FREE - RC Heli Optical Tachometer DIY

[Finless]

OK Helifreak user mikef had posted about this home made optical tach some time ago. Many asked for plans and instructions for how to make one. Mike has now made that available for download here on Helifreak.

I myself have not built this myself but looking at the plans / design it looks very sound. It works just like many RC Heli tachs where you look through a view finder and adjust until you see the blades stop. This is a PROPER heli tach design not a airplane prop tach design.

Mike agreed to answer any questions you all have on the design or building it.

Thanks Mike! You Rock!

Here is the link to download the plans and code.

NEW FILE UPDATED 6/6/2008
Download Link -> RC Heli Tach (1 Megs)


Bob

[TheBum]

I agree that the concept is sound and, being an EE by degree and a software engineer by trade, I don't see any glaring errors. It's pretty ambitious, though, meaning that I probably couldn't make the time to build one.

[HFG]

Nice idea ! BTW i doubt many people have or have access to a PIC programmer however i have found an easy and CHEAP solution. RCD PIC programmer (Google it) only uses passive parts and costs about $10 to make. Here is the one i throw together (yes iam aware its very ugly but it works).

[LITHIUMSTATIC]

[HELINHAWAII]

Would Mike or anyone else be willing to pre-program the PIC Micro Chip and mail out to us Freakers? For a fee of course...say $8-12 with chip and shipping.

I would really like to build one of these as I'm always looking for a project. However, buying a programmer seems to kill the cost benefit of buying a tach outright. Plus, I have no use for the programmer afterwards.

[TheBum]

Originally Posted by HFG

BTW i doubt many people have or have access to a PIC programmer however i have found an easy and CHEAP solution. RCD PIC programmer (Google it) only uses passive parts and costs about $10 to make. Here is the one i throw together (yes iam aware its very ugly but it works).

Is this it? It looks like the parts count is about the same. I agree with your $10 assessment.

http://feng3.cool.ne.jp/en/rcd.html

[HELINHAWAII]

Originally Posted by HFG

Nice idea ! BTW i doubt many people have or have access to a PIC programmer however i have found an easy and CHEAP solution. RCD PIC programmer (Google it) only uses passive parts and costs about $10 to make. Here is the one i throw together (yes iam aware its very ugly but it works).

Great idea...but I'm stupid when it comes to any programming type stuff. Is the code for the chip hard to write?

[HFG]

Yes thats the RCD programmer i used. Nice thing about it is that it generates the 12V required to program the PIC directly from the serial port. Jesse there is NO reason to write any code. Inside the files provided by MikeF is a file called TACH.HEX. The hex file is what you program to the PIC.

Programming a PIC is its MAJOR disadvantage for hobby use IMO. This is why i have started using Atmel controllers which you can use USB to program them.

[HELINHAWAII]

Originally Posted by HFG

Yes thats the RCD programmer i used. Nice thing about it is that it generates the 12V required to program the PIC directly from the serial port. Jesse there is NO reason to write any code. Inside the files provided by MikeF is a file called TACH.HEX. The hex file is what you program to the PIC.

Programming a PIC is its MAJOR disadvantage for hobby use IMO. This is why i have started using Atmel controllers which you can use USB to program them.

Ohhhh yeeeaaah, It's still early here in HI and I worked late last night. I got so excited, I didn't look at the rest of the files in the zip. Thanks man! But still, rather than build a programmer too, I'd rather just buy a chip from someone if at all possible...

[mikef]

I would be willing to program the chip for you freaks if you have no way of doing it yourself. You guys buy your own chip and just mail it to me. I would program it for free and you just cover the cost of all shipping. I will test it before I send it back. I would think you could ship this via US postal for $1 or less? How does that sound? You can PM me or email me when you get your chip and I will send you my address. ZIP is 48453 if you guys want to calculate shipping. That $10 programmer looks pretty cool HFG. I might build one just to have an extra programmer around.

I also apologize for the half year it took to get this info out. I get side tracked easily and have multi projects going all the time….. If you guys have trouble with the write-up please let me know. I wrote it from memory and it could have typos (I hope not however). Also if anyone has a suggestion for improvement let me know and I would gladly add it to the write-up. The code I used was just what I came up with and since I am not an expert programmer, there might be a better way. So far the prototype is still working fine. (Rond is the current owner).

Thanks,

Mike