@@ -102,6 +102,35 @@ The oven elements will be on all the time unless the oven overheats, so I implem
[video of the final thing]()
### Moving to the ESP 32 Board
I continued to have trouble getting samd based boards to work reliably with my computer. I switched out the Sunduino board for an ESP 32 based Wrover development board. In the process of doing this, I found and fixed a couple of errors in my relay board. I2C SDA was connected to the wrong pin on the Samd11. And I had forgotten to install a zero ohm bridge/jumper resistor.
Finally, I was able to get I2C to work! I tried 10k ohm pull up resistors but they didn't make any difference. The ESp 32 has internal pull-up resistors on I2C.
Here's a diagram of the hookup between the ESP board and the samd based relay board.
![Diagram of Samd hookup]()
Here'aa picture of the hookup:
![Pic of hookup]()
Here's a video of the whole thing working. I turn a potentiometer connected to the esp 32 board and it sends the potentiometer wiper voltage to the relay board. The relay board compares the wiper voltage to a set point - if the wiper voltage is higher than the set point the oven is off. Otherwise it is on.
[video of whole thing workign with I2C]()
The wiper voltage simulates a voltage divider based temperature sensor. If the oven temperature is higher than the maximum temperature for safe operation of the oven, the relay board shuts the oven element (in this case an LED that represents the element) off.
