120 lines
3.6 KiB
Plaintext
120 lines
3.6 KiB
Plaintext
[[hardware]]
|
|
== icE1usb Hardware
|
|
|
|
The icE1usb Hardware consists of a single circuit board (in an optional
|
|
enclosure).
|
|
|
|
It's main building blocks are:
|
|
|
|
* an iCE40 FPGA
|
|
* Two E1 line interface (transformers, biasing networks and ESD protection) footnote:[Second interface requires firmware >= 0.2 and OHCI/OHCI/EHCI host controller]
|
|
* a GPS receiver module with 1PPS output to the FPGA footnote:[Requires firmware >= 0.2]
|
|
|
|
=== Schematics
|
|
|
|
As icE1usb is an OSHW (Open Source Hardware) project, the full schematics
|
|
and design files are publicly available.
|
|
|
|
The design files in KiCAD formwa are available at https://git.osmocom.org/osmo-e1-hardware/tree/hardware/icE1usb
|
|
|
|
PDF rendered schematics are available at https://git.osmocom.org/osmo-e1-hardware/plain/hardware/icE1usb/r1.0/icE1usb.pdf
|
|
|
|
=== Connectors
|
|
|
|
==== X5A and X5B: E1 Interface Connectors
|
|
|
|
On one side of the PCB there are two RJ45 connectors next to each other.
|
|
|
|
Those are the two E1 line interfaces. The interfaces are of symmetric
|
|
120 Ohms type.
|
|
|
|
Assuming the board is oriented with the tab of the RJ45 connectors facing
|
|
up:
|
|
|
|
* Interface 0 is on the right side
|
|
* Interface 1 is on the left side (next to the button)
|
|
|
|
The pin-out of the connectors can be swapped between TE and NT mode using
|
|
the J4 and J5 jumper blocks on the circuit board.
|
|
|
|
A GSM BTS typically implements TE pin-out, while the icE1usb should then
|
|
use NT mode pin-out if no cross-over cable is used.
|
|
|
|
.Pin-out of RJ45 E1 connectors
|
|
[options="header"]
|
|
|===
|
|
| Pin | Function (TE) | Function (NT Mode)
|
|
| 1 | Rx | Tx
|
|
| 2 | Rx | Tx
|
|
| 3 | not used | not used
|
|
| 4 | Tx | Rx
|
|
| 5 | Tx | Rx
|
|
| 7 | not used | not used
|
|
| 8 | not used | not used
|
|
|===
|
|
|
|
NOTE: E1 cables use RJ45 like Ethernet, but Ethernet cables have a
|
|
different pin-out. Particularly, you cannot use an Ethernet cross-over
|
|
cable as an E1 cross-over!
|
|
|
|
==== X4: USB Connector
|
|
|
|
The USB connector is a USB Type C connector. However, it only carries
|
|
USB 1.1 full-speed signals. 5V DC power is also sourced from this
|
|
connector.
|
|
|
|
==== X2: Serial Console Connector
|
|
|
|
The serial console is used for development and debugging. It uses an
|
|
Osmocom-style 2.5mm stereo TRS jack.
|
|
|
|
The serial console uses 3.3V CMOS logic levels
|
|
|
|
The serial console uses a rate of 1000000 bps.
|
|
|
|
The pin-out is as follows:
|
|
|
|
* Tip: Tx output from PC (Rx input of icE1usb)
|
|
* Ring: Rx input of PC (Tx output of icE1usb)
|
|
* Shield: GND
|
|
|
|
A compatible cable can be sourced from the sysmocom web-shop at
|
|
http://shop.sysmocom.de/.
|
|
|
|
==== X1: GPS Antenna Connector
|
|
|
|
The GPS antenna connector is a female SMA connector.
|
|
|
|
You can connect most standard active GPS antennas with built-in LNA.
|
|
|
|
icE1us provide phantom voltage.
|
|
|
|
The use of a GPS antenna is only required when you need a high precision
|
|
clock reference for the 2.048 MHz E1 bit clock, e.g. to provide a clock
|
|
reference to a cellular base station on the A-bis interface.
|
|
|
|
==== X3: GPIO / Extension Connector
|
|
|
|
This is a RJ45 connector adjacent to the USB connector.
|
|
|
|
It is currently unused and reserved for future use.
|
|
|
|
|
|
[[hw-pushbutton]]
|
|
=== Pushbutton
|
|
|
|
This is a push-button next to the _E1 interface '1'_. It is recessed
|
|
to protect against accidental use. You will need to use a paper clip,
|
|
pen tip or other similar object to push it.
|
|
|
|
The button can be used to force booting into the DFU loader in order to
|
|
recover from a broken firmware installation.
|
|
|
|
|
|
=== Multi-Color LED
|
|
|
|
Above the USB-C connector, there is a multi-color RGB LED.
|
|
|
|
This LED is used by the firmware to indicate a variety of status
|
|
information. Pleas see the firmware documentation in <<firmware>>.
|