I2C Buses
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Location of I2C Connectors and Headers
I2C Connectors
I2C1 interface connects to the outside via a 4-pin JST-GH as well as internally to the SE050 Secure Element. Note that there is also a second I2C bus described later on this page that comes from the SE050 itself.
Power output supply on I2C connectors:
The I2C1 and I2CSE interfaces include zero-Ohm resistor jumpers which can be used to select 5V (default) or 3.3V output on pin one. Note that the PWR output is intended for limited current supply and the overall power supply draw for external peripherals must be considered.
Connector P3 (I2C1):
Pin #
Signal
Specification
1
PWR
5V output default (3.3V optional)
2
SCL
3.3V
3
SDA
3.3V
4
GND
Connector P11 (I2CSE):
P11 is a I2C bus which is from the SE050 Secure Element device. It can be used for special applications such as encrypted sensor data.
Pin #
Signal
Specification
1
PWR
5V output (optional)
2
SCL
3.3V
3
SDA
3.3V
4
GND
I2C0 OLED Interface
This connector is for attaching the included I2C-connected 0.91" OLED display from the kit. These OLED displays use an SSD1306 type controller and information about their use is commonly available from online sources. Note that the pinout does not follow a standard, but most of them use the pinout chosen here. Please double check the pinout and orientation should you replace or use an alternative similar display.
Connector P4 (I2C0 - OLED)
Pin #
Signal
Specification
1
GND
0V (GND)
2
VCC
5V default (3.3V optional using R25)
3
SCL (I2C0)
3.3V (with weak 4 kOhm pull-up resistor)
4
SCK (I2C0)