No Wifi on MiniPCB v2 #wemos


Sam
 

Hi everyone. I'm building the MiniPCB v2 with Teensy 4.0.
I have uploade the Master version of Onstep and flashed the Wemos with 2.6.2 ver of ESP8266. All flashes were successful.

When I put it in the MiniPCB v2. Everything lights up except the Wemos. Proper voltages are being fed.D8 and D7 pins are recieving 1v from Teensy. 5v to GND is good. No pins are shorted and all components are fresh.

I tried also flashing with Onstep 3.16 but to no avail. Where could I start solving this problem?


YviundAlex@...
 

Sam,how do you power up the board? Via 12V or via USB over the Teensy?  I assume you checked the 5V directly on the board? (so no chance that the diode is in reverse polarity)
cheers
Alex


Sam
 

Thank you very much for the response!

The MiniPCB is run via power brick. Only use the Teensy MicroUSB during upload without the powerbrick connected. I also cut the needed traces to avoid powering the MiniPCB from the Teensy.

As mentioned by Khalid in a previous post here, I am using the recommended 19v 3.5A laptop power brick to power it.

Yes, the diode on the Wemos is connected as the silk screen indicates. The "white" part is facing the 5v and GND pins. I have also verified 5.1/4.8v out of the 5v-GND pins.


YviundAlex@...
 

Just to clarify, what do you mean by 5V out of the GND pins? If you power up the WEMOS alone with out the rest, just by USB, does it work thaN?


Sam
 

On Mon, Apr 26, 2021 at 12:52 PM, <YviundAlex@...> wrote:
Just to clarify, what do you mean by 5V out of the GND pins? If you power up the WEMOS alone with out the rest, just by USB, does it work thaN?
The 5v to GND pins on the MiniPCBs female header sockets for the Wemos.

Yes, it works when plugged in via USB. I was able to flash it and see the default "ESPxxxx..." SSID.


Mike Ahner
 

On Mon, Apr 26, 2021 at 10:18 PM, Sam wrote:
Yes, it works when plugged in via USB. I was able to flash it and see the default "ESPxxxx..." SSID.
It appears the ESP wifi board is working. I would check the solder connections for RX/TX pins on the Wemos, the Teensy, and the pcb. You can check with a continuity meter or just examine them closely with a magnifier/bright light and then touch up any questionable connections with a soldering iron.

Also, you might double check that you have RX/TX to the correct pins, normally they are swapped between the Wemos and the pcb/Teensy, e.g. ESP RX-> Teensy TX and ESP TX -> Teensy RX.

You can swap these if you are unsure, it won't damage anything, but if they are now swapped, the 2 devices will never communicate.
-Mike


YviundAlex@...
 

Sam, I know what a GND pin and what a 5V PIN is :), but not what a 5V to GND pin is, but than I'm not native speaking....besides the good idea of Mike checking TX and RX, could you please measure against GND your voltages on PIN 8, 9 and 10 and post them here? 
Thanks
Alex


Sam
 

UOn Mon, Apr 26, 2021 at 08:36 PM, Mike Ahner wrote:
On Mon, Apr 26, 2021 at 10:18 PM, Sam wrote:
Yes, it works when plugged in via USB. I was able to flash it and see the default "ESPxxxx..." SSID.
It appears the ESP wifi board is working. I would check the solder connections for RX/TX pins on the Wemos, the Teensy, and the pcb. You can check with a continuity meter or just examine them closely with a magnifier/bright light and then touch up any questionable connections with a soldering iron.

Also, you might double check that you have RX/TX to the correct pins, normally they are swapped between the Wemos and the pcb/Teensy, e.g. ESP RX-> Teensy TX and ESP TX -> Teensy RX.

You can swap these if you are unsure, it won't damage anything, but if they are now swapped, the 2 devices will never communicate.
-Mike
How do I swap the pins?
Although I am able to measure continuity (without and with the modules) between these pins.


Sam
 

On Mon, Apr 26, 2021 at 10:15 PM, <YviundAlex@...> wrote:
Sam, I know what a GND pin and what a 5V PIN is :), but not what a 5V to GND pin is, but than I'm not native speaking....besides the good idea of Mike checking TX and RX, could you please measure against GND your voltages on PIN 8, 9 and 10 and post them here? 
Thanks
Alex
I was measuring 5v to GND pins on these:


Sam
 

On Mon, Apr 26, 2021 at 10:15 PM, <YviundAlex@...> wrote:
could you please measure against GND your voltages on PIN 8, 9 and 10 and post them here? 
Thanks
Alex
Do you mean this?


YviundAlex@...
 

Good idea with the photo...do you have a picture pof both sides of your soldered PCB?

I would like to see measurement taken here (in green) against a GND pin, examples in yellow


philippe.larrieux@...
 

I may be wrong, but if you still see the default "ESPxxxx" SSID after flashing, it means that flash didn't work, you should not see default ESPxxxx SSID anymore.


Sam
 

On Tue, Apr 27, 2021 at 12:04 AM, <YviundAlex@...> wrote:
Good idea with the photo...do you have a picture pof both sides of your soldered PCB?

I would like to see measurement taken here (in green) against a GND pin, examples in yellow
C2 - 5v (4.384v)
C2 - 3.3v (3.315v)
C2 - GND (0v)

C6 - 5v (4.384v)
C6 - 3.3v (3.315v)
C6 - GND (0v)

C7 - 5v (4.384v)
C7 - 3.3v (3.315v)
C7 - GND (0v)

All where tested while the modules (Wemos, Teensy, Stepper Driver) were plugged in.
 


Sam
 

The default SSID came up for only a short while during flashing. I am not sure if it was before the upload or after. I am not seeing it anymore though.


Sam
 

On Mon, Apr 26, 2021 at 11:38 PM, Sam wrote:
On Mon, Apr 26, 2021 at 10:15 PM, <YviundAlex@...> wrote:
could you please measure against GND your voltages on PIN 8, 9 and 10 and post them here? 
Thanks
Alex
Do you mean this?
I measure the voltages on the Teensy 8, 9 and 10 pins to GND on the C6 capacitor as well as the GND beside the Teensy 5v VIN pin.

GND to Pin 10 (3.299v)
GND to Pin 9 (3.300v)
GND to Pin 8 (0.1v or 1mV)

When I use the GND near Pin 0 on the Teensy board I get 1-7 mV.


YviundAlex@...
 

These values look good to me, as they show that the WEMOS gets power and itself powersup its own 3.3V buck converter...

Don't forget the pictures of both sides of the PCB


Sam
 

On Tue, Apr 27, 2021 at 01:01 AM, <YviundAlex@...> wrote:
Don't forget the pictures of both sides of the PCB
Almost forgot:


YviundAlex@...
 

gmm beside the soldering of the cap I cannot see anything strange, which cannot rule out a bad soldering, as this ould need a more closeup...
but: Any chance for you to get oscilloscope data of RX and TX?
If not, do you have a breadboard handy where you could test just the teensy and the WEMOS?
We have to partition somehow your problem....I do not have a WEMOS here to test the info I would get while flashing....
cheers
Alex


Sam
 

On Tue, Apr 27, 2021 at 02:38 AM, <YviundAlex@...> wrote:
gmm beside the soldering of the cap I cannot see anything strange, which cannot rule out a bad soldering, as this ould need a more closeup...
but: Any chance for you to get oscilloscope data of RX and TX?
If not, do you have a breadboard handy where you could test just the teensy and the WEMOS?
We have to partition somehow your problem....I do not have a WEMOS here to test the info I would get while flashing....
cheers
Alex

Thank you again for the continued help on this.

The soldering is good based on folks at r/soldering haha but I have a second board that I can make just to rule out bad board/solder work.
I do not have an oscilliscope, unfortunately.
I have a breadboard, how should I test the Wemos and Teensy?


YviundAlex@...
 

I thought more about it...should we try first if you really can successfully flash soemething onto the WEMOS?
This program should have the internal LED blinking
Can you try this code and confirm that the LED is blinking with 2 sek intervall?
// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // Arduino: turn the LED on (HIGH)
                                     // D1 Mini: turns the LED *off*
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // Arduino: turn the LED off (LOW)
                                     // D1 Mini: turns the LED *on*
  delay(1000);                       // wait for a second
}