Overview

Let’s start with a quick tour of Tigard to become familiar with it’s core functions and features:

On your own, take a look at Tigard. Hold it so that the Tigard logo is upright:

  1. First, find the USB Type C connector on the left. This is how you’ll connect Tigard to your computer – but don’t do that yet.
  2. Clockwise around Tigard, next you’ll see a 4-way switch that lets you set the target voltage. I recommend keeping this in ‘VTGT’ mode until you’re ready to apply voltage to your circuit.
  3. Around the corner, you’ll find a GND test hook. This will be helpful if you find yourself debugging your signals with a logic analyzer or oscilloscope
  4. Next to the test hook is our first header – the UART interface. The header is a unique color to indicate it’s logically separate from all the other headers on the board. You have a dedicated harness that connects VTGT, GND, TX and RX with labeled wires. Most people only need these 4 wires, but should you require the additional hardware flow control signals, there are loose wires packed with tigard that you can add to your harness (though it does make the harness a bit more bulky when they’re added)
  5. Below the UART connector is the mode switch. This makes and breaks a few connections so that Tigard can work both in it’s standard mode (supporting JTAG and SPI) or in a special mode that uses bidirectional signals, for SWD and I2C. I keep it set to JTAG/SPI mode and only switch it when I know I need it.
  6. To the right you will find the CORTEX header. This is a standard 10-pin header that supports both JTAG and SWD (depending on how the mode switch is set). You should never need to worry about the pinout of this header – you’ll almost always use it with a 10-pin to 10pin 1.27mm pitch wire harness like the one included in your kit.
  7. Below that is the multipurpose JTAG header. This is the header that is most useful when you’re interfacing to various systems. The second included harness fits here, and has wires labeled for JTAG, SPI, and I2C. You might notice an additional hole without a pin – don’t worry about that now, that’s a special purpose pin just for programming ice40 FPGAs
  8. Around the next corner, you’ll find a 2×4 pin SPI header (It also doubles as an I2C header when the mode switch is set accordingly). It’s pins are oriented to match common 8-pin SPI and I2C chip footprints, so you can easily interface a socket or clip to this header
  9. At the bottom of the board is the Logic Analyzer header, labeled LA. This is designed to allow you to use the BitMagic Basic logic analyzer to watch the electrical protocol Tigard is speaking for debug purposes
  10. Finally, in the bottom left is the dedicated I2C header. This is compatible with STEMMA QT and Qwiic devices, and can be helpful for prototyping or reverse engineering libraries for communicating with I2C devices.

Now that you’re familiar with the different parts of Tigard, let’s walk through a number of different examples for using it!

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