VERSION 1.0
J20 (38223)
J20
technical reference manual
38223
Version 1.0
Preliminary
November 2016
Auvidea GmbH
Kellerberg 3
D-86920 Denklingen
Tel: +49 8243 7714 622
info@auvidea.com
www.auvidea.com
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TECHNICAL REFERENCE MANUAL
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VERSION 1.0
J20 (38223)
Copyright Notice
Trademarks
NVIDIA, the NVIDIA logo, CUDA, Jetson, Maxwell,Tegra and VisionWorks are registered trademarks and/or
trademarks of NVIDIA Corporation in the United States and other countries. Other company and product names
may be trademarks of the respective companies with which they are associated.
© Auvidea GmbH 2016
All Rights Reserved
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VERSION 1.0
J20 (38223)
Features
J20 six camera adapter module for the NVIDIA® Jetson
™
TX1 dev kit
The J20 adapter module is specifically designed for the TX1 dev kit. It plugs into the 120 pin CSI-2 camera
socket. Six 2 lane CSI-2 interfaces are provided. The 15 pin CSI-2 connector is compatible to the Raspberry Pi
camera connector. Up to six identical camera modules may be plugged in. To access all 6 cameras individually
3 I2C busses are used. Each bus connects to 2 connectors. To separate the 2 cameras on a single I2C bus, the
2nd connector (J2_x) is connected through an I2C address translation device. This changes the I2C address of
the camera so that 2 cameras can coexist on the same I2C bus.
Software drivers
The J20 is intended for software developers who wish to develop a software driver for setups with multiple
cameras.
• Ridgerun (ridgerun.com) is developing drivers for multiple Raspberry Pi camera setups. Please contact
Ridgerun for details.
• Raytrix (raytrix.de) is developing a driver for their C41 4k CSI-2 camera module. Please contact Raytrix for
details.
Status
Rev 1:
38223
very limited supply
patch for power up reset of GPIO port expander
38223-2
first samples end of November 2016
Rev 2:
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VERSION 1.0
J20 (38223)
I2C configuration
#
1
2
3
4
5
6
port
J1_1
J1_2
J1_3
J2_1
J2_2
J2_3
I2C
device
0
6
2
0
6
2
CSI-2
bus
CSI-A
CSI-C
CSI-E
CSI-B
CSI-D
CSI-F
address
translation
-
-
-
✓
✓
✓
Pi camera 1.3
0x36
0x36
0x36
0x34
0x34
0x34
Pi camera 2.1
0x64
0x64
0x64
0x12
0x12
0x12
B101
0x0F
0x0F
0x0F
0x0D
0x0D
0x0D
Example:
Pi Camera 1.3 plugged into port J1_1 (I2C device 0)
$ i2cdetect -y -r 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00:
--
-- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- 36 -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- UU -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- —
The „36“ is the hex address 0x36 and indicates that no driver is loaded yet. If a driver would have been loaded
it would show as „UU“ in location „36“.
Connecting the cable for the cameras or B101 modules
The cameras are connected with the standard 15 pin FFC cable with 1.0mm pitch. To plug in the cable just lift
the brown hatch of the connector, insert the cable the press the hatch down.
Note: please make sure that the contacts of the FFC cable face down. They have to be on the opposite
side of the brown hatch.
The cable is now safely locked in place. Some cables may have lengthy stiffeners on the opposite side of the
contacts. So it may be difficult to slide the cable in, as the connectors are placed close to each other. In this
case please use scissors to shorten the FFC cable. So contact length of 2mm is fine for the connectors on the
J20 module.
Auvidea supplies FFC cables with contact on the same side in various lengths.
Note: The Pi cameras and the B101 require FFC cables with contacts on the same side.
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VERSION 1.0
J20 (38223)
Initialization
The J20 rev1 requires a supply of 1.8V from the dev kit board. This has to be enabled first by writing to the
GPIO port expander on the dev kit board. Rev 2 of the J20 features an on-board 1.8V LDO, so the enabling of
the 1.8V supply is not required. Please run the following commands every time after powering up the system,
so that the J20 is initialized.
i2cset -f -y 1 0x77 3 0xfb
i2cset -f -y 6 0x20 6 0x3e
- enable 1.8V power to the J20 (rev 1 only)
- configure the outputs of the I2C port expander
(low byte) - clock lines remain input, so there
is no data collision
- configure the outputs of the I2C port expander
(high byte)
- write ones to all GPIO outputs and turn on LED
(low byte)
- write ones to all GPIO outputs
(high
byte)
i2cset -f -y 6 0x20 7 0x33
i2cset -f -y 6 0x20 2 0xfe
i2cset -f -y 6 0x20 3 0xff
If the initialization commands above have been executed successfully the GPIO LED should be lighted up. The
power (PWR) LED should be always on. A Pi camera connected should respond to I2C accesses. We have tested
the port detection with i2cdetect. After init the GPIO port expander should show up on address 0x20 (device
6).
In the default configuration the J20 is configured that the
GPIO port expander only supplies the CAM_GPIO signal to
the CSI-2 connectors.
With the Raspberry Pi cameras the CAM_GPIO is the reset
to the camera. It must be inactive to allow the camera to
work.
The CAM_CLK by default is connected to the CAM_CLK
signals of the 120 pin dev kit connector. So R11, R12, R15,
R16, R17, and R18 are installed. 0R resistors (0603 size) or
solder jumpers.
Please make sure that the on-board GPIO expander is
configured correctly with the i2cset commands as listed
above. The clock pins must be configured as inputs. If not
then the port expander will drive against the clock signals
of the dev kit board. This potentially could cause a
hardware damage.
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