2024-10-29(6): Project: Git, C++, Status

Project Status 

(DONE) Motor Control: BTN9960LV 

PWM test prog configures PWM pin, but leaves it in non-functional state after exit.
- Fork there? Added test prog there? CMakery?
- Perform manually the steps that the program makes
- Look at program
- Fix program
- See how program should make use of toolcase/base/sysfs-file.h
- ⟶ CMakery

(DONE) RC Servo Control 

Check WiringPi: fork there? WiringPi test prog there?

Clarify WiringPi is not an option:
- WiringPi test prog
- If not: my Pi: ~/myapp.c
- Explain /dev/mem (man -s 4 mem)
In the long term, we will have to use PCA9685A anyway: we need 3 PWM pins in total, and the Pi has (at most?) 2. Best to give up.
- In case somebody want to try Pi nonetheless: https://github.com/dotnet/iot/blob/main/Documentation/raspi-pwm.md
  
  There appear to be clock issues ahead, as https://github.com/raspberrypi/linux/issues/1533 indicates. Beware.

(CLOSED) Proximity Sensor: VL53L1X 

Hmm. C++ needed. Wait a few hours, we’ll get to that.
⟶ what would a class VL53L1X look like?

(ACTIVE) Gyroscope (BNO055)

Fork there? Test prog there? CMakery?
Commandline program where we can try around
⟶ what would a class BNO055 look like?

Configuration Management (Err, Git)

Working with Git In Our FH-ECE21 Project

C++: OO Basics 

From Data Encapsulation …

From Functions and Methods …

Methods
this

Live hack that into the ubiquitous class point (see livecoding/point.cpp)

Homework Until 2024-11-05 

Intro 

Sensors

Two relatively autonomous tasks, (CLOSED) Proximity Sensor: VL53L1X and (ACTIVE) Gyroscope (BNO055). Good luck 🥷

Motor Controls

We have two PWM users, so we want to coordinate. Write a tool for it,

(DONE) PMW Abstraction On Top Of /sys/class/pwm/

class SysFSPWMPin can then be used from

So please lets …

Sync your fork with upstream
Read through specific “workpackage” descriptions below

(Talk about it here: 2024-11-05(6): Project, Sysprog Recap)

“Sync Your Fork” (Github term)

Please update your fork with the upstream changes from https://github.com/jfasch/FH-STECE2022.

See Working with Git In Our FH-ECE21 Project about that workflow, especially Multiple Pull Requests: Pulling Upstream Changes (“Syncing” A Fork).

What is new there:

A failing unit test or two for (DONE) PMW Abstraction On Top Of /sys/class/pwm/
Fixes for proximity-vl53l1x, see proximity-vl53l1x/proximity-vl53l1x/bin/CMakeLists.txt
Fixes, and more tests for class SysFSFile (toolcase/base/sysfs-file.h) where we can use common code from.

[jfasch@jflaptop ~/My-Builds/FH-STECE2022-x86_64]
$ ./tests/fh-stece22-suite
...
[ RUN      ] sysfs_pwm_pin_suite.get_period
/home/jfasch/My-Projects/FH-STECE2022/tests/sysfs-pwm-pin-tests.cpp:41: Failure
Expected equality of these values:
  pin.period()
    Which is: -666
  PERIOD_NS_INIT
    Which is: 10000000

[  FAILED  ] sysfs_pwm_pin_suite.get_period (0 ms)
[ RUN      ] sysfs_pwm_pin_suite.add_your_own_tests_here
/home/jfasch/My-Projects/FH-STECE2022/tests/sysfs-pwm-pin-tests.cpp:53: Failure
Failed
...

Think About Servo Interface (Group (DONE) RC Servo Control)

(SysFSPWMPin is done already, so lets focus on the servo)
How would a servo class look like? See “Software Interface” in (DONE) RC Servo Control for an idea.

Write a test for it, much like tests/sysfs-pwm-pin-tests.cpp
- The fixture for the servo tests looks the same as that of the pwm pin tests (struct sysfs_pwm_pin_suite); simply copy it. We can pull out common code later.
- A first test could look something like,
```
SysFSPWMPin pwm7(dirname);
DerEineRCServoUeberPWM rc(pwm7);

rc.set(0.0); // middle position
ASSERT_EQ(pin.duty_cycle(), 500000); // or whatever you would expect

rc.set(-45.7);
ASSERT_EQ(pin.duty_cycle(), 1500); // or whatever you would expect
```
  It is not straightforward to implement a mapping from a range of floating point values to one single duty_cycle value. It is easier though if you know what you want and start from there, so lets write the test first.

Halfbridge Horror (Group (DONE) Motor Control: BTN9960LV)

Tinker With Hardware, Think About Future.

Figure out how to operate the halfbridges
- Can we use a comparator to operate both in parallel, using one PWM?
- Do we need two?
- Ask for permission to publish a copy of the schematic and print under GPLv3 in our repo.
Think about how this can be done in software

VL53L1X (Group (CLOSED) Proximity Sensor: VL53L1X)

Make it work, simply

BNO055 (Group (ACTIVE) Gyroscope (BNO055))

Figure out what we need, by trying around with the commandline program that you brought
How could a class BNO055 look like?