UART

Now, you should try using Tigard to speak with a UART console. Depending on what hardware you have lying around, you have a number of choices of how to do this.

In the video I used Screen to speak to serial consoles. On a Debian-based linux system, this means sudo apt install screen to get the tool and then screen /dev/ttyUSB0 115200 where /dev/ttyUSB0 is the device node for your adapter and 115200 is the baud rate for communicating.

Screen also works in MacOS and WSL; on windows you can use HyperTerminal or Putty. Minicom is another option on Linux systems

Try some or all of these project ideas for practice:

  1. Try it in ‘loobpack’ mode. This is a very handy test to make sure your tools and hardware are working properly.
    1. Take any one of the loose wires in your kit, and connect TX and RX to each other.
    2. Set the VTGT switch to 5v.
    3. Open screen or another program and start typing.
    4. You should see BOTH the TX and RX LEDs light up, and should get every character you send echoed back to you.
    5. Disconnect the jumper wire, and see how the behavior changes.
  2. If you have a device with a known UART, give it a try.
    1. You will need to connect a ground pin no matter what
    2. You next need to connect TX and RX. This is peer-to-peer, so remember to connect Tigard’s TX to the device’s RX and vice-versa.
      Note: TX and RX are indepentent. If you only want to listen, there’s no need to connect Tigard’s TX pin…
    3. You can *either* choose a voltage on Tigard *or* choose VTGT and connect the VTGT to your independently-powered target. In general, DON’T do both!
    4. Open screen or another program, and send some text to see what happens!
  3. Have a Raspberry Pi lying around?
    1. Take a look at the GPIO pins – It’s possible to communicate with the console on GPIO14 and GPIO15, usually pins 8 and 10 if the GPIO header.
    2. Be extra careful with the pin order – it’s NOT the same order as Tigard!
    3. You may need to modify the config.txt on your SD card to turn on the serial console
  4. Have an Arduino lying around (nearly any kind, not just uart-programmable ones)?
    1. Flash it with the AnalogInOutSerial sketch from the included Examples. It will now spit out UART data at 9600bps
    2. Connect ground and RX from your Tigard to ground and TX of the Arduino. You should see data coming out!
    3. If your Arduino is a Pro Mini or similar with a UART bootloader, you could also try programming it from Tigard as shown in the video.
    4. Try using different baud rates to get familiar with both the hardware and your software tools.
  5. Up for a challenge? Program an ESP8266:
    Tips: You’ll need to set pullup and puldown pins to get your ESP module into serial bootloader state, but once you’ve done that, you’ll need to use an ESP programming tool to send your firmware to the device. The Arduino ESP core is a good place to start.