In this article, you’ll learn how to build a system that can turn DC loads on and off using a mobile application. You’ll also learn how to perform this task via immediate actions or via timers set in advance for switching loads on and off.
You can implement this system in environments where you need to set your DC load for a specific time. This will allow you to use our Android application without any need for a hardware interface, keypad, and LCD screen.
This sort of touchpad speaks some special Apple mouse protocol. Luckily I found a code snippet on mikrocontroller.net which helped a great deal to get the thing going.
Then I used a standard AVR ATMega8 microcontroller to glue the transmitter and the touchpad together. That means, I poll the status/position change from the touchpad and if some swiping action was detected, the relative change of coordinates is sent via the radio.
I designed a compact double sided PCB housing both the microcontroller and the radio. It also features a 5V voltage regulator for the microcontroller and the power supply of the touchpad, as well as a 3.3V regulator for supplying the radio.
The touchpad is then connected to one of the free GPIO pins of the microcontroller which are accessible via dedicated pin headers
Over the past few years, the BeagleBone ecosystem has grown from the original BeagleBone White, followed two years later by the BeagleBone Black. The Black was the killer board of the BeagleBone family, and for a time wasn’t available anywhere at any price. TI has been kind to the SoC used in the BeagleBone, leading to last year’s release of the BeagleBone Green, The robotics-focused BeagleBone Blue, and the very recent announcement of a BeagleBone on a chip. All these boards have about the same capabilities, targeted towards different use cases; the BeagleBone on a Chip is a single module that can be dropped into an Eagle schematic. The BeagleBone Green is meant to be the low-cost that plays nicely with Seeed Studio’s Grove connectors. They’re all variations on a theme, and until now, wireless hasn’t been a built-in option.
This weekend at Maker Faire, Seeed Studio is showing off their latest edition of the BeagleBone Green. It’s the BeagleBone Green Wireless, and includes 802.11 b/g/n, and Bluetooth 4.1 LE.
As all the BeagleBones are generally the same, each with their own special bits tacked on, it’s only fair to do a line by line comparison of each board:
While the BeagleBone Blue is still in the works and due to be released this summer, the BeagleBone Green Wireless fills the WiFi and Bluetooth niche of the BeagleBone ecosystem.
As with any single board computer with a fast ARM chip running Linux, comparisons must be made to the Raspberry Pi. Since this is the first BeagleBone released with wireless connectivity baked into the board, the most logical comparison would be against the recently released Raspberry Pi 3.
The Pi 3 includes an integrated wireless chipset for 802.11n and Bluetooth 4.1 connectivity. The BeagleBone Green Wireless has this, but also adds 802.11 b and g networks. This gives the BBGW the ability to sense when anyone is using a microwave in the vicinity – a boon for that Internet of Things thing we’ve been hearing so much about.
Unlike the Pi 3, the BBGW has connections for additional antennas in the form of two u.FL connectors. While the Pi 3 can be hacked to use external antennas, it’s not a job for the faint of heart. The availability of external antennas in a small, compact, low-power format is the ideal solution for any wireless network connectivity dealing with range or a congested network.
The BeagleBone Green Wireless is a Seeed joint, and as with the original BeagleBone Green, there are Grove connectors right on the edge of the board. These connectors provide one I2C bus and one serial connection each for Seeed Studio’s custom modules.
To be honest, I’m of two minds when it comes to Seeed’s Grove connectors. On one hand, breadboards and DuPont cables already exist, and with the two 46-pin headers on the BeagleBone Black, there was nothing you couldn’t wire into the BeagleBone Black. The addition of Grove connectors seems superfluous, and in the most cynical view, merely an attempt to make a system of proprietary educational electronics.
On the other hand, there really isn’t any system of easy to use, plug-in modules for the current trend of educational electronics. Just a few years ago, people were putting out boards with RS-442 into RJ45 sockets. We don’t have DE-9 connectors anymore, and a smaller, easier to use connector is appreciated, especially when the connectors are a mere $0.15/piece.
Then again, the intelligence of a Grove module is purely dependant on the operator. On the BeagleBone Green, there are two Grove connectors, one for I2C, and another for serial. Apart from some silkscreen, there is no differentiation between these two connectors. On the Grove base cape, there are exactly four different implementations using the Grove connectors: four I2C, four digital I/O, with two GPIOs each, two connectors dedicated to analog input, and two serial ports. This is the simple way to connect a lot of devices via common wires; it is not the most user friendly.
The BeagleBone Green Wireless doesn’t really do anything new. The SoC is the same, and of course the PRUs in every BeagleBone are the killer feature for really, really fast digital I/O. The addition of WiFi is nice, and the inclusion of extra antenna connectors phenomenal, but it’s nothing a USB WiFi dongle couldn’t handle.
If anything, the BeagleBone Green Wireless is a signal for the future of the BeagleBone platform. The number of versions, each with their own small take on connectivity, is the bazaar to the Raspberry Pi’s cathedral. It’s encouraging for any fan of Open Hardware, and at the very least another tool in the shed.
The AAduino is an wireless Arduino clone the size of an AA battery with Keystone battery terminals rotated 180° to act as positive and negative terminals. It is powered by an ATMega328p and is fitted with an RFM69C companion. There is room for two DS18B20 temperature sensors and an indicator LED.
I want to be able to run openCPN on both a laptop and a tablet at the same time. I would like the laptop down below deck, safe from the rain and salt water spray. I would like to have a mostly waterproof tablet in the cockpit to monitor progress. And I would like to be able to quickly check the ship’s status from the captain’s berth when off watch, maybe on a smart phone.
The plan is to implement a device to read the serial data from all the boat instruments and send that data to openCPN over a WiFI link so there are no physical wires attached. It will broadcast the data with UDP so that multiple devices can read the data at the same time.
The ESP8266 ESP-01 was chosen because it was on hand and it has adequate I/O for this project.