Hardware to Connect Sensors and Actuators on CSR1011

This tutorial show how to build a hardware to connect sensors powered by 5V on the CSR1011.

Step 1: Source to Power CSR1011

A souce of 5V is used to powered the sensor. How the CSR1011 is powered by 3v3 a circuit to convert the 5v in 3v3 is required. The image attached ilustrate the electrical scheme of the source used.

Step 2: Connecting Actuators

The eletrical scheme attached represents the circuit used to connect an actuator on CSR1011. This circuit is required because the CSR1011 is powered by 3v3 and the actuator needs 5v to work. In this example was used a relay as an actuator. When the CSR sends a level high to the base of the transistor it get on the saturation region and the relay is powered by 5v. This circuit is also used to connect more than one actuator, because without external supply there is a draining of the current by the other actuator

Step 3: Connecting Sensors

The eletrical scheme attached represents the circuit used to connect a sensor on CSR1011. This circuit is required because the CSR1011 is powered by 3v3 and the sensor needs 5v to work. In this example, an infrared sensor was used. In this case, this sensor is used to detect the presence of an object, when this occur the sensor will send low level to the CSR's GPIO, otherwise the sensor sends high level to CSR's GPIO and in this situation the circuit is used to regulate the 5v to 3v3.

Step 4: Connecting Ultrasonic Sensor

The eletrical scheme attached represents the circuit used to connect the ultrasonic sensor on CSR1011. This circuit is required because the CSR1011 is powered by 3v3 and the sensor needs 5v to work. This sensor is used as a level sensor. To start the mesurement the CSR sends a pulse of high level with a duration of 10us to the base of the transistor that get on the saturation region and supply the sensor's Trigger with 5v, when this occur the sensor will send a ultrasonic pulse and set the Echo with high level and this state will be send to the CSR's GPIO, in this situation the circuit is used to regulate the 5v to 3v3. When the pulse return, the sensor will set the Echo to low level and send it to CSR again.

Step 5: Plugging the Circuits on the GPIO of CSR1011

The output of each circuit was connected to a slot as represented in the image attached. A Flat cable plugged in the slot connects the circuits on the CSR1011.