Tutorials
Note: If you have multiple gateways, all commands can also take a --gateway option to specify which one. For brevity, that option is omitted from the below examples.
How to communicate with peripherals on the I2C bus with lager CLI
Intro
In order to debug hardware designs with chips that utilize an I2C bus, it's often handy to have a way of communicating with the bus directly. The Lager Gateway has a built-in I2C peripheral that you can use to communicate with your I2C chips or microcontrollers.
Setup
Install the latest version of the lager-cli tool, and confirm that you are able to communicate with your Lager Gateway.
Sending Bytes
lager-cli includes a i2c write command for transmitting bytes via I2C. This command has a mandatory device argument, which is the I2C address of the device you're writing to (in either 0x hex or integer notation), as well as one or more bytes of data to transmit. An optional --reg argument can be provided with the address of the register to send the bytes to. The datatype of the provided bytes can be set with the --type argument.
# Write 0xFFFF to device 0x12 (18)
> lager i2c write --type hex 0x12 0xFF 0xFF
# Write 0x12 0x34 to device 0x12 (18) register 0x10 (16)
> lager i2c write --type hex --reg 0x10 0x12 0x34
# Write "hello" to device 0x12 (18)
> lager i2c write --type string 18 test
Requesting Bytes
lager-cli also includes a i2c read command for requesting bytes from a specific I2C address. A --length argument can be used to set the number of bytes to request, otherwise one byte will be requested.
# Read 1 byte from device 0x12 (18)
> lager i2c read 0x12
# Read 2 bytes from device 0x12 (18) register 0x10 (16) in hex format
> lager i2c read --length 2 --type hex --reg 16 0x12
# Read a 5-byte string from device 0x12 (18)
> lager i2c read --length 5 --type string 0x12
How to communicate with peripherals on the SPI bus with lager CLI
Intro
In order to debug hardware designs with chips that utilize an SPI bus, it's often handy to have a way of communicating with the bus directly. The Lager Gateway has a built-in SPI peripheral that you can use to communicate with your SPI chips or microcontrollers.
Setup
Install the latest version of the lager-cli tool, and confirm that you are able to communicate with your Lager Gateway.
SPI Modes
To change the SPI mode (see https://en.wikipedia.org/wiki/Serial_Peripheral_Interface), use the --mode argument.
Chip Selects
Currently only one hardware chip select pin works. TODO fix this.
Reading Bytes
lager-cli includes an spi read command for reading bytes from an SPI peripheral. It accepts a mandatory length argument which determines how many bytes to read.
# Read 4 bytes using mode 0 (the default)
> lager spi read 4
# Read a 5-byte string from SPI using mode 1
> lager spi read --mode 1 --type string 5
# Read 3 integer bytes from SPI at 500 KHz
> lager spi read --speed 500000 --type int
Writing Bytes
lager-cli includes an spi write command for writing bytes to an SPI peripheral. It accepts an arbitrary number of bytes to send.
# Write 4 bytes using mode 0 (the default)
> lager spi write 0x12 0x34 0x56 0x78
# Write the string "hello" using mode 3 at 500 Khz
> lager spi write --mode 3 --speed 500000 hello
# Write 3 integers
> lager spi write 0 127 255
Transferring Bytes
lager-cli includes an spi transfer command that accepts an arbitrary number of bytes to send to an SPI peripheral, and returns the bytes that were simultaneously received.
# Write the string "hello" and return the received bytes
> lager spi transfer --type string hello
Lager SPI Received 5 bytes: world
Stream serial output from a DUT
1. List your serial ports: lager gateway serial-ports.
➜ ~ lager gateway serial-ports
/dev/ttyS0 - Lager Gateway serial port
/dev/ttyACM0 - SEGGER VL805 USB 3.0 Host Controller; serial number 123456789
/dev/ttyUSB1 - Future Technology Devices International, Ltd FT2232C/D/H Dual UART/FIFO IC; serial number FT1ABCDE
2. Use the serial port device name with lager uart to stream output from that serial port and save it to a file: lager uart --serial-port /dev/ttyACM0 | tee serial.log. This will stream the output to your console and save it to a file called serial.log. See the UART command reference for the full set of options available to lager uart.
➜ ~ lager uart --serial-port /dev/ttyACM0 | tee serial.log
test_mpu9250_drv.c:44:test_who_am_i_read:FAIL: Expected 113 Was 0
test_mpu9250_drv.c:62:test_sample_rate_divider:FAIL: Expected 1 Was 0
test_mpu9250_drv.c:79:test_enabling_disabling_fifo_modes:FAIL: Expected 1 Was 0
test_mpu9250_drv.c:98:test_gyro_fs_select:FAIL: Expected 1 Was 0
test_mpu9250_drv.c:36:test_42:PASS
test_mpu9250_drv.c:37:test_blinky:PASS
-----------------------
6 Tests 4 Failures 0 Ignored