Toy cars are something that everybody has encountered during the childhood and even a non-car enthusiast like myself has had his share of toy car playing, racing, garage and road building and all that good stuff. You’d think that something like this would be more suited for kids, but what if you’re a grown-up, you have a small car at your disposal AND possess the knowledge to make some cool hardware improvements? That’s right, awesomeness occurs!

This is a DIY project that enhances a Kyosho Mini-Z car with some incredibly useful features: front, rear and under car lights! The model is actually a VW Golf R32 and, as you can see from the picture, it looks terrific, in true Fast and Furious fashion. The lights are LEDs, two white ones for the front, two red ones for the rear and two bars with 4 LEDs for under the car. The circuit keeping them all on uses a NE555 timer that generates a delay and keeps them on regardless of what the car is doing. Other parts include three capacitors, three resistors and three diodes (you can find a complete parts list and detailed schematics in the link provided, as well as other cool pics).

This is a truly astonishing piece of art, soldering a bunch of LEDs on a toy car, especially with the blue under car lights. If you’re a girl, then I suspect this amazing achievement of science might appear… uninteresting. But if that’s the case, then perhaps an LED Heart of Love would be more appropriate.

Mini-car Light Installation: [Link]

Yet another car related project, this is the AVR J1850 VPW Interface which was designed as an On Board Diagnostic tool for car monitoring. The brain of the device is again the ATmega8 AVR microcontroller from Atmel, with 8KB of flash memory (this is more than enough for all kinds of features, since the basic source code is only 3KB).

The device supports serial RS232 for connection with the automobile, different baud rates (varying from 9600 to 115200 Baud), 4 different bus monitor functions and can handle header messages of 1 and 3 Bytes long. The circuit was designed for a single layer PCB and, starting with firmware 1.04, the device has a crystal 7.3728MHz. The controller is programmed using the ISP connector.

The interface has been tested with various ODB software, including Scantool.net, wOBD, Scanmaster and many more. A .pdf file containing the schematic, parts list, bill of material and other information regarding this project is available in the link below, as well as the source code, released under GPL.

AVR J1850 VPW Interface: [Link]

Yesterday I wrote an article about an Atmel based Sony Unilink interface and today it’s another Unilink project, this time based on Becker car radios. For those who do not know, Becker is an important manufacturer of car radios and car navigation devices and it’s based in the UK. Becker made the first car radio, the first microcontroller car radio and the first car radio with CD player and has quite a lot of other achievements.

Becker’s version of the Unilink protocol is very similar with Sony’s in terms of hardware, but different in software. The good thing about this is that you only need a different connector and source code with Becker support. The model presented here is a Becker Monza 7882, a European model, with two DIN-ISO connectors and a Mini-ISO connector field (the picture above illustrates the pinout for this model, you will also find the complete pin listing and additional information).

The MCU used is the ATmega8 from Atmel and the schematics are available for download. The source code was written in C and is also available in the link below (there is a logger only version, an interface version and a modified source code for Becker Mexico 2330). The files are released under GNU General Public License.

Becker Unilink: [Link]

The Sony Unilink protocol is usually meant to control the CD-player of an automobile and can also perform other various tasks. The Sony Unilink protocol can be used to connect other auxiliary devices to your car stereo (these devices vary from CD shuttles to iPods).

This project is an AVR Sony Unilink interface based on the Atmel ATmega8 microcontroller. The MCU runs at 7,3728MHz and the communication with the Unilink bus is made through Serial Peripheral Interface (SPI) and the software supports RS232 input and output. The source code was written in C and the files as well as schematics are available for download under GNU General Public License in the link below.

(Another Unilink interface project entitled GNUnilink, based on the PIC16F628 running at 10MHz is also presented under GNU License).

Atmel based Sony Unilink: [Link]

The idea behind this project was born when a friend asked me too take a look at he’s broken GPS unit (MyGuide 3000) to see if I can fix anything. I started checking various parts like voltage regulators, but found nothing wrong. The gps unit was still not powering up so I checked the cpu, an ARM9 from Samsung and found it broken. Of course I couldn’t do anything about that, because of the BGA package and the bootloader needed after replacing it so the gps unit became a source for parts. The most useful and interesting parts from the GPS were the LCD display and the GPS module.

The GPS module is a RoyalTek RGM-3550LP which has an integrated antenna and is powered by SiRF Star III technology. I immediately connected the gps module to my computer’s serial port(using a max232) to test if it was still working. To my surprise the gps module was working and sending NMEA compliant sentences. Then I had this idea of using the gps module as a navigation system together with a notebook computer, but notebooks don’t have a serial port so I had to use a UART to USB bridge.

The most common used UART-USB bridge is the FT232 manufactured by FTDI which is about $4 which is a fair price because you don’t need any external parts for this chip except some bypass capacitors and that saves you time and money. I never used the chip before but it was really easy to get it working. It even has this custom utility that let’s you program some features saved in the internal EEPROM like the maximum bus power and the product and manufacturer descriptor strings. Anyway these are the only two settings that I tinkered with, but the utility let’s you change some more stuff.

The next thing I had to worry was where to get the power for the GPS unit, because it needs 3.3V and the acquisition current is 50 mA. The FT232 has an internal voltage regulator which provides 3.3 V and 50 mA but I decided not to use that in order to extend it’s life so I ended up using the TPS2148 which is a 3.3V LDO from Texas Instruments. It’s specifically designed for USB peripheral power management, and it’s tiny package(MSOP-8) made it ideally for my application. The TPS2148 handles the current limitation so I didn’t had to worry about that either.

After figuring out the parts I was going to use and the schematic, I had to chose an enclosure for this project. The main target was to get it as small as possible but the limit was the gps module size, I couldn’t of got it smaller then the module . So I went and searched for a plastic enclosure, and I found one just perfect for what I needed, the PP85D from Supertronic. The gps module fits just nicely between the screw channels.

Then after I got the enclosure, I made the pcb using the photo etching technique.. I assembled and tested it, and to my surprise everything worked just fine from the first try. I’m usually not that lucky when I make stuff using new IC’s that I haven’t used before. Sometimes I don’t pay enough attention to the datasheet and I get some small stuff left behind and that messes my entire circuit. Anyway, happy as I was that everything worked from the first try, I put everything inside the enclosure and snapped some pictures of it. As a final note, this was a great project which I enjoyed making, and I really recommend you do something like this if you have a gps unit laying around.

more pictures:

parts list:

• RGM-3550LP gps module x1
• FT232RL x1
• TPS2148 x1
• capacitor 10uF x3
• capacitor 100nF x3
• led x1

schematics and board files were designed in Eagle and can be downloaded here.

Keyless entry has been used for quite some time in automotive industry by most car manufacturers even though such a system may not be in their standard package. The owner receives a card or a small device, much like a remote control, and just by approaching the car, no buttons pushed, the car senses the master and opens its doors.

In this project is presented a method to build your own keyless entry system. Your RFID will be a Nike footpod which will send the secret code to its iPod receiver. This receiver communicates with an Arduino Pro Mini  through an iPod Serial Board. The Arduino listens for the right code from the RFID and gives lock/unlock commands.

You can give these commands to your car’s fob or adapt it to the internal wiring of the door’s lock/unlock mechanism. This can be pretty tricky for there are several systems used for door locking. In some European cars like Volkswagen, Seat, Skoda the command for lock/unlock is given on a single wire. For example if on this wire the computer sees a firm ground then it will unlock if it sees a resistance to ground then it will lock or the other way around. In these case you will need to use diodes or relays.

Asian cars usually have two wires, one for lock one for unlock. You will need negative or ground to control these wires. Things complicate however with the more expensive cars as they use vacuum systems or sophisticated computers inside the door. Usually these cars when equipped with a factory keyless entry system have a sensor behind the door handle that must be triggered in order for the doors to unlock, even if the car senses its owner nearby.

Powering our keyless system requires that you find a permanent 12V supply in your car. Look at fuse box, under the driver’s kick panel behind the steering wheel for thick wires and use a multimeter to measure the voltage. Do not trust thin wires as their 12V can disappear after car’s computer falls asleep. Usually that happens between 15 to 30 minutes after locking the car. Be careful with this because serious damage can be caused.

Other difficulty you can experience, as the project’s author did, is the car’s door locking settings. If you unlock the door but do not open it the car might lock it again after a short period of time. You can change these settings from the car’s computer with a diagnosis tool.

RFID Keyless Entry: [Link]

Here is the schematic of the charger:

After ordering the needed parts I noticed that the  inductor is slightly bigger than I expected it to be, so fitting the board into a small box became a bit of a problem. But I managed to designed the board so that it fits into the chosen box. I also fitted a medium sized TO-220 radiator so the circuit would dissipate the heat even in continuous use of the charger. The pcb was made using the photo etching technique and I tried spraying it with a mix of colophonium and alcohol that would act as a soldermask. The result is not pretty but I hope it will protect my board from corrosion.

After the soldermask dried it was only a matter of minutes until I assembled and tested it. The charger works great, the output voltage remains constant over continuous variations of the input voltage. Now all I have to do is close the box, solder a cigar lighter connector and pack it into my arm rest compartment.

This project was send to us by Bob Ashlock, who is rightfully proud of his achievement, he made a temperature gauge with the LM34 sensor and PIC16F684. He inspired he’s project from this PIC16F84 thermometer that was posted here on youritronics. The sensor has 10mV/F output, not to be mistaken with the LM35 which has 10mV/C output, but the firmware can be easily adapted.

The source code  is well documented, but there is room for optimization, yet taking into consideration that this is Bob’s first project and he learned by himself its a great code. The outcome looks very nice and has its practical use, he used to measure the air and oil temperature in his 66′ Porsche. In the download you have the schematic and source code written in C.

Great job, and thanks for sharing with us your project and experience.

Car temperature gauge: [download]

If you have an old car, and you want to measure the fuel consumption to adjust your driver technique then check out this device. It is build around one Arduino board, off course the project is open hardware like any other Arduino project, the LCD is a simple two row alphanumeric display, nothing fancy about it. To power up, just tap into the battery, connect it anywhere you can find +12V.

The device only works on cars with injector based fuel distribution, by counting the pulses and the time which the injector valves are open, and using a calibration table it computes the fuel burned by the engine, the device has also a menu to access some settings, you can even display the CPU usage in %.

With a little work you could also integrated it into the dashboard, probably won’t increase your old cars value, but it will look good and its a great DIY project.

Fuel consumption calculator: [Link]

The Gas Guzzler Meter is an attempt at putting an immediate dollar value on your current driving techniques: a digital meter that displays exactly what you’re spending as you motor along. Stomp on the pedal and see the bucks zoom out your tailpipe faster than a NASCAR driver competing for the Nextel Cup. This device will help you impress your friends, drive responsibly, and keep those dollars in your pocket.

Gas Guzzler Meter: [Link]