ESP8266 Community Forum

- Wed Nov 29, 2017 11:21 am #72166 hi folks i have a mysterious problem

i have a esp8266-12e on NodeMCU module... i've made a script with arduino IDE to control a bipolar stepper motor through a Easy driver (this https://learn.sparkfun.com/tutorials/ea ... k-up-guide)

Both easy driver and esp are connected to 8VDC ...
when i plug the power ... the easydriver card turn on but esp stay frozen... if i push the reset button then everything boot and works good.

this is the pin i am using:

#define stp 16
#define dir 5
#define MS1 4
#define MS2 0
#define EN 2
#define bot_stop 14
#define bot_velo 12
#define buzz 13

but i tried to disconnect some of the pin but the trouble persists.
If i power the esp through the usb port it works and boot easily.


the strange part is that i tried to monitor the device through a FT232 and my computer... the ESP didnt froze anymore... and the result is this one at boot:

ets Jan 8 2013,rst cause:2, boot mode:(3,1)

load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
v09f0c112
~ld


i hope someone can help me with this

- Wed Nov 29, 2017 2:05 pm #72169 What pull up resistor do you have on the reset line? Do you also have a capacitor to ground, and if so then what value is the capacitor?

Your problems are most likely not a port or code problem. Most likely a power supply issue, but there needs to be more information to determine that. Use a 10K-47K pull up resistor. Try and use a higher value if you have it. For a capacitor to ground use at least a 0.47uF capacitor, this can go up to 10uF. I prefer to keep the value closer to 1uF.

If that doesn't resolve your problems then you need to show how you have everything wired. Not just a schematic showing the connections, but a picture of your setup.

When you don't have a serial device connected to the ESP, do you have anything to give a high to the serial RX pin of the module? A floating RX can cause problems.

Connecting a serial port to the module might be providing a ground to the circuit. It might have nothing to do with the serial port. Just the ground connection to the computer. Again, this is where it helps to see what you have done.

- Wed Nov 29, 2017 2:39 pm #72170 i dont think i understand what u mean?


"What pull up resistor do you have on the reset line? Do you also have a capacitor to ground, and if so then what value is the capacitor?"

a pullup resistor where? i've set up gpio 14 and 12 as input_pullup
i didnt put any capacitor. should i? and where?
tnnx

- Wed Nov 29, 2017 4:31 pm #72171 btw
i connected RX to 3v3
and now booting without problems
but
it doesnt seem to be a great fix.

why this problem?