Firmware for ATmega328P that monitors a push button to turn on/off a switching power supply. Supplies a shutdown signal to another MCU so that it can shutdown cleanly before the power supply is switched off.
Also implements ADC measurements in response to SPI requests.
Intended for use with Raspberry PI boat computer project. The
corresponding hardware design is at:
The script shutdown_monitor.py is used to control and monitor
the GPIO pins on the Raspberry Pi to work in concert with this
firmware. This script is copied to /usr/bin. A systemd service file is
shutdown_monitor.service and is copied to /lib/systemd/service.
Enabling and starting the service using systemd
systemctl enable shutdown_monitor.service
systemctl start shutdown_monitor.service
To disable the service from starting at boot
systemctl disable shutdown_monitor.service
Diagram made using gaphor
Install Rust nightly.
rustup toolchain install nightly-2021-01-07
Then run:
cargo +nightly-2021-01-07 build --release
The final ELF executable file will then be available at target/avr-atmega328p/release/power-monitor-rust.elf.
The fuses are changed from the default and need to be updated
avrdude -p atmega328p -c <your programmer here> -U lfuse:w:0xc2:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m
The compiled firmware (power-monitor-rust.hex) can be programmed into the hardware using
avrdude -p atmega328p -c <your programmer here> -U flash:w:power-monitor-rust.hex
To create the hex file, use avr-objcopy
avr-objcopy -O ihex target/avr-atmega328p/release/power-monitor-rust.elf power-monitor-rust.hex
This can also be done with the makefile target 'program', or make program
-
Rev B
-
LED1 attached to PB0
-
LED removed from SHUTDOWN
-
SHUTDOWN added pulldown
-
MCU_RUNNING moved from PD3 to PB1
-
MCU_RUNNING added pulldown
-
LC circuit added to AVCC
-
Optional 12V ADC measurement to ADC7
-
Rev A (original)
[proto-board]
ATmega328P-28P3
+--------------------+
| |
RESET-|1 PC6 PC5 29|-ADC5
RX-|2 PD0 PC4 27|-ADC4
TX-|3 PD1 PC3 26|-ADC3
BUTTON-|4 PD2 PC2 25|-ADC2
LED5-|5 PD3 PC1 24|-ADC1
ENABLE-|6 PD4 PC0 23|-ADC0
VCC-|7 22|-GND
GND-|8 21|-AREF
SHUTDOWN-|9 PB6 20|-AVCC
EEPROM-|10 PB7 PB5 19|-SCK
LED4-|11 PD5 PB4 18|-MISO
LED3-|12 PD6 PB3 17|-MOSI
LED2-|13 PD7 PB2 16|-CS
LED1-|14 PB0 PB1 15|-MCU_RUNNING
| |
+--------------------+
ATmega328P-32A
+--------------------------+
| |
3.3-|4 VCC PB0 12|-LED1
3.3-|18 AVCC PB1 13|-MCU_RUNNING
CAP->GND-|20 AREF PB2 14|-CS
GND-|3 GND PB3 15|-MOSI
| PB4 16|-MISO
A6-|19 ADC6 PB5 17|-SCK
A7-|22 ADC7 PB6 7|-SHUTDOWN
| PB7 8|-EEPROM
-|30 PD0 |
-|31 PD1 PC0 23|-A0
BUTTON-|32 PD2 PC1 24|-A1
-|1 PD3 PC2 25|-A2
EN-|2 PD4 PC3 26|-A3
-|9 PD5 PC4 27|-A4
-|10 PD6 PC5 28|-A5
-|11 PD7 PC6 29|-RESET
| |
+--------------------------+
power-monitor-rust is licensed under the GNU General Public License v3.0 or later. See LICENSE for more info.