I wanted to share my success using a bluetooth adapter since I have not seen any other posts about using one on this forum. So far I have only tested it with an Android tablet and RealDash. It has been working perfectly. Connection is fast and very reliable. There is no noticeable lag on the dash interface.
There are a few advantages of using Bluetooth over USB for a tablet dash.
1) The usb port on the tablet is freed up to be used for charging (this can also be used to automatically turn the tablet on/off with key power)
2) The usb port on the ECU can be dedicated to the Laptop usb cable for tuning (dash cannot be used simultaneously with laptop, but less plugging/unplugging)
This is assuming that your Link ECU has separate tuning and CANBUS ports.
The Bluetooth Adapter I have been using is one made for Megasquirt MS2/MS3 – PerfectTuning is the manufacturer. https://perfecttuning.net/en/accessories/26-bluetooth-adapter-for-ms2-and-ms3.html
There are a few other BT adapters for megasquirt, they are all likely the same Bluetooth chip and work the same. The Megasquirt uses a DB9 connector for serial connection, so that is what comes with the BT adapter. In order to connect to the Link you will need a Link CAN connector http://dealers.linkecu.com/CANF_2 These connectors need to be soldered and can be somewhat difficult due to their small size. Cable pigtail is also available but fairly expensive.
The following is the pinout on CAN connector, the BT DB9 connector and where those wires need to end up. This can be wired a few different ways. Either the DB9 connector on the BT adapter can be mated to with a female DB9, or it can be cut off and hardwired (or use a different style connector). The two serial wires will go to the CAN connector on the ECU (TX to RX, and vice versa). The 5v and GND wires will need to go to a 5v power source. Do not use the 5v supply from the ECU, the BT adapter can draw up to 30mA. 12V DC to 5V power supplies are very common, it is the same voltage as USB chargers. What I did was buy a USB charger and hardwire a USB cable pigtail to make the connection. I used and like this model:
I recommend powering the 5v power supply from the ACC terminal (radio power) on the ignition switch. This way there is still power to the Bluetooth with the key in position 1 (ignition off). This will allow you to power cycle the ECU without killing power to the Bluetooth adapter – leaving it wirelessly connected to the tablet. This means that the dash will be live in about a second instead of 5-10sec.
In order to use the tuning port to connect a laptop, either the CAN connector must be removed or a 2 pole switch/relay must be put on the serial wires coming from the CAN connector. The switch must be within about 20cm of the ECU, otherwise the serial stream may become active and not allow the laptop to connect. Once the laptop has been connected, the ECU must be restarted to allow the serial stream to become active again. Hopefully in the future this can be changed by Link so that the serial stream is reactivated upon laptop disconnect.
If there is interest and the forum allows, I could possibly make and sell a plug-and-play Bluetooth solution for the Link G4+. Cost would likely be just a little more than the Perfect Tuning adapter.
Here is a video of my dash on a “cold start” – Powered up and connected in less than 10 seconds. Realdash can be set to allow the tablet to sleep when charge power is killed from the tablet. It works well as a OEM style dash and I don’t need to manually touch the tablet at all.
This is what the inside of the PT BT adapter looks like.
Blue = 5v
Orange = GND
Grey = RX
Yellow = TX
h82lose91 got a reaction from Vaughan in Aux4 Output Grounded All The Time
