CC1000

A Low Power Embedded Linux system


Manual v 0.3

4MB CC1000
with MMC/SDcard piggyback
8MB CC1000
with DC-DC converter


This manual is a subset of the CC1000 project information on PA3HDF's website. Updated and/or more information might be available.

Content:

Getting started

To get started connect a power supply, connect the console port of the CC1000 to a terminal or a PC with a terminal emulator with the speed set to 9600 bps and connect the Ethernet port to your hub.
If you choose to use the DC-DC converter the power supply should deliver something between 35V and 75V. If you do not use the DC-DC converter connect a 15V @ 0.5A supply. In both cases mind the polarity, a protection diode does not hurt.

After applying power abort the boot sequence by hitting a key. Now have a look at the preconfigured environment settings with the 'printenv' command. The default IP address of the CC1000 is 192.168.0.100. You can change is to e.g. 10.0.0.100 with the 'setenv' command: 
=> setenv ipaddr 10.0.0.100
Use 'setenv' to change other settings if needed. Save the new settings to flash with: 
=> saveenv
Now restart with 'boot' or simply push the reset button next to the console connector.

After a while you will have a running Linux system with a shell attached to the console port.

Modifying startup

At startup the CC1000 executes /etc/rc.sysinit. If you do not have a configured data partion the CC1000 does some basic initialisations and after that starts an HTTP server.
Both the 4MB and 8MB flash versions of the CC1000 have the possibility to add a SDcard. The 8MB version also has a 4MB JFFS2 partion which is used for a data partition. The data partition is mounted on /u02 (old versions may use /data instead). /etc/rc.sysinit tries to mount /u02 and if it finds a second startup script, /u02/etc/rc.sysinit, this script is executed.

Mounting the data partition is configurable with the U-Boot environment variable 'mountcmd'. The 4MB CC1000 has a dummy mountcmd, the default for a 8MB CC1000 is 
	setenv mountcmd mount -t jffs2 /dev/mtdblock0 /u02
For a SDcard you might want to use something like 
	setenv mountcmd mount -t ext2 /dev/mmca1 /u02
Do not forget to update the environmnet with 'saveenv'.

Example /u02/etc/rc.sysinit: 
        #!/bin/sh

        # Services
        /usr/sbin/httpd -h /u02/www
        /usr/sbin/bftpd -d -c /u02/etc/bftpd.conf
        /usr/bin/rsync --daemon --config=/u02/etc/rsyncd.conf --address=192.168.0.100
        /usr/sbin/dropbear -d /u02/etc/dropbear_dss_host_key -r /u02/etc/dropbear_rsa_host_key
Do not forget the 'chmod +x /u02/etc/rc.sysinit'.

The HTTP server is started with another DocumentRoot.
Starting a FTP server is not really needed, because dropbear also supports scp.
If you choose to update your data, e.g. your website, with RSYNC and you have to use the RSYNC protocol, RSYNC should be started.
Dropbear is a sshd server with a low memory profile. If you use it in combination with RSYNC, the standard RSYNC configuration, there is no need to start RSYNC.

Dropbear expects host keys. Generate these with: 
        cd /u02/etc
        dropbearkey -t rsa -f dropbear_rsa_host_key
        dropbearkey -t dss -f dropbear_dss_host_key

The CC1000 comes with a passwd file. The 'root' and 'user' accounts have password 'cc1000'. To change this a new passwd file should be written to /ramdisk/etc/passwd during startup.

Hardware

The CC1000 consists of a main PCB, a frontpanel PCB and a DC-DC converter. The main PCB has:
The frontpanel PCB contains several connectors, of which only the Ethernet (RJ45) and serial port connector (DB-9) are usefull.
The DC-DC converter delivers 15V at 1.3 Amps from an input voltage of 36 - 75V.

Main PCB

[cc1000_pcb.png]

Connector J802

Pin 1 +5V Pin 26 ?
Pin 2 ? Pin 25 ?
Pin 3 PortD_14 / MMC_DI Pin 24 SMCRX2
Pin 4 +3.3V Pin 23 ?
Pin 5 GND Pin 22 ?
Pin 6 Vin LM2940 Pin 21 ?
Pin 7 GND Pin 20 PortC_6
Pin 8 PortD_15 / MMC_DO Pin 19 PortD_6 / MMC_CLK
Pin 9 ? Pin 18 PortC_5
Pin 10 ? Pin 17 SMCTX2, Remark 1
Pin 11 ? Pin 16 ?
Pin 12 ? Pin 15 ?
Pin 13 PortD_10 / MMC_CS Pin 14 ?

Remarks:
1) Remove U801 and connect pads U805-5 and U801-8 to get SMCTX2 on pin 17.

Switch S900

S900 is connected to PortC_7.

Memory layout



Address range Usage
0x00000000-0x0003ffff Base RAM
0x00400000-0x007fffff Piggyback RAM
0xff800000-0xffbfffff Flash, data partition (8MB version only)
0xffc00000-0xffefffff Flash, root filesystem
0xfff00000-0xfff1ffff U-Boot
0xfff20000-0xfff3ffff U-Boot Environment (4KB used)
0xfff40000-0xffffffff Kernel

Software

The CC1000 uses U-Boot and a Linux 2.4 kernel from the The DENX U-Boot and Linux Guide (DULG).
The U-Boot manual is here.

The main user level software is Busybox version 1.8.1 with almost all modules enabled. Besides Busybox the root filesystem (3MB flash) contains:

Development environment

The environment to develop the CC1000 software is the Embedded Linux Development Kit version 4.1 from Denx Gmbh. See the Denx website for full information of the ELDK.

The ELDK gives you a full development environmnet except a debugger (GDB). The main website contains information on how to build a debugger youtselves.

Hardware modifications

Console cable

A RS232 adapter cable needs less space then the front panel PCB.

2 adapter cables.
A RJ45 <> DB9 adapter with a straight cable (left)
A RJ45 cable soldered directly to a DB9 connector (right)

The RJ45 console connector of the CC1000 is compatible with the Yost serial device wiring

Yost DB9 to RJ45 serial DTE adapter wiring

Yost DB9 to RJ45 serial DTE adapter wiring

RJ45 Function Color DB9 Remark
1 CTS Blue 8 Connected, not used
2 CD Orange 1 Connected, not used
3 Rx Black 2 Connected, used
4 SG Red 5 Connected, used
5 SG Green 5 Not connected
6 Tx Yellow 3 Connected, used
7 DTR Brown 4 Connected, not used
8 RTS White 7 Connected, not used

A DB-9 <> RJ45 cable connections:

DB-9 RJ45 MAX3232

Front view
2 3 3
3 6 4
5 4 2

Check your cable with an ohm-meter between the MAX3232 and DB9 connector.

MMC/SDcard interface

4 signals of IO Port D of the MPC823 are available on the J802 connector. These signals are used for a MMC/SD interface.

Piggyback front view Piggyback back view

The 4MB version of the CC1000 has a pin header on connector J802. This header is a suitable mounting point for a piggyback with a MMC/SDcard connector and the second serial port. The 8MB CC1000 does not have this pin header. Use wires to connect the MMC/SDcard connector.

[cc1000_mmc_sd.png] [mmc_sd_contacts.jpg]


MMC/SD signal MMC/SD connector Port D signal Port D mask J802 connector
CS 1 PD10 0x0020 13
DI 2 PD14 0x0002 3
GND 3 - - 5
Vcc (3.3V) 4 - - 4
CLK 5 PD06 0x0200 19
GND 6 - - 5
DO 7 PD15 0x0001 8

The installed kernel has a MMC/SD device driver that uses the SPI mode.
Transfer speed reading: approx. 275 KB/sec.
Transfer speed writing: approx. 133 KB/sec.

Alternative connectors are an old floppy disk connector or an ISA bus connector (use the small one). Do not insert the card too far into a floppy or ISA connector, the card won't make contact.

Second serial port

The TxD and RxD lines of SMC2 are on J802. Connecting a RS232 level convertor (MAX232, MAX202 etc.) gives the CC1000 a second serial port.

[cc1000_serial2.png]

The piggyback has enough room for this. If you do not use a piggyback board, use wires to connect the port to J802.

Remarks: