DIY analog servo car instruments

This is an attempt to make analog car instruments using simple materials.

For start I made a speedometer that is driven by a simple 180 degree servo. As the max rotation of the servo was only 180 degrees I decided to gear up its output using some gears that salvaged from an old printer. The ration of the gears is 1:2 that means that the needle can rotate for 360 degrees.

To interface it with the game (liveforspeed) I used my AVR motion controller 1.5 (AMC) and plug it in its first servo port.

In the profiler I assigned the effect #36 that is the speed output to y axis output that sends the data to the first servo port on my AMC. An issue that I have to overcome with the current profiler was that the g-effect output, that can be used to output linear motion, can only send 127 positive positions... So I had to modify the rc servo code on my AMC to assign the 127-255 received values to a full swing of the rc servo. This means reduced resolution but for now it works!

A request to Sirnoname: In your next profiler add linear effects that can have base as 0 (no negative values).

Unfortunately I also realized that liveforspeed plugin doesn't output RPM to be able to also use a second instrument for RPM that I have. I'll try it later with GTR2 probably... Anyone that can make an rnr profile that reads speedometer and RPM from GTR2??? Please?

Here are some pics:









Yes I know, lots of duct tape... :rofl: I'll bolt them down later to a more solid construction.

And of course the video:

http://www.youtube.com/watch?v=ljzpFSOsAvE


Here is the same video with hi-res quality (its recommended to see this instead of the youtube video!!!!):
http://rapidshare.com/files/105035863/servo_car_instrument_AMC1_5.wmv


Enjoy!

Regards, Thanos

Cool :thbup:

You should try to grab a real automotive gauge cluster from the junkyard. With fuel indicator ;D

Regards
Christian

Unfortunately, the gauge clusters from real cars, don't use servos, but electromagnetic coils that follows the voltage given from the measure points. Some of the gauges even use aircore driven gauges, that are even more difficult to drive...

Anyway, simple servos are the easiest way right now for DIY gauge panel for the hobbyist! :thbup:

I've seen that too few downloaded the Hi-resolution video I uploaded on rapidshare... Too bad, you are loosing many details not shown on the youtube video!

Regards, Thanos

I know, but you could use an automotive cluster anyway, and replace all electronics behind the display with your geared servos.

Would be way more eye candy

Regards
Christian

I've looked around for some real car instrument panel to hack but I could not find anything decent.

One surplus store I visited had seperated round-shaped instruments, but their cost was 45 - 55 euro each!!!

Too bad I can't have easy access to car junkyard's here in Greece as in the other countries around the world... ~censored~

So I'll keep making my own I guess. Anywone has photos of instrument plates without the needle?

Regards, Thanos

Hi to all,

I want to explore the possibility to use some of the industrial air-core driver chips to control a real car gauge cluster...

I found several of these that I can interface to microcontroller but I had no luck on online sourcing them.

Here what I found so far:
CS4122 (Triple Air−Core Gauge Driver with Serial Input Bus)
SA5778 (Serial triple gauge driver)
CS4192 (Single Air-Core Gauge Driver with Serial Input Bus)
CS8190 (Precision Air−Core Tach/Speedo Driver with Return to Zero, FREQ_Input) (PDIP−16 package!!!)

If anyone finds a good online source for them (preferably with paypal payment) please post it here. Also I'd like to know if there are other chip solutions I have missed...

Best Regards, Thanos

Hello Thanos, your AVR has 4 outlets for servo, I have a question,
if I use two Servo RC for RPM and Speed as your bundles, I need to potentiometer feedbaak of position or do not need?
two outputs exits would be free for 2 engines more?

One AVR can control RPM + Speed + wiper motor lateral inclination and another engine for acceleration, total 4 axes?
or should I use AVR to control RPM and Speed and other independent AVR for movements SIMBIKE two or trhee axis?



Thanks
Monast

In case of RC servos, you simply connect them directly to the AMC1.5 servo ports. No pots are needed at all.


Regards
Christian

Hi Monast,

Now that I got Profiler2 USO working fine, I will program more axis into a single AMC. I will program definitely 4 axis and perhaps 4 more axis to be able to drive simple servos for instruments. Just be patience a little!

If you want to proceed with the old profiler, you will need to use one AMC with firmware v1.0 for the wiper motor lateral inclination and for acceleration, and a second AMC with simple servo firmware to drive the instruments! (I will provide this firmware if necessary later...)

Regards, Thanos

Ok Ego, very easy!!
I've been working on the mechanics of Simbike structure, which is why I was unable to devote more time to the forum, but now that I have the entire structure,and I found the motor-engines I think that it is time to start testing and work to get X Sim-2. I would like to collaborate with you doing tests with my test bike sim soon.
I will work in a plug for Superbikes X-Sim so they can give me the keys for access to X-Sim 2 and I test it.
I think it is better to work with the new Profiler 2 because Profiler 1 is much more complicated X-SIMBIKE project , 2-axis wiper,one neumatics axis, two servo (rpm and speed). I have two AVR 1.5 + 4 DSMH but first need Profiler 2.
What do you think guys ?
You are a Dream Team!!!!!!

Monast

Nice to hear. Why not starting a project thread with some pics of your progress

Regards
Christian

Hi!

I have great news! At last I made the digital speedometer on my AMC to work! I used an I2C chip to drive the signals to the enable 7seg lines and multiplexed their data lines with BCD to 7segment drivers. This is a design not found nowhere else around the internet
(At least I could not find anything similar!)

The hard part was the coding of the multiplexing of the 7seg numbers as I had to figure out a way to separate the speed number into three different digits. For example the number 243 into 2, 4, 3.





The I2C chip has free one more port that I can add to it another 7seg digit, to indicate the GEAR number.

What remains now is to make a prototype of it on a protoboard until I design a proper PCB layout. The best part is that you need only two ports of the AMC to connect the whole circuit and drive four 7seg digits!!!

@Monast
I will send you the protoboard prototype once I assemble it and fix the relative firmware for the AMC to also work with the rest of the analog servo instruments you have!

Best Regards, Thanos :

Thanos You're a genius! is great news, it's fantastic, I am impatient to mount.
I bought a servo HITEC HS-85BB do not know if it is 90 º or 180 º you know what, your fireware it is diferent for 90º or 180º?

I want to use HS-85BB because it is small and fits in the copkit
What use to speed and rpm with its 7-segment LEDs.
:yippiee:
thanks
Monast

This in an update on the progress of the DIY Car Instruments project.

I put side by side the analog (R/C servo driver) gauge and the Digital 7 segment display to see how accurate it is. They retrieve the data from the same variable right now.

http://www.youtube.com/watch?v=7S81fBVMoJg

For better resolution of the video click below and choose Watch in high quality
http://www.youtube.com/watch?v=7S81fBVMoJg

I will put an hyperterminal interface that will allow you to change the settings of the RC servo to fit to any dial size and rotation level. These variables will be available:
-Division factor: To be able to limit the rotation of the servos to 180, 90 or 45 degrees.
-Percent factor: To be able to match the plate dial numbers step distance. From 1% to 50% increase.

The first prototype will be able to move two servos for analog gauges (Speedometer, RPM), and two Four digit 7segment displays. The input data will be 16bit to be able to display up to the number 9999 on the 7Segment digits.

Another idea I have is to add this in the existing AMC firmware, to also have the motion of the 2DOF platform in the same controller, but this will be subject of investigation on how the extra code will affect the processing power of the controller.

Regards, Thanos :

If you disassemble servo and connect shaft with needle to centr cog (like on picture) you got mutch faster movement and bigger range but you lost some accuracy.

@ SirNoName
Are you shure you can positioning this winch servo? I ask'd a guy in a RC Store and he sayd that you can only use this servo's like a DC Motor, not for a clear position. (But he hasen't a winch servo there, so i'm not shure about this what he sayd)

@ Mambo
The range depends on the poti that is mounted in the servo. If you remove the pin then you have not much more range than original. If you get 200 degree is very good. But i ordered yesterday a poti with 300 degree, to mount external. (Normaly they use 5k poti's in servo's) like this it should work. (Already tested with an external 230 degree poti - works fine)

you dont remove anythink, just connect shaft to the gear (so you skip one transmission and that gives you mutch more range)

And also a point of interess is how many degree's did you reach with this modification??
(Normaly the servo has a mechanical stop on max 180 degrees, and the pot make not more than 200 degree, and
is mounted on the last gear...)

Hy Thanos,
How will the project?
You know where I can get my SIM copkit LED BIKE?

Best regards!!

Monast