Hello,
I am using promini 3.3V to read data from a sensor and write it to SD card. The sensor works at 3.3 V too. When I upload the code to the micro controller , it runs perfectly as long as I use the bread board. I designed pcb for this setup and when I use the micro controller on a pcb, power it with a 3.7V battery, only the red light glows and nothing happens . I checked all the connections on the pcb and they are connected properly .
Can anyone please tell me what the problem might be ?
Thank you.
Hello,
The Vcc and gnd are not shorted. They are connected separately to respective pins. In the diagram it looks like that.
Thank you
Hello,
I have attached a picture of the schematic.
You do not have I2C pullup resistors. Going to be hard to get a high on those lines without one.
Check the unused IO on the DS3231, it may not be happy with floating inputs.
The LED needs a current limit resistor.
The buttons are using pinMode (pinX, INPUT_PULLUP) and the code tests for a LOW for a button press?
Hello ,
I use a 100 ohm current limiting resistor.
Also, I used pull ups for I2C 4.7
The circuit works perfectly on bread board.
It even worked on one of the PCB boards. On the second pcb board, the microcontroller red led glows, green led flashes and the red led of SD card also flashes continuously.
I am not able to figure out what the problem migh be. I checked all the connections and it were connected correctly.
" On the second pcb board, the microcontroller red led glows, green led flashes and the red led of SD card also flashes continuously."
The symptoms are with the same promini on both boards?
No. With different promini.
The promini which shows these symptoms worked on the breadboard correctly.
Post your code then, gotta be something flaky.
Use the code tag button, </> on the menu.
