This version (19 May 2023 15:16) was approved by Mark Thoren.The Previously approved version (18 May 2023 21:12) is available.
Table of Contents
EVAL-CN0575-RPIZ User Guide
General Description
The EVAL-CN0575-RPIZ is a 4-layer printed circuit board (PCB) that allows evaluation of the CN0575 10BASE-T1L Field Device Development Platform with Class 12/13 Single Pair Power over Ethernet (SPoE). Designed for use on the Raspberry Pi platform, the CN0575 hardware features a 40-pin GPIO header, and follows the same mechanical dimensions as a standard HAT.
To allow board stacking and development of field device applications using Raspberry Pi HATs, an additional GPIO header with extended leads is included with each evaluation board. However, the CN0575 can also be used on its own as a basic temperature sensing field device with remote user input/output via an onboard button and LED.
Evaluation Board Hardware
Primary Side
10BASE-T1L Port (P1 and P2)
The CN0575 evaluation board uses a single port 10BASE-T1L device and can be connected to a link partner using either one of the two physical connectors provided:
- The P1 terminal block is used for connecting individual wires. Connect the twisted pair to pins 1 and 2, and the shield (if available) to pin 3. Secure the connections by tightening the screws on the terminal block.
- The P2 port is used for connecting standard IEC 63171-6 cables directly from a 10BASE-T1L-capable controller unit.
PHY Status Indicators (LED0 and LED1)
LED0 and LED1 are the ADIN1110 status indicators, and can be configured to display various activities via the device registers.
By default, LED0 is set to turn on when a link is established and blink when there is activity; while LED1 is disabled. Refer to the LED Control Register in the ADIN1110 data sheet for a full list of available functions.
General Purpose LED and Button (ALERT and TEST)
The EVAL-CN0575-RPIZ evaluation board includes a simple button (TEST) and LED (ALERT) circuit that can be respectively used as a digital input and a general purpose indicator. This circuit is controlled by the Raspberry Pi by default (via GPIO16 and GPIO26), but can alternatively be used with external hardware by changing the appropriate jumper settings (refer to Connecting the General Purpose LED and Button to External Hardware).
The GPIO16 pin is normally pulled high in this circuit, but will read low when the TEST button is pressed.
SPoE PD Power Class Selection (JP1 and JP2)
By default, the LTC9111 SPoE PD controller included in the CN0575 circuit is configured for PD Class 12. If a different PD class is required for the application, the JP1 and JP2 solder jumpers should be reconfigured to match the desired class.
| JP1 Shunt Position | JP2 Shunt Position | PD Class | VPD(min) | PPD(max) |
|---|---|---|---|---|
| Across Pins 2 and 3 | Across Pins 2 and 3 | 10 | 14 V | 1.23 W |
| Across Pins 2 and 3 | No Shunt Inserted | 11 | 3.20 W | |
| Across Pins 2 and 3 | Across Pins 1 and 2 | 12 | 8.40 W | |
| Across Pins 1 and 2 | Across Pins 2 and 3 | 13 | 35 V | 7.70 W |
| Across Pins 1 and 2 | No Shunt Inserted | 14 | 20.0 W | |
| Across Pins 1 and 2 | Across Pins 2 and 3 | 15 | 52.0 W |
The CN0575 was designed and evaluated for PD Classes 12 and 13. However, Classes 10 and 11 may still be usable, depending on the power requirements of the Raspberry Pi model used (and its peripherals).
Warning: Do not use PD Classes 14 and 15. The EVAL-CN0575-RPIZ evaluation board is not designed to handle these higher power specifications.
Secondary Side
ADIN1110 SW Power-Down Enable and SPI Configuration (JP3 to JP5)
The EVAL-CN0575-RPIZ evaluation board uses the default hardware configuration for the PHY specified in the ADIN1110 data sheet. If a different operating mode is required for the application, the ADIN1110 should first be placed into software power-down and then configured appropriately via the device registers.
Refer to the table below on setting the JP3 jumper to enable/disable the software power-down feature:
| JP3 Setting | Software Power-Down Configuration |
|---|---|
| Open | PHY enters software PD mode after a reset operation (Default). |
| Shorted | PHY does not enter software PD mode after a reset operation. |
The ADIN1110 supports both generic SPI and the OPEN Alliance SPI protocol in its communication. Refer to the table below on setting JP4 and JP5 to select the SPI protocol:
| JP4 Setting | JP5 Setting | SPI Protocol |
|---|---|---|
| Open | Open | OPEN Alliance with Protection |
| Open | Shorted | OPEN Alliance without Protection |
| Shorted | Open | Generic SPI with 8-bit CRC |
| Shorted | Shorted | Generic SPI without 8-bit CRC (Default) |
ADT75 I²C Bus Address Selection (JP6 to JP8)
The I²C bus address of the onboard ADT75 temperature sensor is dependent on the settings of the JP13, JP14, and JP15 solder jumpers. Note: The CN0575 device tree overlay in ADI Kuiper Linux has the temperature sensor I²C address set to the default 0x48.
If there is a need to reassign the ADT75 address, refer to the following table:
| Jumper Settings | I2C Bus Address | ||
|---|---|---|---|
| JP6 | JP7 | JP8 | |
| B | B | B | 0x48 (Default) |
| B | B | A | 0X49 |
| B | A | B | 0X4A |
| B | A | A | 0X4B |
| A | B | B | 0X4C |
| A | B | A | 0X4D |
| A | A | B | 0X4E |
| A | A | A | 0X4F |
Optional GPIO Pins (JP9 to JP13)
By default, some functions of the EVAL-CN0575-RPIZ are connected to various GPIO pins of the Raspberry Pi. If these features will not be used in the application, the corresponding jumpers can be removed - doing this will allow these GPIO pins to be used for other external hardware.
| Jumper | GPIO | Circuit Function | Description |
|---|---|---|---|
| JP9 | GPIO27 | ADIN1110 Reset | This an active low ADIN1110 input that resets the part when held low for >10 μs. |
| JP10 | GPIO22 | ADIN1110 Link Status Output | This is an active high ADIN1110 output that indicates whether a valid 10BASE-T1L link has been established. |
| JP11 | GPIO23 | Time Stamp Capture Signal | Assert this pin to timestamp the latest incoming frame received by the ADIN1110. The captured timestamp will be stored in the TS_EXT_CAPT0 and TS_EXT_CAPT1 registers. |
| JP12 | GPIO24 | Time Stamp Timer Signal | This pin is connected to the TS_TIMER pin of the ADIN1110. When the TS_TIMER output is enabled in the device registers, a waveform with high and low times set by the TS_TIMER_HI and TS_TIMER_LO registers is generated. |
| JP13 | GPIO6 | Overtemperature Indicator | This pin is asserted when the onboard ADT75 temperature sensor is put into one-shot mode and the temperature measurement exceeds TOS (80 °C; default value). By default, the indicator is active low and will only be de-asserted when the temperature drops below THYST (75 °C; default value). The temperature sensor can be reprogrammed to change the polarity of this pin, the de-assertion requirement, and the values of TOS and THYST. |
General Purpose LED and Button Connections (JP14 and JP15)
While normally functioning as a digital input and general purpose indicator respectively, the TEST button and ALERT LED can alternatively be used for external applications by changing the settings of the appropriate jumpers. JP14 is used to set the button connection, while JP15 is used to set the LED connection.
| JP14 Setting | Connection |
|---|---|
| Open | TEST button is connected to GPIO16 of the Raspberry Pi (Default). |
| Shorted | TEST button is not connected to the Raspberry Pi. |
| JP15 Setting | Connection |
|---|---|
| Open | ALERT LED is connected to GPIO26 of the Raspberry Pi (Default). |
| Shorted | ALERT LED is not connected to the Raspberry Pi. |
External hardware can be connected to the TEST button and ALERT LED using the BTN_IO and LED_IO test points, respectively.
System Setup
Required Equipment
Hardware
- EVAL-CN0575-RPIZ Circuit Evaluation Board
- Raspberry Pi Model 3B (or higher)
- Micro-SD Card for Raspberry Pi
- 10BASE-T1L media converter, either:
- EVAL-ADIN1100EBZ Product Evaluation Board
- Other 10BASE-T to 10BASE-T1L media converter
- USB to 10BASE-T1L
- Power Source, either:
- 10BASE-T1L Power Coupling Network Board w/ SPoE PSE or DC Power Supply
- USB-C or USB-Micro 5V wall adapter (plugged directly into Raspberry Pi)
- Host Windows, Linux, or Mac computer
Software
Documentation
- CN0575 Circuit Note
Block Diagram
Setup with SPoE via PSE or DC Power Supply:
Setup without SPoE (USB-Powered Application):
Software Setup
Downloading and Flashing the Micro-SD Card
To use the EVAL-CN0575-RPIZ with the Raspberry Pi, the micro-SD card should be preloaded with Analog Devices Kuiper Linux, a distribution based on Raspbian from the Raspberry Pi Foundation that incorporates Linux drivers for ADI products as well as tools and other software products.
Complete instructions, including where to download the SD card image, how to write it to the micro-SD card, and how to configure the system are provided at Kuiper Images.
Configuring the Micro-SD Card
The Linux kernel requires a matching device tree overlay to identify the devices on the EVAL-CN0575-RPIZ. The CN0575 overlay file is included with the Analog Devices Kuiper Linux and simply needs to be enabled.
To do this, follow the Hardware Configuration procedure under Configuring the SD Card for Raspberry Pi Projects in the Kuiper Images page. Enable the CN0575 overlay by adding the following line to config.txt:
dtoverlay=rpi-cn0575
Save the file and reboot the system by entering the following command in the console:
analog@analog:~$ sudo reboot
Determining the IP Address of the CN0575
Follow the below procedure to determine the IP address assigned by the Raspberry Pi to the EVAL-CN0575-RPIZ:
- Complete the hardware setup described in the Basic Operation section.
- Remove the Ethernet cable from the EVAL-ADIN1100EBZ evaluation board and connect it directly to the Raspberry Pi.
- Run PuTTY and connect to the Raspberry Pi via SSH. For the Host Name (or IP address), use analog.local.
- Enter the command ifconfig in the console.
- The IP address of the EVAL-CN0575-RPIZ board will be listed as inet under adin1110-0. In the example below, the IP address is 169.254.158.120.
Basic Operation
To establish a 10BASE-T1L connection to a Raspberry Pi using the EVAL-CN0575-RPIZ evaluation board and run a basic temperature measurement example, follow the below procedure:
- Ensure that the jumpers and switches of the EVAL-ADIN1100EBZ are configured to the default settings.
- Insert the micro-SD card into its slot on the Raspberry Pi.
- Connect the EVAL-CN0575-RPIZ circuit evaluation board to the Raspberry Pi GPIO header.
- Using an Ethernet cable, connect P5 on the EVAL-ADIN1100EBZ evaluation board to an RJ-45 port on the computer.
- Using a micro-USB cable, connect P401 on the EVAL-ADIN1100EBZ evaluation board to a USB port on the computer.
- Operation with SPoE PSE or DC Power Supply: (Skip to step 7 if using a USB wall adapter instead)
- Set the output of the PSE or DC power supply to either 24V (Class 12) or 55V (Class 13), depending on the settings of JP1 and JP2 on the CN0575 board.
- Using wires, connect the output of an SPoE power coupler to the P1 terminal block on the EVAL-CN0575-RPIZ circuit evaluation board. Similarly, connect the data input of the power coupler to the P101 terminal block on the EVAL-ADIN1100EBZ evaluation board.
- Connect the output of the SPoE PSE (or DC power supply) to the power input of the SPoE power coupler and enable it.
- Operation without SPoE (USB-Powered Application):
- Using wires, connect the P1 terminal block on the EVAL-CN0575-RPIZ circuit evaluation board to the P101 terminal block on the EVAL-ADIN1100EBZ evaluation board.
- Connect the USB wall adapter to the power connector on the Raspberry Pi.
- Wait for the LINK LED on the EVAL-CN0575-RPIZ circuit evaluation board and the LED_0 LED on the EVAL-ADIN1100EBZ evaluation board to turn on and start blinking at the same time. This indicates that a 10BASE-T1L link has been established.
- On the host PC, run PuTTY and connect to the Raspberry Pi using the EVAL-CN0575-RPIZ IP address.
- In the Raspberry Pi console, navigate to the examples directory of pyadi-iio. Run the temperature measurement example by entering the following command:
.../pyadi-iio/examples $ sudo python lm75_example.py
More Complete Example with Digital I/O
A more complete example that blinks the onboard LED and reads the pushbutton is also provided. Note that this script can be run either directly on the Raspberry Pi, or from a remote host computer.
From the Raspberry Pi command line, run:
.../pyadi-iio/examples $ sudo python cn0575_example.py
Or from PowerShell on a Windows remote host, run:
...\pyadi-iio\examples> python .\cn0575_example.py
The script will attempt to automatically locate the CN0575 over the network connection. The CN0575's IIO context URI can also be passed to the script explicitly, where www.xxx.yyy.zzz is the board's IP address:
C:\temp\pyadi-iio\examples> python .\cn0575_example.py ip:www.xxx.yyy.zzz
Typical output is shown below:
Schematic, PCB Layout, Bill of Materials
Additional Information and Useful Links
Hardware Registration
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End of Document
resources/eval/user-guides/circuits-from-the-lab/cn0575.txt · Last modified: 18 May 2023 23:35 by Mark Thoren