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I have a Raspberry Pi Pico and I'm trying to get it Wifi Connected.

I'm using an ESP-01 with the sock firmware and confirmed AT commands are working through the Arduino serial monitor on both 115200 and 9600 Baud. To connect to my PC I am using an ESP-01S USB adapter I've gotten on amazon.

ESP-01S USB adapter

AT


OK
AT+GMR

AT version:1.2.0.0(Jul  1 2016 20:04:45)
SDK version:1.5.4.1(39cb9a32)
v1.0.0
Mar 11 2018 18:27:31
OK

          +--------------------------+
          | Both NL & CR | 9600 Baud |
          +--------------------------+

Once I get everything wired up to the Raspberry Pi Pico there is now a blue light on the ESP-01, which wasn't on with the USB serial adapter. And I do not get a response from the ESP-01.

+-------------------+                +-------------------+
|                   |      3.3v PS   |                   |
|   Raspberry Pi    |       = |      |      ESP-01       |
|      Pico         |       | +------+ 3.3v              |
|                   |       |        |                   |
|            GPIO 0 +----------------> RXD               |
|                   |       |        |                   |
|            GPIO 1 <----------------+ TXD               |
|                   |       |        |                   |
|               GND +-------+--------+ GND               |
|                   |                |                   |
|                   |                |                   |
+-------------------+                +-------------------+

from machine import UART
uart = UART(0, baudrate=9600)

def write(msg):
    print("Sending %s" % msg)
    uart.write(msg)

write('AT\r\n')

while True:
    if t:
        print(t)
    else:
        t = uart.readline()
        print('.', end="")

Tried with multiple baudrates as well as UART 0 and UART 1 (TX=0, RX=1 and TX=4, RX=5). ESP-01 is supplied with 3.3v and not using power from the Raspberry Pi.

What could be going on that would prevent a response?

Sean O'Rourke
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  • You said that the ESP-01 isn't getting 3.3V from the Pi. Where is it getting 3.3V from? Is GND from that source connected to GND on the ESP-01 and the Pico? – romkey Jun 29 '21 at 15:56
  • The ESP-01 has it's own power supply and they share a ground. Tried to update original post to reflect. – Sean O'Rourke Jun 29 '21 at 16:14
  • your esp-01 wiring is incomplete – Juraj Jun 29 '21 at 18:14
  • If you have an ESP-01 instead of ESP-01S, the ch_pd pin does not have an on-board resistor to pull it up to 3.3V. You need to add it yourself or directly tie it to 3.3V. – hcheung Jul 01 '21 at 01:59

0 Answers0