pcmhacking.net

i havent tested much but this is what the specs are for it.

I figure there will be demand for these.

Hi Holden202T,

great work in building your own kit.

How did the pricing of the BOM work out?

Have you had a play with Arduino, Teensy, STM32 or Pi Pico development boards? They are probably overkill for a speedo healer but having the bootloader and USB connector would make it handy for updating the firmware to add new features.
Could you add a bootloader to the PIC to update firmware via RS-232 or an FTDI cable?

I'm probably overthinking all of that anyway. Keep up the good work.

Nice work

its not the cheapest, all the parts plus pcb works out about $45 which includes the box.

i normally get my parts from Digikey (USA) and they offer free shipping for orders over $60 .... so if you were to want to order one you'd want to get a few other parts to top the order up to $60.

as far as adding new features, i have no interest in that nor the time!

could save a few dollars by not using the screw down terminals, and just solder wires onto the PCB ... just depends what your looking for i guess.

those rotary encoders are expensive too in the scheme of things.

i guess if your doing a conversion and want your speedo accurate for $50 its not bad.

Silicon chip also did a MK3 speedo corrector which doesnt appear to have the rotary encoders. Its in the Sept 2013 edition but i dont have a full copy of the article.

Well based off your info of the date i found the mazagine article

https://archive.org/details/silicon_chi ... ember+2013

from a first quick glance ... there are still two adjustments, but they use a variable resistor instead of the rotary encoders, theres also a different model PIC on it ... multi colour LED .... its definitely a bit neater with the resistor arrays too.
at a guess its a similar size to the one i made to fit into a nice small box.

looks like its also got a jumper for 24v supply.

I think that is the mk3 kit, which we know doesnt work properly for our application. Here are the schematics for the 2 kits side by side. If we could work out whats wrong we might be able to come up with a fix for the Mk3 based jaycar kit.

Looking at it, it looks like Zener diode ZD2 and the 150ohm resistor on RB0 in the mk2 might make a difference to the types of input signal accepted by the pic. I wonder if those two components were added to the Jaycar if they'd come to life.

Interesting, i have a mk1 and it works well on the T5 hall effect sensor. I recall there was an issue, can someone remind me what the problem with the MK3 is?

if anyone has a mk3 they are willing to send us for testing let me know