After having my Nikon D3100 for a couple of years now and getting plenty of use out of it, I thought it was time to update to a newer camera. I mainly wanted one which would do better in low light conditions and had a higher resolution sensor. Other features would be a bonus. In the end I settled with the Nikon D5300. It looks pretty much the same as the D3100 but with a few additional features…

– 24MP sensor vs 14MP on the D3100
– Higher ISO settings available
– 1080p 60fps video capability
– Stereo sound recording
– A pop-out screen which can rotate 360° on one axis
– GPS location and Wifi (for a smartphone app)

It is also compatible with my existing accessories such as batteries and lenses which is great, as it means I don’t have to find replacements for those too which could have got very expensive. That means my existing 55-300mm lense works on it too.

I haven’t had time to do a lot of testing with it but that will come on my next trip to a race track no doubt! Watch this space…

In other news, my Car Auxiliary Power Switcher has been working flawlessly since I rewrote the software on it. It’s been running continuously (bar the few times the power cable got knocked) without crashing, and without false positive turning on and off of the output. Perfect!

I do notice every day when I get in the car though that the LED is flashing red which means that my battery voltage is under 12.4v. The battery isn’t old and isn’t neglected so I wonder if modern cars have a somewhat higher parasitic draw than older cars or systems stay active longer when the engine is turned off. My old car certainly never had it drop below 12.6v (usually stayed higher). I did double check the drain on the power switcher and it was 2mA, not enough to draw it down overnight (or in a week even). No bulbs have been left on either. Oh well, the engine starts just fine every day so I’m not too worried about it.

Next project is another solar charge controller I think, with an upgraded rating and possibly input and output current monitoring. Again, watch this space!

I’ve been using a dashcam for almost a year now and right from the beginning I knew that my cigarette socket was not switched with the key. I’ve been using a device made by my friend John to switch the power on and off automatically based on battery voltage. I finally got around to making my own so I thought I would document it.

Very simply all it does is monitor the battery voltage. When it goes above 13.1v after the engine is started, it switches on. When the engine is turned off and it goes below 13.1v it switches off after a short delay. Simple. It saves the hassle of remembering to plug it in and prevents your battery dying by forgetting to unplug it.

Specs:

• 7v-15v input (circuit will work between 7-30v but output voltage will reflect input)
• Arduino Nano (Atmega 328p) running at 256KHz (cpu-scalar from 16MHz)
• 5v low quiescent current regulator for the Arduino
• Red/green bi-colour status LED
• N Channel MOSFET for switching (under the Arduino Nano board)
• 100k / 22k voltage divider for voltage measurement
• Can switch around 3A happily (MOSFET rated at 25A but does not have adequate cooling, wiring or PCB traces)
• Typical 1.7mA power draw current (output off)

Features:

• Turns the output on if input is above 13.1v
• Turns output off when below input is below 13.1v after 8 second delay
• If voltage goes above 13.1v before turning off the delay will reset and output will remain on
• Steady red LED shows when voltage is below 13.1v and the output is about to turn off
• Steady green LED shows when the output is on and voltage is above 13.1v
• Flashing green LED shows when off to indicate >12.5v battery voltage
• Flashing red LED shows when off to indicate <12.5v battery voltage
• Voltage accuracy is around +/- 0.1v

Component List:

PCB:

• 1x Arduino Nano 16MHz 5v
• 1x 5v Regulator (Texas Instruments LP2950-50LPRE3)
• 2x 100nF Ceramic Capacitors
• 1x 1N4001 Diode
• 1x 100k 1/4w resistor
• 1x 22k 1/4w resistor
• 1x 4.7k 1/4w resistor
• 1x 470R 1/4w resistor
• 1x 3mm bi-colour LED (red/green) (plus SIL socket strip if you wish)

Download:

Download the Circuit Wizard PCB and Source Code (8KB)

So! I went to Le Mans again this year for the 24 hour WEC race and now consider it my ‘main holiday’ each year. It combines camping which I’ve done for many years now, and racing which I’ve grown to enjoy over the last 3 years. I’ve never seen myself as a motorsports fan until I first attended Silverstone 3 years ago when I got my first DSLR camera. The only reason I went was to try out the camera, but it wasn’t long before I was hooked!

Although there are several classes of cars that take part in Le Mans, I primarily follow the LMP1 class and support Audi. I’ve supported Audi from the beginning really for one reason – they’re the only car in the race running with a diesel engine. I’ve enjoyed diesel technology for many years and it’s the only type of car I’ve owned. The torque is immense compared to petrol which is one of the things I like from it, and it’s one of the advantages for Audi when racing too.

Unfortunately, Audi were given a performance break when they first entered a diesel engine into the race which has slowly been taken away from them, so like all the other teams they’re having to find a way to extract more performance from it each season. Compared with a few years ago, these cars now use 30% less fuel per lap! This is all thanks to performance and fuelling tweaks, and the hybrid systems.

There are several types of hybrid system in use. Audi use a flywheel recovery system which uses a motor-generator on the wheels to generate electricity. This then powers another motor-generator connected to a flywheel in a vacuum, which spins up to a very high speed to store the energy. When it’s needed, it reverses the process and deploys it back to the wheels. Porsche, Nissan and Toyota use a similar motor-generator system but instead use supercapacitors or lithium batteries. Toyota use supercapacitors and the rest use lithium batteries. Each have their benefits and downfalls, but Audi seems to have found the best balance over the technologies as they’ve always seemed to excel. That is until this year.

There are 4 energy storage classes to go with the hybrid systems too. It’s a measure of energy that can be captured and deployed per lap and it’s split up into 2, 4, 6 and 8 megajoule classes. Interestingly, each of the 4 classes was used this year. Nissan used 2MJ, Audi used 4MJ, Toyota used 6MJ and Porsche used 8MJ. Naturally the higher the capacity used the more weight you have to carry so the balance has to be just right. Some how, Porsche managed to use all 8MJ effectively and their straight line acceleration is immense, meaning they can take on any car after a corner and get past them. Unfortunately for them, Audi can go quicker through the corners and that’s where they were re-taking positions. Those two differences makes the cars quite evenly matched over a full lap. I do wonder however if Audi will opt for the full 8MJ in 2016 or not. Toyota are switching from supercapacitors to lithium batteries because the supercapacitors just don’t cut it now. They were much slower than Audi and Porsche this year and they’ve pretty much written this season off as data collection and testing because they just can’t keep up.

The technologies used in Le Mans is destined for road cars, so to see that they can benefit so much from this tweaking and the hybrid systems just goes to show how much this sort of racing is worth doing. Whilst hybrids may not work too well on the road (depending on the type of driving you do – around town hybrids excel, on motorways they don’t), they work very well for racing where there are frequent amounts of heavy braking and accelerating where the energy can be used.

I congratulate Porsche for their Le Mans win this year, breaking a very long streak of wins for Audi. After their downfalls last year, Porsche came right back with improvements to their reliability and knocked the socks off all the other teams. Audi may have won Le Mans if it wasn’t for a hybrid system issue in one of their cars which caused it to lose its pole position. But in any case, the race was still very close at the end. A series of circumstances for both teams slowed them down in different ways. Audi just happened to suffer a little more.

Maybe next year Audi will bounce back and regain their title at Le Mans. I’m certainly hopeful!

Le Mans Photo Gallery:

http://www.andrewwhyman.com/gallery.php?load=images%2Fgallery%2F2015-06-13%2C%20Le%20Mans%202015/

A few weeks ago I finished the final version of my 2nd Arduino PWM Charge Controller. I have been working on this since October 2014 on and off when time has permitted. Knowing that I am going to be using the power box soon for camping, I thought it would be a good idea to finish it.

You can see the post I made about version 1 of the charge controller here.

So what’s new?

A lot is new on this version feature wise, so let me list them one by one…

– LCD Display
– Current Sensor
– Voltage Sense Input
– Temperature Sensor
– Lower Power Consumption

LCD Display

I thought long and hard about whether I wanted to put an LCD on this project or not. Ultimately I decided yes because I would be replacing the entire module that runs the existing screen with a new board anyway, so why not combine them?

My biggest concern with this was power consumption. LCD displays are not always known for their low usage, however I was confident I would be able to make this work. I have a lot of experience using the small Nokia style displays which are 80×48 pixels. By all means it is not a large display but it is only monochrome and is LED backlit.

Using the screen on it’s own is less than 1mA when it is not being updated. I don’t know the exact figure, but its pretty negligible. With the LED backlight on, the power consumption depends on the brightness at which you run the LED’s. For this project I run it at 2 different levels depending on whether it is daytime or nighttime.

Daytime gets a higher brightness to combat ambient light a little more easily, whereas nighttime gets a lower brightness as there is little ambient light to worry about.

Current Sensor

The current sensor (ACS712 based) is not required as it is there only as a visual reference (but I could code something into the firmware to make it calculate total power if I wanted to). All this does is show the current power flow from the solar panels to the battery.

Voltage Sense Input

I had issues with voltage sensing on the first version of the charge controller when large currents were passing through the board and the cabling. So on this version I have made an (optional) voltage sense input so that you can run a 3 wire setup. This should reduce any issues with voltage sensing. So far I have not noticed any problem not using it on my own setup, but the option exists should it ever be needed on longer cable runs for example.

Temperature Sensor

Using a DS18B20 DALLAS temperature probe I have put the temperature inside the power box onto the display. Although it is not currently implemented in the firmware, it would be possible to have charge voltage temperature compensation built into the programming.

Lower Power Consumption

The biggest win from re-making this charge controller is that I was able to focus more on power consumption as a major factor. From the beginning I was trying to get it as low as possible. To do this I had to be careful on not only the components I used, but also on the programming and how long some components were left active.

For example:

During the day, the LCD LED backlight runs at a higher brightness, pulling around 3-4mA. At night, the LED is dimmed to reduce power consumption.

The current sensor is active for just a very short fraction of time every second, just long enough to get a reading. The sensor uses 10mA when active, so this was definitely necessary. At night it does not get probed for a reading.

The CPU frequency remains at 2MHz at all times, except when probing the temperature probe in which it returns to 16MHz for less than 1 second. The temperature only gets updated once every 60 seconds during the day and every 4 minutes at night.

The RGB LED showing the status at a quick glance uses a very low PWM output of around 5% duty. As a result the power consumption is very low, though I do not remember the exact amount of current. By not using PWM or using 100% PWM, the LED is unnecessarily bright and that just wastes power. At night, the LED flashes blue every time the CPU wakes up (4 second intervals) just to signal it is still alive and aware it is night time.

Total power consumption when the CPU is in sleep is just 2mA. That’s 3mA lower than the old charge controller when it was in sleep.

Images

Specs

– 255 step PWM power control
– Solar panel and battery voltage aware
– Over/undershoot protection (software)
– Over-voltage (15.0v) protection (software)
– Automatic Bulk (14.5v) and float (13.5v) modes
– Solar panel to battery current display
– Temperature display
– RGB status LED
– LCD backlit display showing battery voltage, solar panel voltage, charge mode, current, watts, temperature and PWM %
– Voltage sense input
– Re-programmable with updated firmware
– 2mA at night, 7mA (15mA peak) during the day power consumption

Circuit Wizard Layout and Arduino Sketch

Download (14KB)

Apologies that there are no components listed for you to make this yourself. I do not have it to hand at the moment but I will update it here if I remember in the future.

I recently had to update my new CGO2 camera for my Blade QX3 350 AP Combo as it refused to work with my Android devices (HTC One M8 and 2013 Nexus 7). It wouldn’t show up in the wifi list so I couldn’t connect to it. This happened on all of my 5.8GHz compatible Android devices even though it claims to be 5.8GHz compatible. A quick firmware update to the latest version seemed to allow it to work. It showed up in the list so I could connect as expected.

Here is the firmware file that I used:

cgo2gb_1.9.01_fps50_firmware.bin (36.8MB)

Here are some older firmware versions if you need them. I have not tested these:

cgo2gb_1.9.00_firmware.bin (36.8MB)
cgo2gb_1.8.02_fps50_firmware.bin (36.8MB)

Update instructions:

Disclaimer: The firmware file is provided as-is. I accept no responsibility if this update process fails in any way.

1. Format a memory card with FAT32 or just remove the contents of your existing card
2. Copy the .bin file to the empty card
3. Put the card into the camera and turn it on
4. The light on the front will begin flashing purple after a few seconds.
5. Do not turn the camera off during the update process or you may brick the camera!
6. It will take a few minutes to update. When the purple light stops flashing and the light is off completely, turn off the camera
7. Remove the memory card and delete the .bin file
8. Put the memory card back into the camera and power it up. It’s now ready for use.

The default wifi password for the CGO2 camera is 1234567890.

You might remember the quadcopter from my last blog that I talked about. Well the inevitable happened and it’s malfunctioned quite badly. The end result was horrible damage to the quadcopter and the gimbal has been smashed to pieces beyond repair (outside of purchasing every piece of it separately). You can see below the damage done to the quadcopter and after that I’ll explain what happened.

I planned on showing a few friends the quadcopter at a gaming event we met up at as they had not seen one properly before. What better reason to get it out, right? It was dark outside so I planned just a quick flight to show them what it could do with the intention of a proper one the next day.

The takeoff was normal, but because it was a quick flight I didn’t turn on the camera. The gimbal was on however because it was still connected to the quad. After takeoff I hovered for a few seconds, then decided to do a quick ascent to show how quickly it can move. After 2-3 seconds I got a low battery warning on the status LED, which is not unusual under full throttle and I’ve had it happen before lots of times. I backed off and descended back down from about 30m to 10m or so. I held a slow descent straight down when suddenly after a few seconds the props seemed to go to idle and the quad flipped upside down. Within 2 seconds it was tumbling along the floor with pieces flying everywhere.

Everyone was looking at me as if to ask “what the hell happened?”. I looked back and said, “I don’t know why that just happened”. It was clearly a malfunction of the quadcopter. Now you might be questioning the low battery warning, but I checked the battery after the incident and it still showed ~4.1v on each of the 3 cells and 12.4v total battery voltage – normal for a pretty full battery. I was in the air for under a minute before the malfunction.

The quadcopter has 4 flight modes, SAFE, AP (Aerial Photography), Agility and Stunt. I can only access the first 3 modes, and only in the 4th mode, stunt, is it possible to make the quadcopter go beyond a banking level of 45 degrees. That means it is not possible for it to flip upside down under normal operation in any of the other 3 modes. My transmitter is not able to access stunt mode, nor would I want to use it because you get zero assistance from the gyro, etc.

The only conclusion I could come to was a malfunction of the quadcopter’s software, however the damage was so severe that I decided not to investigate it much further as it would involve opening the quadcopter to inspect it. Instead I contacted the model shop where I bought the quadcopter and they said they would send it back to the manufacturer under warranty. I am still waiting to hear from them, but it has only been a week so it might be another week or two.

I received a lot of flack from friends who are quadcopter pilots which considering they weren’t there is pretty hypocritical in my opinion. One believed that because I was near a gaming event, the masses of 2.4GHz wifi signals floating around probably caused it. I disagreed because the risk of wifi affecting it is no different there than in any typical housing estate, where I can assure you there are more 2.4GHz signals floating around than this gaming event. Also, the quadcopter has built in failsafes to prevent this type of interference from causing a crash. If it loses contact with the transmitter, it will go into return home mode, or land mode, depending on battery life and distance from the home point. It did neither in this case and simply dropped out of the sky. You also have to remember that there is parity involved in the communication protocol so even bad data should never have caused it.

Now this isn’t the first time it’s crashed. Shortly after I bought the gimbal (around Christmas) it crashed on its first flight (and broke the gimbal I should add) after it would not respond to my input except for throttle. I had two theories. Either it lost GPS signal (as with no direction input it should hold its position – it didn’t do this) or it was a similar malfunction. It has never done it before without the gimbal attached, yet it has crashed twice now with it attached. Of course this isn’t proof I know, but it warrants investigation to see if the gimbal caused interference which might upset the processor or related components.

At the end of the day I’m going to have to trust the manufacturer to find any issues that there might be with it. I hope they find one with it so they can give me a new quadcopter because otherwise it’s going to be pretty expensive to fix. I’m looking at a new case, 4 new propellers and possibly motors. The gimbal was a write-off, I’d have to replace the entire thing (which I’m not prepared to do given the cost and fragility of its cheap plastic framework).

I’ll write another post here when I get the verdict, but until then keep your fingers crossed that they find an issue.

It’s been a while since my last post – I’ve neglected the blog for the first time since I started it a few years ago. I’ve had plenty of things going on but most of it isn’t worth talking about. That said, I have a few projects on the go and have bought a few things since then.

For Christmas, a friend bought me a dashcam. One of the functions of it is that it powers up and starts recording on its own when you start the car. Unfortunately it only does this if your cigarette lighter socket is turned on and off with the key. Annoyingly, mine isn’t and it’s permanent live. When discussing with a friend months ago we came up with the idea of making something that would turn it on and off based on battery voltage, so he went ahead and made one. It works great, but now I’m in need of the same thing so I’m making my own variation too. I’ll probably make a full post about it when it’s done, I’m just waiting for a few parts to complete it such as a project box and an Arduino Nano chip to run it.

My second version of the PWM charge controller is going to be built at some point too. I realised how much power the USB version of the Arduino Nano was really using compared to how low I could get it, so I’m building another version to replace it with a non-USB Nano board. That way I can reduce the power consumption to 0.5mA when asleep during the night instead of the 4mA or so that it uses now. That 4mA uses a lot of power and is especially noticable now that it is winter and the day time solar is already very low. The charge it takes out isn’t being put back in again during the day and it’s power consumption during the day is higher too, so eventually it would end up killing the battery if left alone. I’ll be experimenting a bit more with the processor speed vs power consumption as well since it doesn’t need a massive amount of processing power to do what it is doing. If it’s running too quickly then it’s just wasting power.

Since my last post I have also bought myself a Quadcopter, or a drone as they are sometimes known. It’s a Blade QX2 350 and is packed full of features. It has a GPS hold function which means it’s incredibly easy to fly and almost impossible to crash into the floor at speed. This function is also known as aerial photography mode as it’s very stable and smooth in operation. I also bought a camera for it which is an SJ4000 and looks just like a GoPro albeit slightly larger. It’s comparable in quality to the cheaper GoPro too and much cheaper. It’s a Chinese knockoff style camera but it works well enough and because it was cheap I don’t mind if it gets knocked around a bit. To go with the camera I also bought a 2 axis electronic stabilised gimbal (which I proceeded to break on its first flight due to a fly-away crash) and it works incredibly well (I’ve fixed it now to the tune of £22 for new casing). It looks like this year I might be building a Quadcopter too with an FPV (first person video) setup on it. Watch this space, and check out my YouTube channel for on board videos.

Tomorrow I have a new case for my PC arriving, the Corsair Vengeance C70. I’ve needed a new case for a while and since I got an Amazon voucher for Christmas from my dearest mother (thanks Mum!) I put that towards it and paid the rest myself. It will replace the horrible case I have now which was an old desktop style server case with the disk drive bays missing. I’m attending a gaming LAN party later in the year and a new case which looks the part for that will definitely be a bonus. Next on the list will likely be a new graphics card as my HD 7770 1GB is feeling dated already, even though I have only had it a little over a year (or is it two? Time flies so quickly these days…). When you can’t even get 30FPS out of Flight Simulator X on medium graphics, you know it’s dated! I’ll probably make a post on that when and if I get it too.

This year I’ll be attending several WEC racing events again, and a 24 hour Brit Car event too which will be a welcome change. Le Mans of course is still on the cards and my photography skills will be further put to the test at all of these events. I’m getting better each time which you can probably tell if you have seen these events in the gallery. Again, watch this space for updates.

This week I finished my latest Arduino project which was my own PWM (pulse width modulation) solar charge controller. I made this primarily for the power box project as the charge controller in it at the moment is a very dumb one. When it hits a certain voltage it cuts off and doesn’t come back on until a lower voltage. This is useless when charging a battery properly so I decided to make my own that would use PWM. This means it always receives a “maintenance” charge.

Like most of my projects this one has been in the works for some time. It was only this week that I took it from prototype and onto the final production stage.

Main components:

– Arduino Nano board

– 5v Regulator (low quiescent current)

– IRF9520 MOSFET

– 2n3904 Transistor

– RGB LED

– 2x3A Diodes

– 1x1A Diode

– Several Resistors (2x 100k, 2x 22k, 3x 10k, 1x 4.7k, 1x 2.2k)

– 2x Electrolytic Capacitors (minimum 16v, ~470uF)

– 2x Ceramic ~100nF Capacitors

Features/Specs:

– 255 step PWM power control

– Solar panel and battery voltage aware

– Over/undershoot protection (software)

– Over-voltage (15.0v) protection (software)

– Automatic Bulk (14.5v) and float (13.5v) modes

– RGB status LED

– Re-programmable with updated firmware

– 9mA power consumption

I decided to use a pre-built nano board because it minimises wastage if the project does not work or I decide not to continue with it. Those components tend to cost the most and it means I can re-use them and replace them if needed.

I carefully chose the 5v regulator to minimise power use. A standard LM7805 regulator uses 5mA even when not being put under any load. 5mA in this sort of project is quite high and it doesn’t cost much to put in a low quiescent current regulator in its place. This combined with a reduction of the standard 16MHz clock speed to 2MHz using a clock pre-scalar, I have got the power usage down from 40mA to 9mA. I suspect some of the circuitry on the Nano board is using some power (such as the 3.3v regulator) that I couldn’t avoid, otherwise 2MHz should be down in the 4-5mA range. Still, compared to my other charge controller which uses 26mA, this is very good and I’m more than happy with it. In addition to this, I am planning a “firmware” update which further reduces power consumption at night by allowing the CPU to sleep further when there is no incoming power to control. If the Arduino was on its own I could get the power usage down to only microamps but with the additional components I’m not sure yet how low it will go.

The code is of course what really powers this project. Nearly all code was written from scratch by myself (some was copied and tweaked from other projects) and takes into account the need to charge at a higher voltage first (bulk) then change to a lower voltage to float, and also over/undershoot of the voltage target. This means that it is as stable as I can make it with the only limitations being the limited 10bit ADC and 8bit PWM on the Arduino (this makes the voltage readings and control less accurate).

LED status:

Red = Bulk charging (14.5v)

Green = Float charging (13.5v)

Blue = Low or no solar input/Night mode

White = Powering up

Resources:

If you like this project you can download the resources below, although some of the component specs are not listed and it comes as-is without any help, instructions or warranty of any kind.

Version 1.0: Original release.
Download Circuit Wizard Template & Arduino Code (9KB)

Version 1.1: Includes sleep code for night time power savings.
Download Circuit Wizard Template & Arduino Code (12KB)

This project still has to prove itself and I may change the code some more, but hopefully I will put it into good use shortly.

I recently got myself an OLED display off eBay which is arduino compatible. I have never had an OLED screen on any device so I thought I would give one a go to see if they were worth it.

Compared to conventional LCD’s, OLED displays don’t need a backlight as each pixel is in fact a light in itself. This makes them incredibly crisp and bright, and the blacks are actually black instead of very dark grey. Unfortunately the more pixels you use the more power it uses too. You have to balance the purpose of the screen over power consumption.

A regular monochrome LCD would be best suited to battery operated items that have to run long term on one battery or where you simply don’t need to show complex data.

A colour LCD would be best suited to more complex applications where the battery doesn’t have to last long but it has to be functional.

An OLED screen is best suited to low power applications that need better visibility of the display and power consumption needs to be reasonably low.

I wasn’t aware of how small this OLED display was until I got it but I was very impressed (once I got it working!) with the quality. Handily it also uses the same syntax in the Arduino code as the Nokia LCD screen that I used on my power box project. That makes it easy to work with and makes the screens almost interchangeable too (besides resolution differences).

As it stands I had no specific plans for this display but I’m sure I’ll think of something! It’s almost small enough to make into a watch display but unfortunately I doubt I could get the rest of the circuitry small enough to make a watch out of it!

My friend Dave started his new business last year, E2E Technologies Limited, which deals with getting the right IT solution for your business in and around the Wirral area of Cheshire and the general North West area of the UK. They deal with small and large businesses alike and no job is too big or small for them.

E2E Tech has over 15 years experience in the field of IT support so you can be sure your business is in the right hands.

If your business is in the Wirral area and needs some IT support, give them a call and say Andy recommended them!

Their website is www.e2etech.co.uk.

Thanks =)