ESP8266 Community Forum

- Thu Dec 11, 2014 9:47 am #4559

GPIO15 must be pulled down to GND, that's the only requirement. It is possible your module didn't come with firmware loaded into it. To flash it, you need to pull GPIO0 down and do a reset, it'll go into the bootloader. The tricky part is the reset isn't broken out, you need to solder a wire to a spare goldepin from a not installed resistor near the red wire. It is mentioned in another topic.

I did start to think that perhaps my module did need firmware flashing, and I also read the thread about the XPD_DCDC pin connecting to GPIO16 and optionally to RST. I was left a little unsure of the implications - although I definitely also need to go into a very low power mode so that I can make periodic wake-ups, send sensor data and then carry on saving battery life.

I'll post a question in that other thread about the implications of making the solder bridge to bring reset to GPIO16.

Thanks for the info anyway!

Gareth

- Thu Dec 11, 2014 9:52 am #4560

Did you not forget to connect GND of the module to GND or your rPI? Otherwise the two will be only AC coupled.

I've made that mistake in the past, and I'm dedicated to making new mistakes now, so I made sure I joined the ground together so they would share a reference.

And do you use a proper 3.3V power supply? I don't think the PI can power the module.

Yes, I am using an ATX psu together with the Dangerous Prototypes board - it can supply a huge amount of current - 14A!! so that's unlikely to be the problem!!

Connect GPIO0 and GPIO15 to GND, CH_PD to VCC before powering up the module.
Then launch esptool to flash a .bin file.

That's interesting - so I can bring it into firmware update mode from power down and don't need to wiggle the reset pin?

Can you confirm this esptool command looks ok?

Code: Select all./esptool.py --port /dev/ttyAMA0 write_flash 0x000000 0922.bin

Many thanks for your help

Gareth

- Thu Dec 11, 2014 10:41 am #4565

I've been playing with my new ESP-03's from electrodragon for a couple of days and I am tearing my hair out!

I've tried every baud rate and still can't get anything on a terminal that isn't rubbish!!

My trusty USB bub II thingy blew the other week so I'm using a raspberry pi to connect to the UART interface.

To invoke a terminal on the pi I first edited /etc/inittab to disable the serial console, then use:

Code: Select allpicocom /dev/ttyAMA0 -b 9600

All I get at any baud rate is gibberish with occasional control characters that clear the screen etc!!

I also tried to upload new firmware, also without success.

I've checked for soldering problems and tried most combinations of GPIO's to VCC/GND I can think of.

20141209_160943.jpg

(photo shows my setup but don't worry about the connections shown - I tried all the versions listed in this thread and many more!)

Any bright ideas?

Thanks in advance

Gareth

Just you know, serial input on the esp only can handle 3.3 logic. I used zener diod in parallel with gnd and a resister in series with tx line on your serial output of what ever you using. This make sure, line stays at 3.3v.

Second thing is atleast you should get some gibberish on the terminal, if do try putting one of the newer firmware to it by runing gpio0 to the ground.

- Thu Dec 11, 2014 10:59 am #4570

Connect GPIO0 and GPIO15 to GND, CH_PD to VCC before powering up the module.
Then launch esptool to flash a .bin file.

That's interesting - so I can bring it into firmware update mode from power down and don't need to wiggle the reset pin?

Exactly, that's what I do.

Can you confirm this esptool command looks ok?

Code: Select all./esptool.py --port /dev/ttyAMA0 write_flash 0x000000 0922.bin

Looks fine. If all goes well you should see it's writing to flash, and this means your serial connection is working at least.