ESP8266 Community Forum

- Tue Jan 06, 2015 9:38 am #6461 I ordered and received 20 units of ESP-07 (newest version, with the ceramic chip antenna, external antenna connector, and shielded chips with FCC logo).

I am using a FT232RL to communicate with it. From what I understand some of these are shipping from manufacturers (via AliExpress, eBay, etc) with absolutely nothing on them.

So to enter flash mode I did the following (obtained information from an ElectroDragon link for a similar ESP-??):
3.3v VCC <--> VCC
3.3v VCC <--> 10K pull-up resistor <--> CH_PD, also works if you do just 3.3v VCC <--> CH_PD (some sites and diagrams suggest the use of a pull-up resistor instead of a direct connection, even the adapter boards that are showing up have pads for SMD resistors to bridge 3.3v VCC and CH_PD as well pull-down resistor pads for GND to GPI0 for flash mode. See http://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20150106063253&SearchText=esp8266+adapter)
GND <--> GND
GND <--> GPIO15
GND <--> GPIO0
TX <--> RXD
RX <--> TXD

The ESP-07 I believe has the same pin-out as the ESP-12 (sanity check: https://scargill.wordpress.com/2015/01/03/esp-12-in-practice/).

Using this Windows Development Environment:
http://www.esp8266.com/viewtopic.php?f=9&t=820&sid=7

I flashed:
at_v0.20_on_SDKv0.9.4

It was a bit difficult to get this ESP-07 into flash mode. I was able to flash it successfully a few times, the times in between it would fail to flash, I thought it might be that my serial leads were too long or there was interference somehow. I shortened the TX and RX jumper lead to barely nubs connecting to the FTDI232RL board. When I did get it to go through the whole process, it flashed both locations 0x00000 to 100% and 0x40000 to 100% and then the message "leaving" or done, etc.. whatever the success message was for leaving flash mode.

Disconnected VCC to the ESP-07, removed GPIO0 from GND, put ESP-07 VCC back to 3.3v VCC to power up in normal mode being the following:

3.3v VCC <--> VCC
3.3v VCC <--> 10K pull-up resistor <--> CH_PD, also works if you do just 3.3v VCC <--> CH_PD (some sites and diagrams suggest the use of a pull-up resistor instead of a direct connection, even the adapter boards that are showing up have pads for SMD resistors to bridge 3.3v VCC and CH_PD as well pull-down resistor pads for GND to GPI0 for flash mode. See http://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20150106063253&SearchText=esp8266+adapter)
GND <--> GND
GND <--> GPIO15
TX <--> RXD
RX <--> TXD

I tried using PeteSerial (https://scargill.wordpress.com/2014/12/12/the-simple-serial-terminal-revisited/) and Putty at all different speeds to attempt to communicate with the ESP-07 and all that I can see is the RX led blink on the FT232RL, the ESP-07 just sits there with the blue power LED lit and no other activity at all. I have even tried several different FT232RL adapters with the same exact results.

Does anyone know what I am doing wrong here?

- Tue Jan 06, 2015 5:46 pm #6498

and all that I can see is the RX led blink on the FT232RL, the ESP-07 just sits there with the blue power LED lit and no other activity at all. I have even tried several different FT232RL adapters with the same exact results.

Does anyone know what I am doing wrong here?

Not really, I don't see any mistakes, you seems to be well informed on the use of the ESP, and you have already flashed new firmware, so basically it seems OK.

I have an ESP-01 running, and today I got an ESP-07 (from Banggood) "in". I just started connecting it.

Maybe my fresh experience helps, maybe not:
- On my ESP-7 from Banggood the Power LED is RED (not BLUE), it lights up when the power lines are connected (duh!)
- When powered on, and you then connect CH-PD to Vcc, the BLUE LED flashes shortly. On the ESP-01 the Blue led is connected to the ESP-TX line. It flashes because the bootloader is sending serial output on the ESP-TX line, guess it's the same for the ESP-07.
- If you don't see the BLUE LED flashing with these 3 connections, I guess you're in real trouble.

If the BLUE led flashes, I would:
- check your power source. I have used the 3.3V line from an FT232. Initially that seemed to work OK, but later I have experienced unreliable reset behaviour, firmware uploads, etc. When I switched to 2 AA batteries in series all troubles were gone..
- check that RX and TX on the USB-serial adapter is what you expect it to be. Often the TX and RX on usb-serial are labeled in reverse. If the adapter has LEDs on the TX and RX line, the LED on the receiving line should flash similar as the Blue LED on the ESP
- there should be some "gibberish" in your terminal from the ESP bootloader, its serial data with a weird baudrate. If you don't get this data in you terminal, either your connections are wrong, or the firmware on the ESP does not send bootloader to the serial port.
- check that your serial terminal is set for CR/LF

That's all the help I can give you right now, now returning to further connecting my own ESP-07. Nice board!!

Let us know if you have any progress.

Last edited by gerardwr on Tue Jan 06, 2015 5:58 pm, edited 2 times in total.

- Tue Jan 06, 2015 5:47 pm #6499

and all that I can see is the RX led blink on the FT232RL, the ESP-07 just sits there with the blue power LED lit and no other activity at all. I have even tried several different FT232RL adapters with the same exact results.

Does anyone know what I am doing wrong here?

Not really, I don't see any mistakes, you seem to be well informed on the use of the ESP, and you have already flashed new firmware, so basically it seems OK.

I have an ESP-01 running, and today I got an ESP-07 (from Banggood) "in". I just started connecting it.

Maybe my fresh ESP-07 experience helps, maybe not:
- On my ESP-7 (from Banggood) the Power LED is RED (not BLUE), it lights up when the power lines are connected (duh!)
- When powered on, and you then connect CH-PD to Vcc, the BLUE LED flashes shortly. On the ESP-01 the Blue led is connected to the ESP-TX line. It flashes because the bootloader is sending serial output on the ESP-TX line, guess it's the same for the ESP-07.
- If you don't see the BLUE LED flashing with these 3 connections, I guess you're in real trouble.

If the BLUE led flashes, I would:
1 - check that RX and TX on the USB-serial adapter is what you expect it to be. Often the TX and RX on usb-serial are labeled in reverse. If the adapter has LEDs on the TX and RX line, the LED on the receiving line should flash similar as the Blue LED on the ESP
2 - there should be some "gibberish" in your terminal from the ESP bootloader, its serial data with a weird baud rate. My ESP-07 sends this "gibberish" to the serial terminal. If you don't get this data in you terminal, either your connections are wrong, or the firmware on the ESP does not send bootloader to the serial port.
3 - After the "Gibberish" you should get "ready" when a proper AT firmware is flashed.
4 - Enter an AT command, the ESP hold respond with an OK. If that does not work, check that your serial terminal is set for CR/LF.

That's all the help I can give you right now, now returning to further connecting my own ESP-07. Nice board!!

- Wed Jan 07, 2015 6:00 am #6530 The ESP-03 requires GPIO15 to be connected (or pulled down) to GND, aside from the standard CH_PD to +3V3. Maybe the ESP-07 requires the same? I don't have the 07 yet unfortunately.

EDIT: I see now you already tried that, never mind.

I'm still having doubts whether to order ESP-07's with the ceramic antenna, or ESP-12's with the onboard PCB one.. Any recommendations so far? GeoNomad already explained that ceramic outperforms PCB with nearby metal or hands etc, and PCB has better gain, but I'm not sure what the implications of using either are outside of that.