After queuing in Huaqiangbei electronics market for an hour, I successfully bought the long-awaited le1. Combined with the previous Nokia tablet N1 and Apple’s new MacBook, I finally collected three types of type-C interface devices: mobile phone, tablet and laptop (can I exchange for top-notch equipment? Mini Compact, positive and negative the same, two-way can be connected; Power supply, audio, video and data transmission can be integrated into one “port”. What does the legendary best interface bring to our consumers on the three devices?
According to the USB type-C standard 1.1 issued by USB if, the three devices are tested preliminarily.
Before testing, first popularize a basic knowledge. There are three standards related to USB type-C physical interface: USB type-C 1.1, USB PD 2.0, battery charging 1.2. If all three protocols are supported, all the advantages of type-C can be realized. Type-C separates the role of device in power supply and data transmission. Power transmission is divided into SRC (i.e. power supplier, e.g. adapter) and SNK (i.e. power receiver, e.g. USB flash disk). Devices that can play both SRC and SNK roles are called DRP devices (such as laptops and mobile phones). Among the DRP devices, there is a kind of devices that are especially inclined to become SRC devices, called try. SRC devices (such as mobile power supply). Data transmission roles are divided into DFP (traditional host) and UFP (traditional device or slave). By default, SRC is DFP and SNK is UFP. If you want to change this default configuration, you need to use USB PD 2.0 communication protocol for role_ SWAP。 All these roles are defined and switched by CC logic chip in USB type-C protocol.
The first test, type-C port CC logic test, through a special type-C cable, we lead out the CC logic pin of MacBook. After oscilloscope test, there is a 50ms square wave on it, which proves that it is a type-C standard DRP device, namely dual role port, which can charge both Mac Book and mobile phone through this port. When charging Mac Book with apple original adapter, the communication waveform of USB PD can be obviously observed on CC pin. After successful communication, the power supply voltage increases from 5V to 14.5V.
The second test is charge discharge test. The first step is to use any 5V adapter and connect the charging adapter line based on ledrui ldr6013 type-C interface chip (type-C protocol and bc1.2 protocol are processed at the same time), which can charge the MacBook smoothly. Under the condition of stable power supply, the maximum charging current is 2.8A. The second step is to use a C port to switch to a female adapter, and use MacBook to charge the iPhone 6 plus, which is very normal. So far, it has been explained that MAC book belongs to DRP device. The third part is to judge whether MacBook belongs to try. SRC device in DRP device. Using try. SRC mobile power supply based on ldr6013 chip to charge MacBook, 100% success. It is proved that MacBook is a DRP device which is not try. SRC (if try. SCR meets try. SRC, the charging direction is random).
The third test, data transmission, using the self-made type-C port to a bus converter, connected to the iPhone, data transmission is normal, after checking the manual and online information, macbook supports usb3.1 GEN1 host, downward compatible with USB 3.0 and USB2.0
Sidelights: during the test, the C port was damaged. Fortunately, within 7 days, the product was exchanged for free. Apple’s after-sales service was quite good. It could be replaced with a brand new machine on the same day.
2、 Music 1
The first test, type-C port CC logic test, after testing, the CC of le1 is a pull-up resistor or a pull-up current source, without scanning waveform. Therefore, it is basically confirmed that it belongs to DFP device, that is to say, in C protocol, it defines itself as an adapter.
The second test is charge discharge test. The first test has already prompted us that le1 is a DFP. In order to verify this problem, we use the original data cable of MacBook to connect le1 with the type-C port of MacBook. A magical thing happened. Le1 is charging MacBook. Well, I admit that le1 really defines itself as an adapter. It can charge the SNK or DRP device of C port. In the second step, we used the MacBook original adapter and the original cable to charge the le1. As a result, there was no response. That’s expected. It’s equivalent to connecting two adapters together. Of course, there is no response. The third step is to charge le1 with the line from lederi port a to port C, and connect any 5V adapter, and the charging current can reach 1.4A smoothly. It shows that le1 can only charge through A-port to C-Port, and can’t connect to the standard C-Port adapter.
The third test is data transmission test. The first step is to connect le1 to Windows computer, and you can recognize a USB flash disk smoothly, which is no different from ordinary Android mobile phone. This shows that it can be used as a USB2.0 device. The second step is to use a C port to switch to a bus adapter, connect a U disk to le1, then you can read the U disk smoothly and play the audio and video files inside, which shows that le1 can be used as a USB 2.0 host.
It is commendable that Apple’s strict compliance with the three standards of USB type-C 1.1, USB PD 2.0 and battery charging 1.2 provides a model for the industry’s type-C interface devices. LETV’s choice is a helpless move, because unlike apple, the boss can play from chip level to finished product level. At the design stage of le1, no type-C interface chip on the market is mass-produced, so we can only go back to the next. If you can use ldr6013 of lederi and support type-C chip of DFP, DRP, try, SRC and UFP, you can have more creative space to play.
In fact, this test also brings another problem. The original intention of type-C standard is to unify the interface and avoid the waste of social resources. However, at this stage, the adapter and connecting line that can charge apple can’t charge le1, while the charging line of le1 can’t charge MacBook (the measured charging current is 500mA, which can’t meet the power supply of MacBook), so is there a solution that has the best of both worlds? The answer is yes. Lederi has designed a connection line scheme from a port to C port, which supports both type-C and BC 1.2. It can charge MacBook and le 1, N1 at the same time, and is compatible with data transmission. Now it has been imported into the mobile power supply industry, and is known as the leader of “everything can’t be charged”, Soon you will see this brand of omnipotent A-port to C-Port charging cable on the market.