Tronsmart USB C to Micro USB Adapter has spec compliant CC termination! A fine little adapter for your old USB A-to-MicroUSBs
Full disclosure : Tronsmart directly sent me a set of their adapters to evaulate last month. This is why I do not have a Verified Purchaser tag.
By Benson Leung on January 19, 2016
Benson here again, continuing my reviews of USB Type-C legacy cables, adapters, and accessories. Today I am reviewing "USB C to Micro USB Adapter Convert Connector" by Tronsmart.
Let's check spec compliance :
I'm using my trusty Chromebook Pixel 2015 with the Chromium Twinkie USB-PD Sniffer, available on Amazon from Plugable : [[ASIN:B015X29HLM Plugable USB 3.1 Type-C (USB-C) Power Delivery Sniffer]]
For my first test, I've got the Tronsmart MicroUSB Adapter plugged into a good quality (itself capable of >2.4A) Micro-B cable from Belkin. (this one: [[ASIN:B00WJSPW8Q Belkin 6-Foot 2.0 USB Type C (USB-C) to Micro USB Charge Cable, USB-C Certified]]) . That is then plugged Apple proprietary MacBook charger capable of 5.2V at 2.4A.
The Type-C end is plugged into Twinkie, acting as a pass through to Chromebook Pixel 2015. Picture attached!
First let's run the ectool command from Pixel's command line to check what Pixel thinks is happening on its USB-C ports :
localhost ~ # ectool --dev 1 usbpdpower
Port 0: SNK Charger Proprietary 4681mV / 2400mA, max 5000mV / 2400mA / 12000mW
Port 1: SRC
So far so good. Pixel identifies the charger as a Proprietary type adapter, and has negotiated 2.4A.
Let's see what Twinkie (the USB PD sniffer) says :
> tw cc
CC1 = 18 mV ; CC2 = 420 mV
The tw cc command reads the current voltage values from the CC pins. As you can see here, CC2 pin has a value of 420mV. Referring to the USB Type-C Specification Table 4-25 Voltage on Sink CC pins, this voltage falls right in the middle of the range allowed for vRd-USB, meaning that yes, this MicroUSB adapter has the correct 56k' pullup resistor!
For a HighSpeed USB 2.0 data test, I’ve hooked my Nexus 5X to my Chromebook Pixel via the Tronsmart MicroUSB adapter + Belkin MicroUSB cable to test large file transfer via MTP. It just works, no problem!
Now for more subjective judgments of this adapter : The adapter is a little bit larger than other MicroB adapters that I've reviewed, but it is still compact enough to fit in the opening left around my SUPCASE Unicorn Beetle case for my Nexus 5X. The Type-C plug on this adapter is a stamped metal part that's been wrapped around to the shape of the plug. It does have a seam on one side. Overall, good, but not great, quality here.
The Tronsmart adapter I've reviewed comes in a two pack, which is a pretty good value!
In conclusion : A high quality charging and data sync MicroUSB Adapter from Tronsmart! The adapter is a great safe way to breathe new life into your old A-to-MicroUSB cables for use with newer USB Type-C devices such as Nexus 6P/5X or Pixel devices. It is also future proof for fast charging USB Type-C devices to come!