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C.H.I.P Pro Dev Kit Intro

This documentation is a resource to getting started with the C.H.I.P Pro Developer’s Kit. There are lists of contents, descriptions of parts, explanations of how to use the unique features of the board, and some examples to work through so you can get up and running developing your product around C.H.I.P Pro.


The C.H.I.P Pro Developer’s Kit provides a complete electronic sandbox to test, iterate, and prototype products with the C.H.I.P Pro module. While many developer’s kits assume a high-degree of technical experience, we make this kit approachable, compact, and easy to use. We believe that great products can come from many backgrounds, so we provide several extras in this kit that help you get making and get comfortable. We even include an extra C.H.I.P Pro to get you started on your own PCB. If you do know it all, you’ll find this documentation will help your product be the best it can be, whether you’re making 1 or 1 million.

Contents: C.H.I.P Pro

If you need information unique to the C.H.I.P Pro module itself, such as schematics, specifications, dimensions, complete pin descriptions, a comparison between C.H.I.P and C.H.I.P Pro, and more, visit the C.H.I.P Pro documentation site.

What’s in the Kit

C.H.I.P. Pro Dev Kit Package Contents

The C.H.I.P. Pro Dev Kit comes with accessories to get you started on your first prototype:

What’s on the Board

C.H.I.P. Pro Dev Kit Features

Front Callouts

Pin Headers

Pin Headers

There are several areas where pin headers can be soldered into through-holes for easy access and control of the pins on C.H.I.P. Pro.

Cuttable Traces

The C.H.I.P. Pro Dev Kit is designed to be flexible for your design and provide valuable built-in hardware. There are several cuttable jumpers that will disconnect onboard components and reroute power and data to where you need. You can find all of the jumpers outlined in the images below.

Most of these traces are on the back of the board with one very important exception. The USB0 jumpers on the front are connected to the micro-USB0 port on the Dev Kit. This renders the micro USB port on the C.H.I.P. Pro itself unusable. If you would like to use the micro-USB port on C.H.I.P. Pro these must be cut.

Front Callouts

Front Traces

Back Traces

How to Cut

Here’s what you need to know about modifying and repairing the traces on the dev kit to experiment and test different configurations.


To get the job done, you need to grab an X-acto knife or another small, sharp blade. The goal is to cut the trace connecting the two solder pads while NOT cutting anything else. The area to cut is very small so if you happen to own a pair of magnifying eye glasses now is the time to use them! To help stay in one place and not accidentally run the blade over another trace think of the cutting action as more of a digging action.

Cut Jumper

When you feel like you may have successfully cut through test the connection with your multimeter to confirm the disconnect.

Test Jumper


Some of these require both a trace cut and a solder bridge. For example, the MIC1 power has three pads. Cut between two of the pads, and bridge two with solder.

Solder and Cut Jumper

Revert and Repair

Once you cut a trace it can be reverted to the original behavior. To replace the jumper solder a small piece of wire across all the contacts you wish to reconnect, or, if you are nimble, bridge the contacts with a solder blob.

Solder Bridge

Flash With An OS

Before you start building with the C.H.I.P. Pro Dev Kit the C.H.I.P. Pro needs to be flashed with an operating system. Grab these items, then read on:

Flash an Example

You can select an OS and example from in Chrome or Chromium browser.

Plug the micro USB cable into the USB0 port on the Dev Kit (not in the C.H.I.P. Pro!). Hold down the FEL button and with the other hand plug the USB cable into the computer. The C.H.I.P. Pro will power up which will be indicated by the pink power and white status LEDs illuminating.

pushing FELL button

The web flasher will search for and eventually recognize your board. Keep holding the FEL button down until the magnifying glass goes away and you have an option to choose an image to flash.

Choose one of our three delightful examples:

Except for the Debian example, when you connect to C.H.I.P. Pro via serial, you will be logged in as root.

If you want to learn more about C.H.I.P. Pro software, such as connecting to WiFi and accessing GPIO, head over to the official C.H.I.P. Pro Docs page.


Controlling LEDs is fundamental to almost any hardware. This simple example provides easy-to-understand code with exciting results! Flash C.H.I.P. Pro with this image and watch the GPIO D0-D7 lights turn on and off in a cascading pattern and the two PWM LEDs pulse from dim to bright.

There are two scripts running in the background. If you want to modify the code for this example, connect via USB-serial and then you can use the vi editor to play around with the code:

vi /usr/bin/blink-leds
vi /usr/bin/fade-pwms

This image is a very rudimentary Linux distribution, based on buildroot. It demonstrates a fast-booting system that boots into a software system that immediately controls hardware.

VU Meter

Want to make sure your Mics are working? Use this handy VU Meter example. Scream loudly, speak softly, tap the mics, and MAKE SOME NOISE, SPORTSFANS! You’ll see the LEDs light proportional to the volume of the noise captured by the two built-in mics.

If you want to modify the code for this example, connect via USB-serial and then you can use vi to edit it:

vi /usr/bin/vu-meter

This image is a very rudimentary Linux distribution, based on buildroot. It demonstrates a fast-booting system that boots into a software system that reacts to the environment and controls hardware.


We provide a standard Debian distribution, complete with all the package managers and conveniences you know and love. This package is ideal for development, since it is more flexible than the buildroot-based Gadget OS. However, you will want to keep track of your dependencies to more easily transition to the more nimble Gadget OS.

When you connect to C.H.I.P. Pro, you can log in with username chip and password chip.

If you want to configure and build the kernel and rootfs for the Debian image, take a look at our github repo



There are three ports on the Dev Kit that support three different power supplies:

For AC adapters we recommend getting one that supplies 12V and 3 amps.

Power can also be provided to three pins to power C.H.I.P. Pro.


The C.H.I.P. Pro Dev kit can provide power to sensors and peripherals.


There are several ways to power the C.H.I.P. Pro Dev Kit and your creative endeavors. The Dev Kit boasts a AXP209 Power System Management IC designed to switch to any available power source. The following table details what happens with some different power scenarios.

Power Source Result
Battery C.H.I.P. Pro is powered by battery
Battery + DC In C.H.I.P. Pro is powered by DC In, battery is charged
Battery + USB In C.H.I.P. Pro is powered by USB in, battery is charged (though more slowly than by DC In)
Battery + DC In + USB In C.H.I.P. Pro is powered by DC In, battery is charged
Battery + low amperage DC or USB In Battery powers C.H.I.P. Pro as needed to prevent shut down
Too much voltage! C.H.I.P. Pro shuts down and may become permanently damaged

Powering Off

If you are running any processes we recommend powering C.H.I.P. Pro off by holding the C.H.I.P. Pro power button on the dev board down (for about 6 seconds). Wait for the power and status LEDs to turn off. Alternatively, you can switch off C.H.I.P. Pro through software using the command poweroff. In both instances, once C.H.I.P. Pro has been powered down it is safe to remove the power supply from the Dev Kit without the risk of losing data.

Connect and Control

C.H.I.P Pro is a headless computer, so you will need a separate computer in order to interact with it. The Dev Kit makes this easy and powerful, with a built-in USB to Serial converter for a direct connection to UART1. Connect the board to your computer with a common USB A to Micro-USB B cable. You can instantiate a UART connection with C.H.I.P Pro powered on or off. If you set it up before you power C.H.I.P Pro, you’ll be able to see all messages starting from boot.

The topics in this section cover features that are unique to the Dev Kit. Other topics, such as connecting to a network, USB Gadget serial connections, and using GPIO are covered in the C.H.I.P. Pro documentation

USB-Serial (UART1) Connection.

There are several applications you can use to make a USB-serial terminal connection to the Dev Kit. Below are some of the most common.

OS X & Linux

Connect the Dev Kit to your computer and open a terminal window. Find out the tty.usbserial dev path the Dev Kit is attached to by using the command below or use the tab key to autocomplete, like screen /dev/tty. <tab>

ls /dev/tty.*

On Linux, this is usually ttyUSB0, and on OS X, something similar to usbserial-DN022CZ9. On Debian systems, you may need to install screen:

sudo apt-get install screen

Use Screen to create a serial terminal at 115200 bps:

screen /dev/tty.usbserialxxxxxxxx 115200

Log in to C.H.I.P. Pro using the default user and password chip.

Exit Screen

When done, press Ctrl+A then Ctrl+\ to kill all windows and terminate Screen. If you get the error “Cannot open line… Resource busy” it’s because the last session was not properly exited. Search for the open file and active process using usbserial:

lsof | grep usbserial

You will get an output that looks something like this:

screen  27127 Sefi  5u  CHR             18,0        0t0     605 /dev/tty.usbserial

Note the process ID. In this case, it’s 27127. Then run:

screen -x 27127 

It will return to your previous screen session. Then use Ctrl+A Ctrl+\ to close it properly (will ask you to confirm).


Download the PuTTY terminal emulator or Cygwin.

Open your Device Manager and find the port labeled USB Serial to find the COM port number. The items to plug into either Cygwin or PuTTY are:


The C.H.I.P. Pro Development Kit has several ways to access audio in and out. Stereo audio in and out is handled by a 24bit/48K DAC built-in to the GR8 processor. There are also digital options that you can use, but require configuration of the Linux kernel and additional hardware to access.


There are two (2) analog MEM (micro electro mechanical) microphones on the Dev board. These are enabled by default.

If you want to use the MIC1 and MIC2 pins for audio input, you’ll need to cut a trace.

The “Sleeve” (bottom-most ring) on the TRRS jack can be used as a mono audio input, suitable for microphones commonly built-in to headphones. If you want to used this connector, you’ll need to cut a trace.


The 3.5mm TRRS jack provides stereo output suitable for headphones or amplification to stereo speakers.


The USB A jack can be used to connect and use popular accessories like storage, MIDI controllers, keyboards, pointing devices, audio hardware, and more. C.H.I.P. Pro does not provide power to the USB A port on its own, so the Development Kit is a good example of how this works.

On-board LEDs

The Dev board provides ten LEDs to make it easy to test your GPIO skills without having to wire anything up.


Eight of these LEDs can be turned on and off with standard Linux sysfs commands to the GPIO pins DO to D7.


There are also two LEDs that are connected to the PWM pins for testing and learning about pulse width modulation.

Make it with C.H.I.P. Pro!

The Dev Kit board contains hardware to make rapid prototyping with C.H.I.P. Pro a unique experience. When it comes to software however, the C.H.I.P. Pro and Dev Board are the same. To learn more about C.H.I.P. Pro, such as connecting to WiFi and accessing GPIO, head over to the official C.H.I.P. Pro Docs page.

Open Source

The C.H.I.P. Pro is open source hardware. Get all the details in our github repo.