6.0 KiB
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Supported Hardware |
- Adafruit HUZZAH ESP8266 (ESP-12)
- NodeMCU 0.9
- NodeMCU 1.0
- Olimex MOD-WIFI-ESP8266-DEV
- Olimex MOD-WIFI-ESP8266
- SparkFun ESP8266 Thing
- SweetPea ESP-210
- Generic ESP8266 modules
Adafruit HUZZAH ESP8266 (ESP-12)
TODO: add notes
NodeMCU 0.9
Pin mapping
Pin numbers written on the board itself do not correspond to ESP8266 GPIO pin numbers. Constants are defined to make using this board easier:
static const uint8_t D0 = 16;
static const uint8_t D1 = 5;
static const uint8_t D2 = 4;
static const uint8_t D3 = 0;
static const uint8_t D4 = 2;
static const uint8_t D5 = 14;
static const uint8_t D6 = 12;
static const uint8_t D7 = 13;
static const uint8_t D8 = 15;
static const uint8_t D9 = 3;
static const uint8_t D10 = 1;
If you want to use NodeMCU pin 5, use D5 for pin number, and it will be translated to 'real' GPIO pin 14.
NodeMCU 1.0
TODO: add notes
Olimex MOD-WIFI-ESP8266-DEV
This board comes with 2 MB of SPI flash and optional accessories (e.g. evaluation board ESP8266-EVB or BAT-BOX for batteries).
The basic module has three solder jumpers that allow you to switch the operating mode between SDIO, UART and FLASH.
The board is shipped for FLASH operation mode, with jumpers TD0JP=0, IO0JP=1, IO2JP=1.
Since jumper IO0JP is tied to GPIO0, which is PIN 21, you'll have to ground it before programming with a USB to serial adapter and reset the board by power cycling it.
UART pins for programming and serial I/O are GPIO1 (TXD, pin 3) and GPIO3 (RXD, pin 4).
Get the board schematics here
Olimex MOD-WIFI-ESP8266
This is a stripped down version of the above. Behaves identically in terms of jumpers but has less pins readily available for I/O. Still 2 MB of SPI flash.
SparkFun ESP8266 Thing
Product page: https://www.sparkfun.com/products/13231
TODO: add notes
SweetPea ESP-210
TODO: add notes
Generic ESP8266 modules
These modules come in different form factors and pinouts. See the page at ESP8266 community wiki for more info: ESP8266 Module Family.
Usually these modules have no bootstapping resistors on board, insufficient decoupling capacitors, no voltage regulator, no reset circuit, and no USB-serial adapter. This makes using them somewhat tricky, compared to development boards which add these features.
In order to use these modules, make sure to observe the following:
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Provide sufficient power to the module. For stable use of the ESP8266 a power supply with 3.3V and >= 250mA is required. Using the power available from USB to Serial adapter is not recommended, these adapters typically do not supply enough current to run ESP8266 reliably in every situation. An external supply or regulator along with filtering capacitors is preferred.
-
Connect bootstapping resistors to GPIO0, GPIO2, GPIO15 according to the schematics below.
-
Put ESP8266 into bootloader mode before uploading code.
Serial Adapter
There are many different USB to Serial adapters / boards.
- Note
- for full upload management you need RTS and DTR
- the chip need to have 3.3V TTL (5V may damage the chip)
- not all board have all pins of the ICs as breakout (check before order)
- CTS and DSR are not useful for upload (they are Inputs)
- Working ICs
- FT232RL
- CP2102
- CH340G
- maybe others (drop a comment)
Minimal Hardware Setup for Bootloading and Usage
ESPxx Hardware
PIN | Resistor | Serial Adapter |
---|---|---|
VCC | VCC (3.3V) | |
GND | GND | |
TX or GPIO2* | RX | |
RX | TX | |
GPIO0 | PullUp | DTR |
Reset* | PullUp | RTS |
GPIO15* | PullDown | |
CH_PD | PullUp |
- Note
- GPIO15 is also named MTDO
- Reset is also named RSBT or REST (adding PullUp improves the stability of the Module)
- GPIO2 is alternative TX for the boot loader mode
- Directly connecting a pin to VCC or GND is not a substitute for a PullUp or PullDown resistor, doing this can break upload management and the serial console, instability has also been noted in some cases.
ESP to Serial
Minimal Hardware Setup for Bootloading only
ESPxx Hardware
PIN | Resistor | Serial Adapter |
---|---|---|
VCC | VCC (3.3V) | |
GND | GND | |
TX or GPIO2 | RX | |
RX | TX | |
GPIO0 | GND | |
Reset | RTS* | |
GPIO15 | PullDown | |
CH_PD | PullUp |
- Note
- if no RTS is used a manual power toggle is needed
Minimal Hardware Setup for Running only
ESPxx Hardware
PIN | Resistor | Power supply |
---|---|---|
VCC | VCC (3.3V) | |
GND | GND | |
GPIO0 | PullUp | |
GPIO15 | PullDown | |
CH_PD | PullUp |