esp8266_gpio_pin_allocations
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esp8266_gpio_pin_allocations [2017/10/30 08:09] dampmaskin [PWM] correction |
esp8266_gpio_pin_allocations [2017/11/10 02:18] ekriirke [Pin Functions] |
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| ^FLASH (NormalRunning) | 0 | 1 | x or 1 | \\ | ^FLASH (NormalRunning) | 0 | 1 | x or 1 | \\ | ||
| - | __Note__ :- GPIO2 It is considered safer to pull it high with a resistor on boot rather than leave it floating to avoid possible chip damage if pin is pulled high by your program but also see [[http://www.esp8266.com/viewtopic.php?f=6&t=3862&p=22524#p22524|http://www.esp8266.com/viewtopic.php?f=6&t=3862&p=22524#p22524]]. | + | __Notes__ :- GPIO2 It is considered safer to pull it high with a resistor on boot rather than leave it floating to avoid possible chip damage if pin is pulled high by your program but also see [[http://www.esp8266.com/viewtopic.php?f=6&t=3862&p=22524#p22524|http://www.esp8266.com/viewtopic.php?f=6&t=3862&p=22524#p22524]]. GPIO1 (UART TX) also has an effect on boot if pulled low; it will not boot in this case. |
| FLASH mode is when running the program. Take GPIO0 high or float or it will stall on first reset, intentional or not. | FLASH mode is when running the program. Take GPIO0 high or float or it will stall on first reset, intentional or not. | ||
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| ===== LED Pin ===== | ===== LED Pin ===== | ||
| - | GPIO1, which is also TX, is wired to the blue LED on many devices. Note that the LED is active low (connected to Vcc and sinks through the chip to ground) so setting a logical value of 0 will light it up. Since GPIO1 is also the TX pin, you won't be able to blink the LED and perform Serial communications at thew same time unless you switch TX/RX pins. | + | GPIO1, which is also TX, is wired to the blue LED on many devices. Note that the LED is active low (connected to Vcc and sinks through the chip to ground) so setting a logical value of 0 will light it up. Since GPIO1 is also the TX pin, you won't be able to blink the LED and perform Serial communications at the same time unless you switch TX/RX pins. |
| + | Note that if this pin is pulled LOW on power up, the ESP will not boot. (The normal LED is from Vcc to IO1, an LED from GND to IO1 is enough to prevent boot) | ||
| ===== Maximum Current ===== | ===== Maximum Current ===== | ||
esp8266_gpio_pin_allocations.txt · Last modified: 2017/11/10 02:18 by ekriirke