The semester started last week. Ideally I wanted to have the boards for the new S robot (see “Zumo Robot with WiFi and GPS“) ready in the first week. But our manufacturer was not able to get the four-layer boards with parts populated and delivered in that time frame. Until the new boards arrive, we have anyway plenty of things to cover. One thing is to build a prototype shield to host several distance sensors, nRF24L01+ and Bluetooth transceiver:
Students will get the Eagle files, and then can adjust it for their own needs, and create their own custom board. The shield hosts several connectors for:
- Bluetooth module
- nRF24L01+ module
- I2C Sensor module
- Ultrasonic module
- 7 four-pin sensor modules
- Extended sensor module with 3 pins
Each of the module connectors have Vcc, GND and the digital (or analog) pins available. The connectors are designed for the Pololu infrared and distance sensors, but any sensors can be used. Several pins are directly connected to the shield pin rows. To extend the number of I/O pins, the I2C IO Expander IC PCA9554A is used.
The Shield is compatible with any Arduino (3.3V) or Freescale Freedom boards (e.g. FRD-KL25Z).We have two variants of the JY-MCU Bluetooth modules, so they fit in one or the other way:
With providing the Eagle files, I think this opens up for creativity. In any case, I have now a nice shield for my other FRDM boards so I can use them with external sensors, Bluetooth or the nRF24L01+ 2.4 GHz transceiver.
I have attached the schemata of the board: INTRO Robot Base Board Schematic.
Happy Shielding 🙂