Linking two Micro-B devices with a Micro-to-Micro cord
Most Micro-B cords run from a Type-A host to a device, but some tasks need both ends to be Micro-B. A micro USB to micro USB cord links two devices directly, and it is built around a specific purpose rather than everyday charging. This guide explains where that layout is used, how OTG fits in, and why both-end-Micro cords are far less common than the standard host-to-device design.
Quick Answer / Summary
A micro USB to micro USB cord has a Micro-B plug on each end. It is used for device-to-device links, such as moving files between a phone and a camera or connecting a small hub to a portable drive. Both devices usually need OTG support, and one side must be able to act as host. Because host-to-device cords cover most needs, both-end-Micro cords are a niche item with limited lengths.
Where both-end-Micro cords are specified
Some embedded boards ship with a Micro-B port that is meant to link to another Micro-B device rather than to a computer. Development kits and small instruments use this layout when the second device is the power source and the first is a peripheral, or when a service port links two boards in a stack.
In these designs the cord is a fixed accessory, ordered to a set length and kept with the kit. It is not a general-purpose consumer item.
Accessory cables for kits
When a kit lists a Micro-to-Micro cord, the pinout and the length are part of the specification. Replacing it with a host-to-device cord changes which side supplies power and can prevent the pair from working. Order the exact accessory so the two devices keep their host and peripheral roles.
OTG roles in a device-to-device link
OTG decides which device is the host. In a Micro-to-Micro link, one device must present the grounded ID pin behavior that marks it as host, and the other must accept the device role. Not every phone or camera supports OTG, and those that do may limit what they can power.
When both sides try to be host, or neither does, the link never enumerates. Check the OTG support of each device before assuming a Micro-to-Micro cord will work.
Power direction between two Micro-B devices
In a device-to-device link the host side supplies current to the peripheral. If that current exceeds what the host port can deliver, the peripheral may reset during a transfer. Use a self-powered peripheral, or place a powered hub in the middle, to keep the link stable.
Why the design stays niche
The standard host-to-device cord covers nearly every everyday job, and it costs less because it is made in large volume. A both-end-Micro cord serves a narrow set of links, so fewer lengths and gauge options exist. That limited supply is the main reason the design stays niche.
For general use, buy host-to-device cords and keep one or two Micro-to-Micro cords for the kits and instruments that require them. That mix covers both routine charging and the occasional device-to-device link. Keep the two types in labeled bins so a service call does not swap them.
Stocking for mixed fleets
Teams that run both computers and instrument kits should label each cord type and store them apart. A mislabeled Micro-to-Micro cord used as a charger will not power a phone from a wall adapter, and a host-to-device cord will not replace a kit accessory. Clear labeling prevents that mix-up during service calls.
Comparison Table
| Cord layout | Host role | Where used |
|---|---|---|
| A-to-Micro-B | Computer or adapter is host | Charging and sync for most devices |
| Micro-B to Micro-B | One Micro-B device acts as host | Device-to-device links and kit accessories |
| Micro-B to Micro-B with hub | Hub provides host and power | Links beyond host port current |
| Micro-B to Micro-B short | One Micro-B device acts as host | Stacked boards and service ports |
Table: Micro-B to Micro-B compared with host-to-device cords
Practical Application Scenarios
- A development kit ships with a Micro-to-Micro cord that links its service port to a second board.
- A technician links a camera to a phone with a Micro-to-Micro cord to move files in the field.
- A bench kit labels its Micro-to-Micro cord so it is not swapped for a host-to-device cord.
- A portable drive gets its own power so the device-to-device link stays stable during a transfer.
Related Products and Further Reading
- Micro-B cord product list – Compare cord layouts and lengths.
- Ask our cable team – Request help with a device-to-device link.
- adapter and converter guide – Understand how adapters change host and device roles.
- Mini-B extension cord details – Compare the older Mini-B plug with Micro-B.
Frequently Asked Questions
What is a micro USB to micro USB cord used for?
It links two Micro-B devices directly, such as a phone and a camera or a kit board and an instrument. One side must act as host through OTG.
Do both devices need OTG?
The host side must present the grounded ID behavior that marks it as host, and the other side must accept the device role. Check each device OTG support first.
Why are these cords rarer than A-to-Micro-B cords?
Host-to-device cords cover nearly every everyday task and are made in large volume, so both-end-Micro cords serve a narrow set of links with fewer length options.
Can a Micro-to-Micro cord charge a phone?
Not from a wall adapter, because both ends are Micro-B and no Type-A host is present. Use a host-to-device cord for charging and a Micro-to-Micro cord for device links.