ESP8266 Community Forum

Hi guys I bought a WEMOS R1 D1 an ESP Board in an Arduino form factor to play a little bit with this controller. I ran into some issues with my sensor setup and hope you guys can help me out. Since the formfactor matches this boards name I guess this is the correct place.

I compiled the test sketch of the ADXL345 sparkfun lib and loaded it onto my board. Looked into my serial monitor and I get reasonable results of -1 since no sensor is connected everything works as expected.
But as soon as I connect the sensor via spi a cannot upload any scetch nor do I get serial output.

Can anyone please help me? Thanks in advance.

Your description of your question is a bit vague, to say the least.
We do need actual sketches, schematics and photo's to get a clear picture of the problem.

Having said that: please keep in mind that the ESP is not the same as an ATMEL (the controler found on an Arduino board).
So though they made a PCB holding an ESP with the same form factor as an Arduino UNO (I know the board: I have the same one), there's no guarantee sketches and code is 1:1 interchangable.

For instance: the ESP has only has 11 free GPIO-ports and 1 ADC-pin while an Arduino has a multitude of digital and analog ports.

"But", you say, "the ESP has 17 GPIO-ports, not 11"?
No, actually 6 of them (GPIO6 - GPIO11) are used by the on-board SPI flash memory and if you'd also use them yourself for sensors, you'll crash the ESP.

Is GPIO15 used as the chip select for the SPI? If there is a pull up resistor on it, that can cause the ESP not to start in the right mode. GPIO15 is the actual ESP8266 designation and I think that is D8 on your board.

If that is the problem you can remove the resistor or you can add a lower value resistor from D8 to gnd. 330 Ohms should do it.

And if this is not the problem, then as stated above, we need more information.