Purpose: make a BMW E-series wireless coding/diagnostic cable.
In case of F series, since the cable itself is composed of LAN cable and even the protocol that accepts the signal conforms to the standard of this signal, it is not so difficult to make ENET cable for wireless communication using LAN line. I was able to make the wireless coded cable that I made.
However, in the case of the E-series, called the INPA K+DCAN cable, it was very complicated.
Once the signal received by the computer receives the data using the COM1 port and it also uses the USB cable and the USB port to send and receive signals, it is difficult to modify the signal input method set as the default value in the INPA program. Because it can cause signal loss in lengths of up to 6m or more, it is difficult to solve the problem of wireless, except for the task of wired car and cable with mustard power.
Yesterday, a customer suddenly asked me to diagnose an engine warning light coming up while I was worried. Connect the cable to run the diagnostic program. After curiosity is activated, connect the USB cable between the USB port and the USB port by using the USB terminal – RJ45 LAN terminal <-> RJ45 LAN terminal – I saw. The result is a reliable signal and a faster transfer rate.
After the diagnosis, I came home and started to think about making the following equipment.
As a result, the cable you want to implement is shown in the following picture.
I thought that it would be solved by removing the built-in INPA cable, power input for exporting wireless signal like ipTime, and device for converting USB signal to LAN signal.
I made a decision to make a universal cable that can use both conventional and wired and wireless LAN so that I can use the existing USB cable.
Once the entire system was divided into two parts, the functions of the top and bottom of the case were given different functions.
So it is the bottom plate that I made (BMW scanner v1.4.0 usb interface)
We have already installed the built-in INPA cable and installed the micro USB power input to supply the voltage to the wireless router such as ipTIME that you can use. In the picture, it is not visible on the back, but the 7th pin and the 8th pin are shorted to diagnose and code the old BMW vehicle before 2004, and the switch is attached to enable the diagnosis and the coding of the car after 2004.
And the next picture is the top.
This includes both the RJ45 socket that sends out signals using the LAN line and the two terminals that perform all the functions to send out signals through the USB terminal, which is a conventional INPA cable type, among the devices that transmit the vehicle data. .
Finally, it looks like this:
Now the lower plate and the upper plate are assembled by assembling and have the appearance as the following figure.
There is a toggle switch to cover all BMW new cars placed on the top panel, and the USB signal output, LAN signal output and power output from the bottom left of the picture.
As a result, we succeeded.
The time-consuming part of the above operation was not the soldering quality nor the connection of the circuit, but the work of cutting the shell of the case to a position of the two terminals on the left under the photograph, that is, the RJ45 terminal and the USB terminal.
However, if we can solve the following two problems, we can manufacture a much simpler device and it is possible to commercialize it.
1. Wireless LAN cable connection
At present, it is possible to connect the cable from the cable to the computer as a LAN cable like the BMW F series Enet cable. Now, if you only make it wireless, I think you can provide a convenient wireless working environment like the wireless F series.
The wireless F-series cable accepts signals from the computer itself as a network, so even if you create a wireless network environment, the computer does not have to convert the signal, but the E Series receives the signal through the COM1 port and can not use the computer’s WIFI connection.
2. How to receive and process signals through the COM1 port as network signals
The INPA cable is processing the signal by emulating the USB signal to COM1 from the beginning. If you can get signals received by LAN cable or wireless network as COM1 signal, you can use WIFI signal from all notebooks even if you do not attach RJ45 conversion terminal to your computer’s USB port I think that I can accept and work on it.
Credit: The tutorial is translated from Korean. You are at your risk.