCB
You can buy PCB at Dirt Cheap PCB store.
Bill of materials
| Part | Pcs | Value | Package | Comment |
|---|---|---|---|---|
| ESP-12 | 1 | Or other ESP board with same pinout. | ||
| LM2596 DC-DC module | 1 | Power supply module. | ||
| 5.5 mm power jack | 1 | Power supply connector. | ||
| RJ-11 socket | 1 | Sensor socket. | ||
| Tactile button | 1 | 6 mm THT | ESP8266 programming mode. | |
| Electrolytic capacitor | 1 | 220 uF | E2,5-6 | |
| Ceramic capacitor | 1 | 100 nF | C0805 | |
| Resistor | 3 | 12K | R0805 | |
| Resistor | 1 | 470R | R0805 | |
| Resistor | 1 | 82R | R0805 | |
| Resistor | 2 | … | R0805 | Optional pull-up resistors. |
| NPN Transistor | 2 | SOT23-BEC | ||
| 2×3 Pin header | 1 | 2.54 mm | Programming header. | |
| 1×2 Pin header | 1 | 2.54 mm | Power supply enable jumper. | |
| 1×3 Pin header | 1 | 2.54 mm | Power supply select for programming header. | |
| LED | 1 | Red | 1206 | Notification LED. |
| Jumper | 2 | 2.54 mm |
Eagle files
3D printed case
You can get STL files at GitHub repository.
Power supply
Node can be powered any power supply with output voltage between 4.5 - 12 V. There are few tested solutions:
- 12V power supply for LED strips. Can be bought on eBay.
- USB phone charger with modified cable.
Firmware
Download source code:
$ git clone https://github.com/mqopen/esp8266-node
Configure source code tree:
$ cd esp8266-node esp8266-node$ make menuconfig
In menuconfig, configure device name, location, MQTT setting and select which sensor you'r using. Also configure correct pins in Bus Settings submenu.
Once you have firmware configured, compile it using following command:
esp8266-node$ make
Finally upload firmware into your hardware:
esp8266-node$ make upload
Programmer
For convenient programming of these devices you can build programmer. It has very similar header like AVR ISP, with proper modifications.
| Pin | AVR ISP | ESP8266 ISP |
|---|---|---|
| 1 | MOSI | TXD |
| 2 | VTG | VTG |
| 3 | GND | GND |
| 4 | GND | GND |
| 5 | RESET | RST |
| 6 | GND | GND |
| 7 | SCK | DTR |
| 8 | GND | GND |
| 9 | MISO | RXD |
| 10 | GND | GND |
Buy PCB
You can buy PCB at Dirt Cheap PCB store
Bill of materials
| Part | Pcs | Value | Package | Comment |
|---|---|---|---|---|
| FT232RL | 1 | SSOP28 | ||
| USB Mini SMD | 1 | USB-MINIB | ||
| LED | 1 | Blue | 0805 | Power LED. |
| LED | 1 | Green | 0805 | RX LED. |
| LED | 1 | Red | 0805 | TX LED. |
| Resistor | 2 | 1 K | 0805 | |
| Resistor | 2 | 330 R | 0805 | |
| Ceramic capacitor | 2 | 100 nF | 0805 | |
| Tantalum capacitor | 1 | 10 uF | 3216-18 | |
| 2×5 Pin header (box) | 1 | 2.54 mm | ISP header. | |
| 1×3 Pin header | 1 | 2.54 mm | PWR select jumper. |
devices/esp8266.txt · Last modified: 2016/06/15 09:11 by buben
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