- Wed Oct 18, 2017 11:20 am
#70947
helste wrote:> I think I must have been flashing something to an address that is responsible for the USB connection.
If communication between the onboard ESP12 and you computer is not working, the cause might be hardware and / or software-related.
-=[ Software part ]=-
For this part, it's important power the NodeMCU-board by an external power-supply (*).
1) When NodeMCU is connected, is it detected by Windows ?
"Silicon Labs CP210x USB to UART Bridge (Comx)", where x is a number.
2) When you tried to connect to the NodeMCU (onboard ESP12), did you select the correct COM-port ?
3) Are correct port-settings set ? Speed : like 9600 vs 115200 Bps.
(*) Yes, it's possible to power it solely over USB. An USB-port (v 1.0 / 2.x) can officially source a max of 0.5 Amps. Default the CP2102 is set to draw (if not mistaken) 50 milli-Amps from an USB-port, while using a few milli-Amps for itself to power up. But, and ESP12 requires sometimes more Amps, than your USB-port can supply.
To overcome this, you can go for 2 options :
A) Use a dumb USB hub
A dumb USB-hub is not power-protected. What I mean, there's a fair change a current-detection mechanism is not available, which limits the current to a max of 0.5 Amps. If you short the 5V and GND, there's no protection stepping in. If no short will occur, there's no problem, .. but if it does, you might get serious hardware-problems.
B) Change settings in CP2102
It is possible to modify settings in a CP2102. It requires a special tool to install.
-=[ Hardware-part ]=-
Steps to go :
1) Don't connect your NodeMCU to an external powersource (Vin).
We're going to check if a problem is located between USB-cable and Voltageregulator.
2) Connect your NodeMCU to an USB-cable (but not to PC)
The USB-socket at the NodeMCU-board contains 5 pins. One of the pins is not connected (pin 2 or 4, depends on how you look at it). If you hook this socket to an USB-cable, you get 4 pins at the computer-side. Use a multimeter to verify. If more than 1 pin not connected, use a new / other USB-cable.
3) Connect your PC with the NodeMCU-board, by USB-cable.
If correct, your PC detects an COM-port from manufacturer SiLabs.
If not :
- Verify if all 5 pins of the USB-socket at NodeMCU-board are well soldered.
- Verify if CP2102 is well soldered to board.
4) Check power from USB
Check if there's 4.7V between pin GND and Vin (multimeter).
If not :
- Verify if diode (near Rst-button) is well connected to board.
- Check if diode is defect (multimeter)
5) Check Voltageregulator (AMS1117)
Check if there's 3.3V between pin GND and 3V3 (multimeter)
If not :
- Check soldering at AMS1117 3.3. This is a black chip, 3 pins at one side, 1 pin at the other side.
- Check if nearby ceramic and tantalum capacitors are wel soldered
-=[ At the end ]=-
Well, if none of the above did help, yes, there's a fair chance the CP2102 died. You can order a new one and replace the defective one. Use an oven or hot-air soldering station.
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