Anything not specifically related to the Speeduino hardware. Eg sensors, bluetooth, displays etc
By bugster_de
Hi folks,

is somebody running bluetooth via HC-05/HC-06 and is able to connect with speeduino via USB?

I do have an HC-06 connected to RX0/TX0. Communication works fine
Then I stop the HC-06 communication in Tunerstudio, plug-in USB and try to connect via USB --> doesn't work
Disconnecting the HC--06 from power and USB works.

The HC-05/06 is pulling the Arduinos RX0 HIGH, as soon as the HC-05/06 is powered up. This is independent if I run it through the level shifter or RX being directly connected. I think this isn't specific to Speeduino but rather a generic Arduino issue. It happens on both my original italian Arduino Mega board as well as the DIY-EFI CORE4 module.

I would want to have both connected in the car: Bluetooth for regular TunerStudio work and using USB for Firmware updates. Removing the ECU from the car is a major PITA hence having both cabled at the same time and connect to the Laptop via one or the the would be a benefit.
I hope somebody has aclever idea here. Thank you!
You need a diode on one of the lines, but I can remember which.
I'm sure its well documented on here and elsewhere.
Do a search :)
By bugster_de
Thank You ! That did the trick! Searching for "Bluetooth Diode" here in the forum brings up the solution. E.g. here:
viewtopic.php?f=14&t=4419&p=47482&hilit ... ode#p47482

In short: a Diode (e.g. 1N4148) needs to be put in the TX line (TX on bluetooth, RX on Arduino) with cathode (negative side, the one with the line) towards the Bluetooth module. It doesn't matter if the diode is on the HV or LV side of a level switcher (I tested it).
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Keep in-mind that the BT connection can do everything a cable can, though perhaps not quite as fast. Tuning, firmware updates, everything, so most have not needed to add the diode or fumble with a cord. Search for how to do FW updates through BT.
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