---
title: "BeagleBoard-X15"
description: >-
  The BeagleBoard-X15 is an open hardware single board computer built around
  the TI AM5728. On an LAA it runs from the 12V rail through a flylead MIB.
  The board does not start when power is applied, so the S1 power button has
  to be wired to a virtual button through an opto-coupler.
---

```{include} common-alert-enablement.md
```

The BeagleBoard-X15 is an open hardware single board computer built around
the TI AM5728, a dual Cortex-A15 SoC with 2 GiB of RAM, two gigabit ethernet
ports and eMMC. On an LAA it runs from the 12V rail through a flylead MIB.

The board doesn't start when power is applied. The S1 power button has to be
pressed, and there is no header in parallel with it, so this device-type needs
a small hardware modification.

![Whole setup](/_images/am57xx-beagle-x15-revc/setup-overview.jpg){align=center}

## Components

The following components are required to fully automate the board:

- [Flylead MIB](/hardware/mibs/flylead.md)
- Short RJ45 network cable
- 2.5/5.5mm barrel jack to MIB 2-pin connector, wired center positive
- USB-TTL serial cable with 3.3V logic, for example a PL2303 or an FTDI
  TTL-232R-3V3
- USB-A male to Micro-B male cable, for fastboot recovery (optional)
- Two wires soldered across S1, and a soldering iron to fit them

## Hardware modification

The X15 doesn't power on when 12V is applied. S1 has to be pressed, and the
board exposes no header or pad in parallel with it. Solder one wire to each
contact of S1, the blue tactile switch on the board edge next to the F1 fuse.

Find the two contacts with a multimeter first: the pair that's open at rest
and closes when the button is pressed. Add strain relief, the joints are small
and the wires get pulled every time the board moves.

![S1 with the two soldered wires](/_images/am57xx-beagle-x15-revc/s1-solder.jpg){align=center}

## MIB

### Configuration

No MIB voltage jumper is needed. The USB-TTL cable carries its own 3.3V logic,
so `MIB_Vio` and the `J17` jumper aren't part of this setup.

If you instead use the MIB UART on `J12`, set `J17` to `3v3` and turn the 3v3
rail on, because `MIB_Vio` is fed from the switched 3v3 rail.

### Power

The X15 gets 12V from the `J2` screw terminal on the MIB, out to a 2.5/5.5mm
barrel jack in `P1` on the board, wired center positive.

Then press S1 through virtual button 1. The press must be short: `button 1 on`
immediately followed by `button 1 off`. A held press starts the board and then
powers it off again on release. The press also doesn't register if it lands
within a second or so of the rail coming up, so leave a short delay.

### Serial

Connect the USB-TTL cable to the `P10` header:

| Cable wire | `P10` pin | Signal |
|------------|-----------|--------|
| black      | 1         | GND |
| green      | 4         | board RX, cable transmit |
| white      | 5         | board TX, cable receive |
| red        | -         | 5V, leave unconnected |

The board is powered from `P1`, so the red 5V wire stays off.

![Serial cable on the P10 header](/_images/am57xx-beagle-x15-revc/serial-p10.jpg){align=center}

Plug the cable into LAA USB `Port2`. The console comes up as `ttyUSB0` at
115200 8N1 on port 2010. Turn the port on with `laacli usb 2 on` and leave it
on, the device node disappears with the port.

### Network

Connect one of the two stacked RJ45 ports on `P5` to the LAA private network
interface.

```{admonition} Only one of the two ports works
:class: warning
U-Boot brings up a single interface, `eth2` on `ethernet@48484000`. The other
port never links. If you pick the wrong one you get
`Waiting for PHY auto negotiation to complete... TIMEOUT !` on every boot
attempt and the boot takes minutes instead of seconds.

When it is right you get `link up on port 0, speed 1000, full duplex` and the
board is given `198.18.0.2` by the LAA.
```

![Ethernet cable in the working port](/_images/am57xx-beagle-x15-revc/ethernet.jpg){align=center}

### Recovery

Connect the X15 micro-USB port to LAA USB `Port3` with a data cable. The board
enumerates as a TI USB download gadget, `0451:d022`. Turn the port on with
`laacli usb 3 on` when you need fastboot.

It's not needed to reach the bootloader.