Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By craiglindley
#33721 Hello,

I'm trying to connect a NodeMCU Amica to a OV7670 image sensor without FIFO. In trying to make this work I've come across an interesting issue with booting/uploading code.

I have the 3.3 and gnd connected from the Amica to the camera module and I have successfully used the Wire library to talk to the camera's i2c type interface. However if I connect a data out line from the camera to pin D7 of the Amica the Amica will neither boot or upload code. If I add a switch to the reset line of the camera module and hold the camera in reset, boot and upload works as expected. If I then remove the reset the code runs. If however I remove power by unplugging the USB cable and plugging it back in the Amica will not boot.

So my question really is how can activity on D7 prevent the Amica/ESP8266-12 from booting and/or running?

Any info would be appreciated