About this project
Turn your Arduino into a powerful radio transceiver!
HamShield lets your Arduino talk to far away people and things using powerful amateur radio bands! Best of all, the hardware and software is open source!
With the power of Arduino, you can use the HamShield to build and invent amazing things in minutes! Here are some examples, right out of our sketch toolbox:
- Packet Radio
- Long range mesh networks
- Emergency communication networks
- High altitude ballooning
- Talk to repeaters
- Tracking devices (APRS)
- Interface the HamShield to your computer!
- Weather stations
- Remote controlled robots
- Automated satellite tracking and reception
- Weather satellites
- Scanning police, fire, business, FRS, GMRS, and MURS frequencies
- Logging and recording radio traffic
- Touchscreen handhelds
- Bulletin board systems
- New inventions!
The HamShield supports a wide range of VHF and UHF frequencies, covering 3 amateur bands. This includes the 1.25 meter or "220" band (220 MHz to 225 MHz), which is notoriously hard to find equipment for! It also can transmit on MARS bands.
Getting your Ham license is easy too! All that is required is a Technician license: http://www.arrl.org/getting-your-technician-license
The HamShield supports both voice and packet radio modes. You could even invent your own digital modes with enough skill. It is compact, lightweight, and works great with any Arduino or Arduino compatible that supports Uno-style shields.
The HamShield is the product of 12 months of design, engineering, and prototyping. This May 2015, we had our final design. We need your support to bring the economies of scale in our favor, fund the final development, part purchasing, and production of our shield, and help bring innovation back to Ham Radio.
With the HamShield, you no longer need a dedicated radio or piece of equipment for each type of operating mode. There is also no need for complicated radio interface cables. The radio is now under your complete control!
Practically no experience is needed to use the HamShield. Unlike other complicated, software defined radio boards, the transceiver core is a proven, commercial grade radio transceiver. There are a growing number of ready-to-use Arduino sketches we are actively developing. They are all ready to be uploaded to your Arduino!
As the community writes more Arduino sketches, this radio toolbox will grow. What will you write?
But the HamShield is even more powerful than just being the utility army knife of existing radio transceiver technology. The HamShield will bring true innovation back to Ham Radio, and yield new concepts and technologies.
Have you ever thought of a new, really cool, dream technology for amateur radio, but simply did not have the time, money or skill to take it to completion? Now, you can write a new program and bring it to life within minutes! We can't wait to see what people invent next with this shield!
The HamShield Transceiver
The HamShield is powered by the Auctus 1846S radio transceiver IC, which features a fully integrated FM radio transceiver. This amazing chip, with a software defined radio core, allows the ability to offer a wide range of features such as sub-audio CTCSS/CDCSS modes, DTMF encoding and decoding, tail noise elimination, RSSI, squelch, VOX, volumes, and even a very powerful tone encoder and decoder (which may be fast enough for some digital modes if you are creative enough!) Both 12.5KHz or 25KHz FM channel bandwidth can be selected. You can also leverage the powerful ADC and filtered PWM output circuitry for digital and audio modes right from your Arduino sketches! There is also no complex software defined radio processing required.
The HamShield is a wide band transceiver and can operate across the following frequency ranges at full power:
- 134-174 MHz
- 200-260 MHz
- 400-520 MHz
Contained within these ranges are three Ham Radio bands: 2 meter (144-148 MHz), 1.25 meter (220-225 MHz), and 70 centimeter (420-450 MHz)
While the HamShield is intended for amateur radio use, the shield can be used for prototyping new, non-amateur radio technologies in a lab setting, or possibly with use with an FCC granted temporary auxiliary license!
The Power Amplifier
The HamShield amplifier is a custom designed 250 milliwatt amplifier. This provides plenty of power for line of sight communications, as well as a high quality output for a variety of linear amplifiers. We felt this was the perfect match for power consumption on a small Arduino shield.
The audio can be accessed two ways, both of which can be configured to operate simultaneously:
Method 1: A built in TRRS jack that is compatible with nearly any hands free cell phone headset. You can also use a TRRS "cross over cable" to interface the audio to a laptop, tablet, or smartphone for on-the-go analog and digital operations.
Method 2: The Arduino can be directly interfaced to the audio. PWM output from the Arduino is smoothed and set to the proper audio level for input into the radio transmitter. Audio from the receiver is filtered and made available on an Arduino ADC line. This allows for interesting applications such as data and DTMF tone detection.
The HamShield uses the existing Arduino audio capability to transmit and receive packet radio data, which is featured in our HamShield library. While AFSK 1200 over FM is currently supported, with some ingenuity, new data capabilities can be invented.
Powering Your HamShield
Due to the amount of power required by the HamShield, it must be connected to an external power supply. Care was taken to make sure that the input voltage range was also within the output range of several different types of battery technologies, including 4xAA battery packs and 7.4 volt LiPo battery packs. The HamShield can operate between 5-30 volts DC, and is typically powered by a 12 VDC power adapter.
As an added feature, the HamShield's power supply is also fed into VIN on your Arduino. This means that the HamShield's power supply, including connected batteries, will power your Arduino and any other shields connected. Portable options, such as APRS GPS trackers, hidden transmitter hunting, and laptop APRS and packet radio are now possible.
The HamShield Arduino Library
The HAMShield Arduino library allows the user to control every aspect of the radio. The library handles all communication between the Arduino and the shield, so all you need to do is use our simple API. We have also created functions for common amateur radio modes, such as morse code, packet radio, SSTV, scanning, white space channel seeking, empty channel detection, and more! The capabilities of HamShield Library grow daily as we close in on the HamShield shipping date.
Here is an example Arduino sketch that transmits morse code every 10 minutes, assuming the channel is not busy:
Check out the video to see it in action!
Here is a tour around the features of our HamShield:
Control HamShield with your Laptop!
Our HamShield code also can turn your Arduino into a serial controlled radio. This allows you to download and write new laptop applications that leverage the flexibility of the HamShield, but may need the user interface or special processing power of a laptop computer.
We have also written an application that runs in any Chrome browser and can talk directly to the HamShield. This means that you can also use a low cost, low powered laptop (such as a Chromebook) to control your Ham Radio on the go! Bring HamShield on your next backpacking adventure! New, novel concepts such as "APRS Messenger" can bring multithreaded APRS text messaging anywhere you go!
Form Factor: Arduino-compatible stackable shield
Arduino Pins: I2C; GPIO, PWM and ADC
Frequency RX/TX: 134-174MHz, 200-260MHz, 400-520MHz
Amateur Radio Bands: 2 Meter, 1.25 Meter, 70 Centimeter
Power Output: 250 milliwatts (preliminary)
Radio SoC: Auctus A1846S
Channel Bandwidth: Selectable between 12.5KHz and 25KHz
Subaudio Modes: CTCSS, CDCSS (transmit/receive independent)
Advanced Features: Volume, Squelch, VOX, DTMF encode, DTMF decode, tail noise elimination, tone generator, tone detector, RSSI
Pre-Emphasis: Can be disabled to assist with digital modes
Antenna Connector: SMA, 50 Ohm (optional "rubber duck")
Audio Connection: Hardware selectable between TRRS (mobile phone style headset) and Arduino PWM/ADC inputs and outputs, PWM/ADC smoothing filters built in
Input Voltage Range: 5-20VDC, 4xAA, 7.4 volt lithium battery pack, power adapter capable (requires external power supply as Arduino does not supply enough power for shield)
Be sure to like HamShield on Facebook so you can keep up to date with future developments and example sketches!
The HamShield Team
Morgan Redfield (KG7OGM) is our lead electrical engineer. He has worked on many embedded hardware applications and is active in the Arduino hardware community. He received his MsEE from the University of Washington in 2013 and teaches robotics and electronics to high school students in his spare time.
Casey Halverson (KC7IBT) is an Information Technology professional and Amateur Radio operator. He earned his license when he was 14 years old. After working years with Arduino hardware, he dreamed of one day combining the rapid prototyping capabilities of the Arduino environment with Amateur Radio. Casey is also a Chrome developer, bringing the first Arduino IDE and programmer to the Chromebook (Chromeduino). His hobbies also include software development and electronic design.
Nigel Vander Houwen (K7NVH) is an Information Technology professional, and an extra class amateur radio operator. He studied Earth and Space Sciences at the University of Washington, and spends his hobby time working on interesting electronic projects, including specialty radio telemetry devices used for high altitude balloons and high power rocketry. A drive for knowledge pushes Nigel to create new things, and explore new places in the beautiful Pacific Northwest he calls home.
Q. Where will HamShield be manufactured?
A. In the United States. We have a contract manufacturer lined up to build HamShields in Seattle, Washington. We will also be purchasing most of our components from a well known distributor in the USA as well. Our main radio SoC is sourced from China.
Q. What if I want more than 250mW?
A. If you need more power, connect HamShield to a linear amplifier! While there are many products available for purchase online, we are looking for a partner who can help make this purchase process more streamlined. More information and options will be available when the survey is sent out after the project is funded.
Q. Does this work on any other bands, such as GMRS, FRS and MURS?
A. Yes, technically, the HamShield can transmit and receive on any frequency within its 3 band range. In the United States, these bands typically require a special equipment authorization and have certain emission restrictions.The library only allows transmission on amateur radio bands, unless the lock out is specifically disabled for a lab setting (using the .dangerMode() method). Please check with your regulatory agency and do not transmit on any frequency that you are not licensed for. You are always free to receive any of the supported frequencies with the HamShield.
Q. Can this work with just a computer?
A. Yes, as long as you still have an Arduino to plug the shield into. Our Chrome app will program the Arduino automatically, so it is plug and play. There is a "serial glue" sketch that allows a computer to control all aspects of the radio over serial port, as well as use packet radio functions available within our packet library. This makes things like our Chrome app possible. It also allows you to create computer controlled devices.
Q. How do I get two shields to work simultaneously?
A. Maybe, with some possible limitations. Your best bet is to use two Arduinos and connect via serial. The radios have not yet been tested collocated and all the audio would be connected together. You can change the I2C address by disconnecting a resistor and you will also want to space out the antennas. You would have to interconnect the two audio jacks with a crossover to build a repeater. Two boards could not work independently with system audio without some re-soldering.
Q. What other data modes are supported?
A. We currently have only tested AFSK at 1200 baud. Higher baud rates, such as 9600, have not been tested yet and may not be possible. While low pass filters and emphasis can be disabled in software, there is still a DC blocking capacitor between the chip audio lines and the shield audio circuitry. If this is bypassed, it might bring full FSK capability to the radio. However, this is outside what was recommended by the manufacturer. We do not expect this will damage anything.You are at your own risk with this one.
Q. Is this a software defined radio?
A. No, but this is a good thing. The Arduino is not powerful enough for Software Defined Radio. The A1846S actually has a software defined radio core to make this not necessary.
Q. Can this modulate SSB, AM, GMSK, etc?
A. No. Only FM is supported. FM is by far the most popular mode on all supported bands, so you will be able to participate with most of the activities taking place on the ham bands today.
Q. Can I use the HamShield as a scanner?
A. Yes! Although the circuitry is not designed for high speed scanning, we have several scanning functions built into the library. You could even write code to log transmission times and record transmission audio to a computer.
Risks and challenges
We have worked hard over the past year to make sure we were in the final stretches of development before asking the public for support. We have waited until a working prototype was completed, and that a reliable design can be brought to manufacturing. That being said, there can be all sorts of unexpected hurdles in hardware development.
Here are some potential risks and how we plan to address them.
Business, Budget, Finance
All of us have a small business ownership background in one shape or another and have business finance experience. We decided to launch our Kickstarter the "right way" by forming an LLC, obtaining a tax ID, and business banking services. We have a budget, modeled our potential income, identified pitfalls, created wiggle room within our budget, and have spoken to several different successful Kickstarter launchers about what problems they ran into. Our operating agreement places the liability of Kickstarter fulfillment the absolutely most important company priority.
Funding Over 100%:
We also have a plan in place under the very fortunate event that we overfund. We have the capability to produce thousands of boards, under the assumption that key critical components do not have unexpected lead time. Members of the team are dedicated to completing the project and fulfilling orders quickly, no matter the number of awards.
Electronic Hardware Production:
All project members have experience in electronic production and assembly, and have used contract manufacturers in the past to produce commercial and non-commercial electronic products in the past. While we do not claim to be experts, we know what it takes to successfully take a design from an idea to full production of hundreds or thousands of boards.
We have suppliers lined up, and to the best of our knowledge, should be able to produce all shields ordered without any problems.
Some potential risks could result in a design flaw, either introduced by our team or a design problem introduced by the contract manufacturer itself. We plan on mitigating this by performing slightly more expensive trial runs before producing the full amount of boards. Even in the event of the worst case scenario of a full production run with a defect, we will have enough reserve funds to complete fulfillment.
Sole Supplier Risks:
We now have a direct relationship with our main IC manufacturer. We have visited their factory in Shenzhen and have secured a supply of this key component. The chip is extremely popular and there are no signs of this becoming unavailable. This being said, if the main radio chip were to suddenly be end of life, have production problems, or other issues, we would have to perform a major board re-design. We would still be successful at releasing a shield product even with a major board redesign.Learn about accountability on Kickstarter
Support this project
- (30 days)