Today I received the ESP8266EX Serial -> WiFi modules! After not being convinced by the rather expensive Adafruit TI CC3000 (35USD!) module I am now very curious about these tiny and cheap (<4USD) modules.
As their default header (2X4 male) is not exactly breadboard friendly, I sat down today and soldered a simple breadboard adapter. All you need is a tiny piece of stripboard 4×4, two male headers 1×4, two female headers 1×4 or one female header 2×4, and a bit of hot glue.
Cut the stripboard to the correct size (4×4) and sandpaper any rough edges. Use a file to separate the copper strips across the middle.
Place the female header on a breadboard using the male headers to give it some stability and solder it to the stripboard. Watch out for the correct orientation!
Re-align the plastic spacer of the male headers all the way to the top.
Place the stripboard with the male headers inserted from the non-copper side on some support (I used my vice for this).
Solder the male headers to the stripboard.
Now replace the plastic spacer of the male headers to the bottom side and push it as far up as possible (it probably will not go all the way because of the solder)
Add some hot glue around the tips of the male headers to provide additional support and strength.
The first tests using the Bus Pirate as UART bridge worked fine. I could talk to the module and connect to my home WiFi via WPA2.
Last weeks EclipseCon Europe in Ludwigsburg, Germany was great! Thanks to all those active contributors, who made this event possible. Additional to the usual Java and Eclipse topics, there were very interesting sessions on the Internet of Things, web technologies, and OSGi.
A live demonstration of Docker providing a very flexible infrastructure for Eclipse RT applications. I recently had the chance to try out Docker and it is really amazing. If you are looking for a lightweight and highly flexible alternative to virtualization on Linux, try this!
All in all, with the great conference food, the entertainment with Circus Eclipse and the rock-band Cool Down, and the great speakers and participants, this is an event I am already looking forward to in 2015!
After the Maker Faire, I went back to the Graupner mc-17 remote control.
The arduino library from tronixstuff for the KTM-S1201 LCD which is also using a mPD7225 controller was a good starting point. But to get the LCD up and running, it took quite a bit of fiddling and logic sniffing.
Once the controller allowed me to switch on individual segments of the LCD, I needed to adapt my implementation to this specific display, as it offers remote control specific elements unusual for normal LCDs. With a proper mapping of bits and bytes to their respective LCD elements, it was easy to implement the usual alpha-numerical characters. Each of the digits is controlled by a word / two bytes. For each byte, one bit is used to control one of the additional symbols like colons, dots, or remote controls specific texts.
Thanks to all those organisers who made this awesome event possible!
After we set up our stand in the morning, we were busy until the very end. There was constant buzz of kids around, who wanted to try the ROV and steer it into one of the bucket-caves we set up in the pool. Just around closing time a managed to have a quick tour of the other stands. So nice to see all this creativity around, reminds me of the Chaos Communication Camp in 2011.
Heading out to the after-party now 🙂
PS: talking about the Chaos Communication Camp, who from Trondheim region would be interested in going there next year? I set up an etherpad here: https://pad.fnordig.de/p/trdccc15
Last preparations for the upcoming Trondheim Maker Faire 2014. In order to display the Raspberry Pi / Teensy 3.1 based submersible ROV, I bought a used 3m diameter inflatable pool. This should give us enough space to demonstrate the little buddy.
The ROV got a slight face-lift by adding proper motor-pods and casings for the cables. The ballast stones tied to the bottom got replaced by a rusty old chain in casings. Better solution pending …
For the Maker Faire coming to Trondheim later this month, I’m currently building a simple submersible remotely operated vehicle. The concept is based on a plumbing tube used for the housing and submersible electric pumps as motors. A Raspberry Pi with Camera Module will deliver the live video feed via ethernet cable. The remote control is managed via a serial link to a Teensy 3.1 with sensors and motor controllers. The communication will be implemented using MAVLink, which enables the use of the QGroundControl station.
After initially testing whether the tube could sustain the pressure at up to 12m water depth, pieces are now falling into place. The serial communication via MAVLink works and just needs a little performance tweaking. It can transmit the manual controls from a game-pad down to the ROV controller and the telemetry back up to the ground station. Telemetry data consists of air-pressure and temperature in the body (MPL115A2) as well as orientation data gathered from the IMU/AHRS (MPU-9150). The ground station visualises the temperature and pressure as line-graphs and uses the orientation information for an artificial horizon.
The plumbing tube of the housing is sealed with two acrylic-glass windows. One 6mm one in front of the camera and three 4mm layers in the rear end. The three layers form tunnels for the cables going out to the motors and up to the ground control station. I hope with plenty of silicone this will be water tight.
If anyone has a good idea how to set up a basin/pool to demonstrate the ROV in, let me know.
Four weeks to go! 🙂
The Arduino and the RTC module talk via I2C and the LCD uses a 4bit wide parallel interface. The LCD backlight can be switched between two intensities. It is wired to two Arduino pins at the same time, one directly and the other via a 1k resistor. The LCD draw less then 40mA. As shorting two pins can be rather dangerous for the MCU, the software needs to ensure that the inactive pin is set to high-impedance input mode before the other one is set active.
The initial firmware implements setting the time and manual dimming for the night. As the car-connector also offers a 12V wire indicating when the main-lights are turned on, I could add automatic dimming later on.