How to Program ATtiny Microcontrollers Using IC Test Clips

There are multiple ways to program a product when it comes to high volume production. In a previous article, we showed you a homemade test PCB that could be created to program an ATtiny. In this article, we will delve into the actual methods of programming an ATtiny MCU.

One of the challenges of programming SMD ATtiny microcontrollers is that they cannot be plugged directly into an Arduino board like an ISP programmer or dedicated ISP programmer can.

The ATtiny MCU lacks pins for interfacing with jumper wires or a breadboard. However, there are a number of ways to interface with an SMD microcontroller, even if it is soldered to a PCB. In this first programming method, we will show you how to program an ATtiny using a tool called an SMD test clip.

What is an IC test clip?

The IC test clip itself is a spring clip with multiple sets of electrical contacts inside the jaws. They are designed to fit specific SMD packages.

IC test clip.

The test clip hooks onto the microcontroller IC and allows connections to be made using the SMD pins. Using this tool, an SMD microcontroller can be connected to an ISP programmer just like a through-hole package.

The test clips are connected to the pins of the ATtiny on the test PCB.

Programming a microcontroller using an IC test clip is useful for working with assembled PCBs.

Typically, the IC test clip method is used for late-stage prototypes built on assembled PCBs for final functional testing. This method can also be used for small production runs involving a manageable number of boards. Note that it does take several minutes per board, so it would be too expensive to produce this way in terms of run time.

How to properly connect an IC test clip to an ATtiny

The first step in programming a microcontroller with the IC test clip is to properly connect the test clip to the microcontroller.

The orientation of the clip is important. Usually, IC test clips will have a marking near the jaws, or if one wire will be a different color than the other.

On an IC test clip, one wire is usually a different color than the other wires.

The mark or odd-colored line is closest to the point on one corner of the microcontroller IC.

Running ATtiny on Arduino IDE

On the software side, if you are using the Arduino IDE, you will need to burn the Arduino Bootloader onto the chip.

To program, connect the IC test clip to the microcontroller, connect the programmer to your computer, and select Tools > Burn Bootloader in the Arduino IDE.

To connect the ATtiny to the Arduino IDE, select Tools > Burn Bootloader.

Upload the Sketch program to the ATtiny MCU

Uploading a Sketch from the Arduino IDE to your ATtiny microcontroller using the IC test clip works the same way as uploading a sketch to an Arduino board. First, select your board from the Tools menu, along with any other applicable options (such as clock speed).

Select the type of "board" from the Tools menu.

Once you have selected the correct microcontroller, simply press the Upload button to program the chip with the Sketch you wrote. Just like uploading to an Arduino board, the IDE will give you a confirmation message when the upload is complete or if there were any errors.

When to choose the IC test clip method

The IC Test Clip can be used to program an ATtiny series microcontroller that has been soldered to a PCB, making it useful for programming prototype PCBs.

The IC Test Clip allows the pins on an SMD microcontroller to be broken out and then connected with an ISP or AVR programmer.