The week has started well, the new Arduino Micro was already available in the lab so the development was carried out on the new board, meaning the Arduino Uno was left behind. After having the SPI communication established between the Arduinos, this part was merged with the code of the TCP/IP communication to ROS.
While doing this a new problem came across that was not detected previously: the SPI pins are used to the TCP/IP communication, witch means both parts can’t be merged!
Knowing that, a new protocol was used: I2C. It is a little bit slower than SPI, but has the advantage of connect multiple devices easily.
This protocol was implemented successfully with encapsulated messages (with special characters in the beginning and end), witch means the message can vary in length and still be recognized properly.
Note that the same method was used with the Ethernet communication between ROS and Arduino Leonardo ETH to prevent errors and make the data transmission more reliable.
On the rear of the vehicle there was a status panel giving information about the Robuter’s signals. On the picture below this can be observed.
On this rear part the following tasks took place:
- Removing the existent ultrasound sensors;
- Pinout the DB25 connector to match the wires to the PCB connection;
- Add roofmate to give resistance to the rear part. This way can absorb some unexpected impact;
- Study and alter the circuit to the new requirements;
- Extend the wires from the main connector and solder some resistors.
The improvements can be observed in the next pictures