BioBoost/trex-controller

NodeJS package for controlling the TRex Motor Controller of the Thumper platform

Thumper TRex Controller

NodeJS package for controlling the TRex motor controller of the Thumper platform.

Important

This package is meant to be used with the new TRex thumper-v4 firmware which can be found at https://github.com/BioBoost/thumper_trex_firmware/tree/thumper-v4.

Usage Example

import { TRexController } from '@thumper/trex-controller';
import i2c from 'i2c-bus';
import { BytesRead, BytesWritten } from '@thumper/trex-controller/lib/i2c-device';

console.log("Starting service ....");

class I2CBusWrapper {

  address: number;
  bus: i2c.PromisifiedBus | undefined;

  constructor(address = 0x20) {
    this.address = address;
  }

  open() : Promise<I2CBusWrapper> {
    return new Promise((resolve, reject) => {
      i2c.openPromisified(1).
      then((bus) => {
        this.bus = bus;
        resolve(this);
      }).catch((reason) => {
        reject(reason);
      });
    })
  }

  read(buffer: Buffer, length: number): Promise<BytesRead> {
    if (!this.bus) throw new Error('I2C Bus is not initialized!');
    return this.bus.i2cRead(this.address, length, buffer);
  }

  write(buffer: Buffer, length: number): Promise<BytesWritten> {
    if (!this.bus) throw new Error('I2C Bus is not initialized!');
    return this.bus.i2cWrite(this.address, length, buffer);
  }

  close() {
    if (!this.bus) throw new Error('I2C Bus is not initialized!');
    return this.bus.close();
  }
}

let i2cBus = new I2CBusWrapper(0x20);
let controller = new TRexController(i2cBus);

i2cBus.open().
then(() => {
  controller.battery()
  .then((voltage) => {
    console.log('Voltage = ' + voltage);
    console.log('Backwards ...')
    controller.backwards(20);
  })
}).catch((err) => {
  console.log(err);
})

try {
  setTimeout(async () => {
    console.log('Going forward ...')
    await controller.forward(20);
    const voltage = await controller.battery();
    console.log('Voltage = ' + voltage);
    console.log('Stopping')
    await controller.stop();
  }, 2000);
}
catch(e) {
  console.log(e)
}

setInterval(async () => {
  console.log('Keeping alive ...');
}, 5000)

process.on("SIGINT", async () => {
  console.log('SIGINT');
  console.log("Stopping controller ....")
  await controller.stop();
  console.log('Closing bus')
  await i2cBus.close();       // This fails for some reason
});

process.once('SIGTERM', async () => {
  console.log('SIGTERM');
  console.log("Stopping controller ....")
  await controller.stop();
  console.log('Closing bus')
  await i2cBus.close();       // This fails for some reason
});

Dependencies

Tried following packages with RPi4 64 bit:

• rpio: Read works like a charm, write messes up the i2c bus
• @abandonware/i2c: Segmentation fault
• array-gpio: mmap error: Operation not permitted, The kernel parameter iomem=relaxed disables the address checking. Adding it to the cmdline.txt - TRIED - DOESNT SEEM TO WORK

For the moment the only library working was i2c-bus.