ECE 320 · Week 10
Modern Computer: Embedded Systems
The demo order: two buses, a service, and one question about your own capture or overlay.
Week 10 of 10 · Das Frite
ECE 320 · Week 10 · In class
The demo order: two buses, a service, and one question about your own capture or overlay.
- The project uses two of I2C, SPI, and UART, and it starts as a service.
- The README names those two buses.
- Restart the service on the second pass and show the same two buses again.
ECE 320 · Week 10 · In class
The homework is the question you will ask your partner about their overlay, and the answer you expect.
- Write it before the demo.
ECE 320 · Week 10 · Lecture
A service starts without you
[Unit]
Description=Project data logger
[Service]
ExecStart=/usr/local/bin/project-logger
Restart=on-failure
[Install]
WantedBy=multi-user.targetSave it as /etc/systemd/system/project-logger.service; ExecStart needs an absolute path.
ECE 320 · Week 10 · Lecture
Driving it with systemctl
| Command | Does |
|---|---|
sudo systemctl daemon-reload | rereads unit files after an edit |
sudo systemctl enable --now project-logger | starts it now and at every boot |
systemctl status project-logger | running or not, and its last log lines |
sudo systemctl restart project-logger | the demo's second pass |
journalctl -u project-logger -b | everything it printed this boot |
ECE 320 · Week 10 · Lecture
The demo, in order
- Show the service running after boot, with no login needed to start it.
- Show the first bus doing its job, then the second.
- Answer one question about your own capture or overlay.
- Restart the service and show the same two buses again.
ECE 320 · Week 10 · Lecture
A README someone else can follow
- What the system does, in two sentences.
- The two buses it uses, and the part on each.
- How to build it, install the service, and enable any overlay it needs.
- How to tell it is working: the log line or output to look for.
ECE 320 · Week 10 · Lab
Lab
- Demonstrate the project.
- It uses two of this course's buses and starts as a service. Answer one question about your own capture or overlay. Second pass: restart the service and show the same two buses again.
- Assemble the lab hand-in: The live demo of a project that uses two of the course's buses and starts as a service, and the repository README that names those two buses.
ECE 320 · Week 10 · Lab
Hand in
The live demo of a project that uses two of the course's buses and starts as a service, and the repository README that names those two buses.
ECE 320 · Week 10 · Homework
Homework
- Write the one question you will ask your partner about their overlay, and the answer you expect.
ECE 320 · Week 10 · Homework
Turn in
The question and the expected answer.
ECE 320 · Week 10 · Read
Read
On the lab site: Module 12, A whole system, has no demo hand-in. This week grades the demo and the README that names the two buses.