107-Arduino-UAVCAN

Arduino library for providing a convenient C++ interface for accessing UAVCAN (v1.0-alpha) utilizing libcanard.

This library works for

• ArduinoCore-samd: Arduino Zero, MKR 1000, MKR WiFi 1010, Nano 33 IoT, MKR GSM 1400, MKR NB 1500, MKR WAN 1300/1310 ✔️
• ArduinoCore-mbed: Portenta H7, Nano 33 BLE ✔️

Example

Subscribe

#include <ArduinoUAVCAN.h>
/* ... */
ArduinoUAVCAN uavcan(13, micros, nullptr);
/* ... */
void setup() {
  /* ... */
  uavcan.subscribe<Heartbeat_1_0>(onHeatbeat_1_0_Received);
}
/* ... */
void onHeatbeat_1_0_Received(CanardTransfer const & transfer, ArduinoUAVCAN & /* uavcan */)
{
  Heartbeat_1_0 const hb = Heartbeat_1_0::create(transfer);

  char msg[64];
  snprintf(msg, 64, "ID %02X, Uptime = %d, Health = %d, Mode = %d, VSSC = %d", transfer.remote_node_id, hb.data.uptime, hb.data.health, hb.data.mode, hb.data.vendor_specific_status_code);

  Serial.println(msg);
}

Publish

#include <ArduinoUAVCAN.h>
/* ... */
ArduinoUAVCAN uavcan(13, micros, transmitCanFrame);
Heartbeat_1_0 hb;
/* ... */
void loop() {
  /* Update the heartbeat object */
  hb.uptime(millis() / 1000);
  hb.mode = Heartbeat_1_0::Mode::OPERATIONAL;

  /* Publish the heartbeat once/second */
  static unsigned long prev = 0;
  unsigned long const now = millis();
  if(now - prev > 1000) {
    uavcan.publish(hb);
    prev = now;
  }

  /* Transmit all enqeued CAN frames */
  while(uavcan.transmitCanFrame()) { }
}
/* ... */
bool transmitCanFrame(uint32_t const id, uint8_t const * data, uint8_t const len) {
  /* ... */
}

Service Client

#include <ArduinoUAVCAN.h>
/* ... */
ArduinoUAVCAN uavcan(13, micros, transmitCanFrame);
/* ... */
void setup() {
  /* ... */
  /* Request some coffee. */
  char const cmd_param[] = "I want a double espresso with cream";
  ExecuteCommand_1_0::Request req:
  req.data.command = 0xCAFE;
  req.data.parameter_length = std::min(cmd_param.length(), uavcan_node_ExecuteCommand_1_0_Request_parameter_array_capacity());
  std::copy(cmd_param.c_str(), cmd_param.c_str() + req.data.parameter_length, req.data.parameter);

  uavcan.request<ExecuteCommand_1_0::Request, ExecuteCommand_1_0::Response>(req, 27 /* remote node id */, onExecuteCommand_1_0_Response_Received);
}

void loop() {
  /* Transmit all enqeued CAN frames */
  while(uavcan.transmitCanFrame()) { }
}
/* ... */
void onExecuteCommand_1_0_Response_Received(CanardTransfer const & transfer, ArduinoUAVCAN & /* uavcan */) {
  ExecuteCommand_1_0::Response const rsp = ExecuteCommand_1_0::Response::create(transfer);

  if (rsp.data.status == ExecuteCommand_1_0::Response::Status::SUCCESS)
    Serial.println("Coffee successful retrieved");
  else
    Serial.println("Error when retrieving coffee");
}
/* ... */
bool transmitCanFrame(uint32_t const id, uint8_t const * data, uint8_t const len) {
  /* ... */
}

Service Server

#include <ArduinoUAVCAN.h>
/* ... */
ArduinoUAVCAN uavcan(13, micros, transmitCanFrame);
/* ... */
void setup() {
  /* ... */
  /* Subscribe to incoming service requests */
  uavcan.subscribe<ExecuteCommand_1_0::Request>(onExecuteCommand_1_0_Request_Received);
}

void loop() {
  /* Transmit all enqeued CAN frames */
  while(uavcan.transmitCanFrame()) { }
}
/* ... */
void onExecuteCommand_1_0_Request_Received(CanardTransfer const & transfer, ArduinoUAVCAN & uavcan) {
  ExecuteCommand_1_0::Request req = ExecuteCommand_1_0::Request::create(transfer);
  ExecuteCommand_1_0::Response rsp;

  if (req.command() == 0xCAFE) {
    rsp = ExecuteCommand_1_0::Response::Status::SUCCESS;
    uavcan.respond(rsp, transfer.remote_node_id, transfer.transfer_id);
  } else {
    rsp = ExecuteCommand_1_0::Response::Status::NOT_AUTHORIZED;
    uavcan.respond(rsp, transfer.remote_node_id, transfer.transfer_id);
  }
}
/* ... */
bool transmitCanFrame(uint32_t const id, uint8_t const * data, uint8_t const len) {
  /* ... */
}

How to generate C header files from DSDL via nunavut/nnvg

cd ~
https://github.com/UAVCAN/nunavut && cd nunavut
python3.8 -m pip install .

cd ~
git clone https://github.com/UAVCAN/public_regulated_data_types && cd public_regulated_data_types
nnvg --outdir include --templates c_jinja --pp-trim-trailing-whitespace -e .h uavcan