ecmspy wireless schmatic

[chief_of_smoke]

ok will do.

[HammerBuell]

Ok so a little update on my DIY.

Put everything together, connected to the bike and all was well.... for about five minutes, then started getting intermittent communication issues, then lost the connection and never got it back. Right away I knew the issue, the Tx/Rx lines of the module (specifically the Rx) must have been overloaded by the 5v on the ecm's data lines.



I messaged the fine people at MDFly, through Ebay, told them how I bought their module because it specified 5v operation, and asked them what the operating voltage on the Rx/Tx lines should be, to which they replied

"3.3v, though they work on 5v MCU's (most) your ECM's 5v must have been too much. We will send you another, please step down your Rx/Tx to 3.3v" Really good of them to do that tbh

So I decided to add a resistor voltage divider circuit to what I had already built and just make sure it stepped down to the 3.3v required while I wait for the new module,



As it stands I am going to wait until I have it working well for a week or 2 before I post the DIY. It sucks that the module was not actually 5v on the data lines as they advertised, but that is the norm on all these cheap Ebay so I should have known, but I really wanted to keep it as simple as possible.

Unfortunately the Rx for sure will have to be stepped down with a resistor voltage divider circuit which in itself is not that complicated, it just adds 2 more parts and more soldering and planning for your board. The good news is the DIY will now be for 3.3v modules which should allow you to buy any of the cheap Ebay options.

I put together a quick little diagram for those who are interested



A few notes on that diagram, first if your module specifies 3.3v supply voltage you will NEED a 3.3v voltage regulator. Second, position of the 10k and 20k resistor's does matter, don't get them backwards or the voltage will not step down as intended.

[Loki]

Here is the older how-to
http://www.buellxb.com/Buell-XB-Foru...s-ECMSpy-cable

[chief_of_smoke]

i have read the thread. like to see the pictures tivolya had up. so in my guess to mation, the bluesmirf chip aslo had to be stepped down?

[HammerBuell]

Just the 12v supply, which they did with a 5v regulator. I believe the bluesmurf is 5v regulated on the board itself for the data lines.

Loki.. what I'm trying to achieve is a dirt cheap alternative. Total in parts I'm under $35, and once built, if the module gets wet or whatever, $10 and 2 weeks ans you'll be up and running again.

[chief_of_smoke]

i like your conceot hammer

[chief_of_smoke]

i like your conceot hammer

[Blaylock1988]

I think that board's input rating was overstated. the TX and RX pins on my arduino are rated for 5V and i had 0 problems for the 20+ hours i have had that thing plugged into my bike.

[HammerBuell]

Yeah for sure. They are sending me another for free but asking that I step the data lines down to 3.3v.
But in the same sentence telling me I should be fine for 5v... hrrmm

[Blaylock1988]

Hopefully stepping it down won't affect the data stream quality too much.