Enabling file access to user home directory to be able to remotely edit python scripts with e.g. Spyder
First install samba with
sudo apt install samba samba-common-bin
Edit Samba’s config files to make the home directory of the respective user writable remotely.
sudo nano /etc/samba/smb.conf
The following lines in the file smb.conf need to be adapted as shown below
[homes]
comment = Home Directories
browseable = yes
writeable = yes
only guest = no
read only = no
furthermore the sections [printers] and [print$] should be commented out with an semicolon ;. Then test the configuration file with
testparm /etc/samba/smb.conf
We need to set a password for the standard user of the pi to enable access to its home directory
sudo smbpasswd -a <standard user>
Finally restart samba with
sudo systemctl restart smbd.service
sudo systemctl restart nmbd.service
The home shares should be addressable through the usual \<server><username> URI format.
The following commands have been taken from this page
sudo raspi-config
Activate I2C under „Interfacing Options“ > „I2C“.
In the file /boot/config.txt there should be now a line:
dtparam=i2c_arm=on
add here an additional parameter to enable 400kB/sec high speed I2C:
dtparam=i2c_arm=on,i2c_arm_baudrate=400000
Then restart the RasPi
sudo shutdown -r now
Check if I2C is really running on 400kB/sec by executing the following script (e.g. name it i2cspeed.sh and make it executable
#!/bin/bash
var="$(xxd /sys/class/i2c-adapter/i2c-1/of_node/clock-frequency | awk -F': ' '{print $2}')"
var=${var//[[:blank:].\}]/}
printf "%d\n" 0x$varthe result should be 400000.
Check I2C access to the port expander and the power meter:
sudo i2cdetect -y 1
It should show an I2C adress at 0x20 if A0 to A2 of the MCP23017 has been grounded. Furthermore address 0x40 of the INA260 should be shown.
We have to set the reset line of the MCP23017 (connected to BCM4) to output and then high to enable the chip
gpio -g mode 4 out
gpio -g write 4 1
Check the pin state with
gpio readall
Now set all Pins of GPA and GPB of MCP23017 to output
sudo i2cset -y 1 0x20 0x00 0x00
sudo i2cset -y 1 0x20 0x01 0x00
Then we can switch the first relais connected to port GPA with:
sudo i2cset -y 1 0x20 0x14 0x01
and e.g. the last (8th) with
sudo i2cset -y 1 0x20 0x14 0x80
The same commands for the relais connected to port GPB are:
sudo i2cset -y 1 0x20 0x15 0x01
sudo i2cset -y 1 0x20 0x15 0x80
With the two commands
sudo i2cset -y 1 0x20 0x14 0x00
sudo i2cset -y 1 0x20 0x15 0x00
the two relais cards are set back to zero.
Since the I2C address is 0x40 (see above) without changes on the jumpers A0 and A1 on the INA260 board we'll use this address for accessing the INA260 power meter registers.
The register definition can be found in Table 4 of Section 8.6 of the INA260 Datasheet.
| Pointer Adress Hex | Register Name | Function | Power-On Reset Value | Type |
|---|---|---|---|---|
| 00h | Configuration Register | All-Register reset, shut voltage and bus voltage ADC conversion times and averaging, operating mode. |
6127 | R/W |
| 01h | Current Register | Contains the value of the current flowing through the shunt resistor. |
0000 | R |
| 02h | Bus Voltage Register | Bus voltage measurement data. | 0000 | R |
| 03h | Power Register | Contains the value of the calculated power being delivered to the load. |
0000 | R |
| 06h | Mask/Enable Register | Alert configuration and Conversion ready flag. |
0000 | R/W |
| 07h | Alert Limit Register | Contains the limit value to compare to the selected Alert function. |
0000 | R/W |
| FEh | Manufacturer ID Register | Contains unique manufacturer identification number. | 5449 | R |
| FFh | Die ID Register | Contains unique die identification number. | 2270 | R |
We now test read/wire from/to the INA260.
We use the i2cget command on the RasPi to read the registers. The command
i2cget -y 1 0x40 0x00 w
should result in the power on reset value of 0x6127 but given as big endian (0x2761). If we want to reset the device we have to set the reset bit (15) in register 00h with the command
i2cset -y 1 0x40 0x27E1
The bit self-clears and thus we have 0x6127 again in this register after the reset.
The command
i2cget -y 1 0x40 0x01 w
should yield a value between 0xffff and 0x0001 (again in big endian given as 0xffff and 0x0100) if no current flowing (noise of readout is causing fluctuation by one bit. The command
i2cget -y 1 0x40 0x02 w
should yield a similiar output for the bus voltage. The power can be read by
i2cget -y 1 0x40 0x03 w
and is usually 0x0000. The manufacturer ID Register and the Die ID register can be read out by the commands
i2cget -y 1 0x40 0xFE w
i2cget -y 1 0x40 0xFF w
and yield 0x5449 and 0x2270 respectively.
sudo raspi-config
Activate SPI under „Interfacing Options“ > „SPI“. Then restart the RasPi
sudo shutdown -r now
Check if SPI driver has been enabled via:
modprobe spi_bcm2835
should not return any error messages.
This follows the explanation in KY-040 Rotary Encoder with Linux on the Raspberry Pi
First enter following line into /boot/config.txt
#enable rotary encoder
dtoverlay=rotary-encoder,pin_a=21,pin_b=20,relative_axis=1
dtoverlay=gpio-key,gpio=16,keycode=28,label="ENTER"
<pin_a> specifies the CLK pin, <pin_b> specifies the DT pin and <gpio> the pin for the enter button switch. Then reboot the RasPi. Warning first reboot may take a bit longer since the driver gets activated, so don't get impatient! Then install the evtest tool and check out the encoder:
sudo apt install evtest python3-evdev
The new device can be found under /dev/input/event0 and /dev/input/event1 button and axis respectively, and can be tested with
evtest /dev/input/event0
evtest /dev/input/event1
Treelib (for menu in GUI):
pip3 install treelib
evdev (driver for Rotary encoder see above section)
PIL (for OLED Display):
sudo apt install python3-pil python3-pil.imagetk
pytest (for code testing):
pip3 install pytest
The wiki uses Markdown syntax.