Bluetooth-RS232 adapter (no USB)

39.10EUR

(Wireless) Bluetooth - RS232 adapter
Mostly used for android VemsDisplay where often it is the only option, but also for PC (Windows XP or newer, or Linux).
Shows up as an RS232 serial port, so can be used for most applications using serial connection. However, there is a limitation (compared to RS232 port): baudrate switching during operation is not supported.
IMPORTANT: +5V (55mA) power MUST be provided via DSUB9/pin9, no USB connector.
  • Triggerlog in 115200 baud is not supported (only lower ~19200, at least when configured to 19200 baud).
  • if using VemsTune, 2013-02-xx or newer version recommended (configured for fix baudrate: so it does not attempt changing baudrate).
  • VEMS ECU fw 1.2.31 or newer recommended. Take care if running older firmware (don't just plug in without checking this; even if it appears to work well): with old fw use AIM mode and connect only ECU => RS232-BT direction (and a 2k7 pulldown between ECU DSUB9female/pin3 and GND for the ECU RX; or better: upgrade firmware) to prevent sending occasional noise-commands (older firmwares supported both new and some older protocols for compatibility, eg. 1.2.27 and before; new firmwares only accept CRC protected commands that prevent accidental data-corruption in presence of noise).

This wireless communications seems to be highly insensitive to noise. (as comparison: the infamous prolific USB-RS232 adapter-cable will warn early - by connection freaking out - if there is significant noise in the system, often due to ignition problems eg. bad sparkplug-connections or insufficient dwell or misfire).
NOTE: bluetooth access (4 digit) PIN-code preconfigured individually per device with AT-commands during manufacturing. (take note of the code, changing the code is possible if someone knows what she is doing, but not supported). Ordercomment "orderpw=AlphanumericpwOfyourchoice" might allow retreival of factory-configured code (if the 4digit PIN code really gets lost, months or years after purchase. The specified alphanumeric code is NOT the 4 digit PIN code, just a reference key to allow lookup, if/when such a web-interface is supported). Take care of PIN (write PIN on device) there is absolutely no supported way to recover.
Your notebook/PC probably has builtin bluetooth, otherwise USB-Bluetooth adapter might be an option.

Options for +5V power-supply. Important:

  • the ONLY way to supply +5V is the DSUB9/pin9
  • Verify: measure +5V on DSUB9/pin9 or if the ECU paper says "RS232 is ready for wifi / bluetooth" (common with motronic55 ECUs).

  • Permanently connected, Wired-in 12V power supply The powersupply (5V regulator) is connected to GND and +12V with wire/terminals (not cigarette lighter plug). DSUB9/pin9 = 5V supply for the adapter.
  • Cigarlighter 12V=> +5V to RS232 DSUB9/pin9
  • powersupply not included (powered from ECU EC36/pin28 or existing +5V supply) via RS232-DSUB9/pin9

Available Options