“Wireless communication has become a key feature in our projects nowadays and talking about wireless, the first thing that comes to my mind is Wi-Fi or BT, but handling the Wi-Fi or BT communication protocols is not an easy task and consumes a lot of MCU resources, leaving small space for coding my application. Therefore, I usually opt for an external Wi-Fi/BT module serially connected to the microcontroller in order to split the roles and gain higher freedom.
However, sometimes Wi-Fi and BT are overkill for some applications requiring low bitrate and short communication distance. Furthermore, using Wi-Fi or BT implies the necessity of connecting your Smartphone or device with proper authentication.
Imagine that you simply need to turn on/off an external light, or change the lamp light intensity, or open an electric gate. Would it be worth to use Wi-Fi or BT?
Depending on the environment and applications, wireless communication over IR (Infrared) wavelength might come at handy. A Serial over IR, implemented with few external components (5 discrete components!), and uChip(a very small Arduino compatible board) can be the solution you were looking for!
Bill of Materials (for one Tx-Rx device):
1 x uChip
1 x IR LED: having the emission peak at 950nm
1 x TSOP-38238 (of equivalent)
1 x BJT NPN: the standard BC547 or equivalent
1 x 10KOhm Resistor
1 x 1KOhm Resistor
Hardware:
1 x breadboard/proto board
1 x Plastic Hose: inner diameter the same size as the IR LED, the tube is necessary to prevent cross-talk with the TSOP receiver.
1 x Aluminum Foil (3cm x 3 cm)
1 x Tape
TIP: You can make an only-TX or only-RX device in case you need a one-direction communication by removing the unnecessary RX/TX from the circuit or disabling it in the code.”