Similar to this hack, I was fed up with AA batteries and low battery life on the Hobbyking 6ch TX. A little simpler than the above hack, mine was less refined as I soldered a XT60 connector straight to the battery leads. This allowed me to hook up a 2200mah 3S battery, with the lid removed and some velcro. Happy flying (on the cheap)!
Here’s some news on my first multicopter scratch build, aka “The Shuriken”. This is my first multicopter build, and I’m frankly surprised it flies, and flies well! I tried to keep it under $100 USD for the budget-minded maker, but ended up around $150 with all the extra bits.
Bill of materials:
Critique on parts:
I’ve never used a Hawaiian sling before (a spearfishing tool), and thought I’d make one for the next coast trip. It’s made of PVC piping 15mm and 3/8″ surgical tubing. The shafts are 5mm x 900mm high carbon steel with a notch cut into the back like an arrow.
I used zip ties to hold everything together, we’ll see how long they last in the salt water. Make sure you glue the PVC pipe well together!
Inspired by a great snorkeling trip to Jervis Bay, I’ve made a couple pole spears similar to the ones we used to make in California. These are pole spears for spearfishing shallows and sandy reefs.
I was able to find the same green garden poles a the local Bunnings, a nice cheap steel tube wrapped in plastic. They even have little bumps for added grip. Although not the strongest material, it is lightweight, and makes for a very balanced and fast shot. Hit a rock and you may bend the tubing!
We also used bamboo which had the same lightweight characteristics but was a little more resilient to missed shots into the reef. It does split however with time and (ab) use.
- Shaft: Bunnings green garden pole, plastic over steel tube $5.50
- Spear head: Land and Sea spearfishing 5 prong barbed
- Length overall: 2555 mm (~8ft)
- Sling material: 3/8″ black surgical silicone tubing, Clarks Rubber $10/m
- Sling length: 900mm
Here’s my latest light build– three 10w LEDS (two warm white, one royal blue) on a heatsink and fan assembly. It’s getting pretty hot (60 degrees c) at the moment, and I think would be dangerous if the fan failed. The next step is to add a thermal fuse to cut out at about 100 degrees (c) in case the fan gives out on a hot day!
Mounting LEDs to Heatsinks
I’m getting pretty good at mounting high power LEDs to aluminium heatsinks; here’s the procedure:
1) Drill some pilot holes
2) Apply heatsink compound
3) Use small self-tapping screws to attach the LEDs to the heatsink
Make sure you drill holes smaller than your screws!
Controlling a servo motor with an Arduino board and potentiometer. Rotation output to the SerLCD module. Hello, Coke-bot!
28 July 2010
A link to the sister post documenting the hardware configurations I’ve tested for Pachube and Arduino web service data logging. Tests Seeeduino and DFRduino clones with the Official Ethernet Shield and the DFRobot Ethernet Shield.
25 July 2010
Logging the data to the internet, via Pachube feed 8281.
15 June 2010- New improved circuit, better readings
Temperature calculation for voltage of board (vB), analog output (a), voltage divisor (vd), millivolts (mV), kelvin (k) and celcius (c).
vB = 4.955
a = analogOutput
vd = 1024/vB
mV = a/vd
k = mv/10
c = k – 273.15
- Updated Jun 5 ,2010- SerLCD 2.5 and Arduino 0018 Sketches and Video
- Repost from Nov. 28, 2008 on MOFIB.org (transferring for archival purposes)
–> Processing sketch for (standard firmata arduino 0018)
–> Arduino 0018 sketch
–> SerLCD 2.5 with LM335A Arduino 0018 Sketch (do not upload with SerLCD hooked up to TX pin! It may corrupt the module memory.)
Here is a recent experiment I’ve done with making a cheap temperature sensor connected to my MAC. The sensor itself is quite cheap to make (the orange board), the sensor IC is about 3 dollars, and the rest are some wire jumpers, a 2k trim potentiometer and a resistor. Total cost about $8-10 and some free time.
What you see the temperature board hooked up to is an Arduino, a cheap USB i/o controller available from Sparkfun electronics. I can control about 10 analog inputs (one is being used to monitor the voltage of the temperature sensor) and 10 or so 5V outputs that I monitor/switch from the computer. The neat thing about getting this interfaced to an i/o board is I can use the temperature data to switch devices, sound alarms, etc.
Here is a screenshot of the software. Basically, the temperature sensor takes an input of 5v, and will output a voltage at +10 mV/ Kelvin, which can be easily converted to Celcius as seen in the software. The sensor turns out to be quite accurate and highly responsive — I can breath on the sensor lightly and detect a minute temperature change. Right now it is obviously not waterproof, but that is easily solvable with some heat shrink tubing (this is actually recommended in the IC datasheet by the manufacturer for making waterproof temp. sensors!)
Could you post the actual schematic, just so it is more clear, how the connections on the test board were made.
Also, how cheap is Arduino? Do you know if it is available worldwide?
Is there something similar for digital input/output? I see so much potential use for this gizmo it is mind boggling.
Also, do you know, how accurate are the readouts from Arduino?
Andy, the Arduino boards are about $30 USD, I have one I brought from the US from Sparkfun electronics, and I’ve also purchased another one here in Australia (thats why you see two, my temp sensor actually only uses one, but I was playing with getting the two to talk when I took the pictures). They are fairly popular among the physical computing community so you should be able to find them quite easily; if you don’t have any in your country I’m sure you could find an international shipper.
The Arduino board has 13 digital in/out pins that can be used either way, and 6 analog inputs. Each digital pin can also be used for serial TX or RX, and two digital pins are also available for hardware serial TX/RX. Lots more information on these boards is available on the Arduino.cc website. Great little boards and I love them to death.
Your question about accuracy– the accuracy would be as good as your sensor. The temperature sensor I’ve build here depends on the trim pot to make a calibration, which is only as good as the thermometer I’m calibrating to. What I read from my analog input is an integer value from 1-1024, which I’m assuming 1 = 0v and 1024 = 5v in my calculations. I then convert the number to volts, then to kelvin, then to celcius. You can see the original 1-1024 reading as “raw” in my software.
Here is the schematic I used from the LM335Z Temperature Sensor PDF. The trim pot used is actually 5k (10k works, but I found 5k is actually better for the 5V load you get from the Arduino), and the R1 resistor is 2k. Find the LM335z from Mouser or some other electronics supply. I can buy them from my local electronics shop they are that common.