Devlog #17

17 devlogs later, and here we are.. the end!
During these last 40 minutes, I worked on polishing the README and adding new sections.
I also spent a bit of time editing a short demo video that is now on YouTube.

Building this project was an insane experience and I’m really thankful to Hack Club for giving me the chance to bring it to life by funding it. Thanks guys, and now let’s see how shipping goes!

Devlog #16

What’s new ?

• Here is the launch system! It’s a 3D printed box that features a safety key, a fire button and a status led. It has 10m cable for safety reasons and it’s meant to ignite the engine.
• I’ve spent a bit of time fixing issues with bad soldering and trying to understand how I would wire the circuit but now it works and I’m pretty proud of it.
• While the key is neither inserted nor turned on, pressing the fire button won’t do anything. Once you turn the key the red led blinks and pressing the fire button sends 12V to the engine igniter.
• Design is cool but I do agree that the cable management inside is quite bad..

What’s next ?

-Shipping!! I’m polishing the last details and hope to ship very soon

Devlog # 15

What’s new ?

Parachute ! I’ve worked an hour on the parachute design and I think it came pretty good, I’ve tested it from a very low altitude and it seems to work well so I’m pretty happy with it. It’s made out of a tyvek security suit and I’ve used nylon cables for the lines.

Devlog #14.1

What’s new ?

• Nothing really important in this devlog tbh, again lot’s of tests in the code, debugging and trying new things (that didn’t worked..)
• I’ve also replaced the imu temperature value in the live telemetry by the mcu temperature because it’s a more important value to know and monitor.
  Cool things are coming! (like the parachute design )

Devlog #14

What’s new ?

• I’ve been working mainly on software those days, I had a few issues with the program running on battery, once it was started I couldn’t connect it again with the cable. To fix that I’ve added another main script that runs when the chip is powered on and adds a timer to et me interrupt boot sequence if needed.

• Then, I’ve worked on a collector for the ground station whose role is to grab the data of the other esp32 by serial and save it to a csv file (it can then be readed by the dashboard for example)

• Due to the collector needing a new telemetry parsing structure I’ve also updated how telemetry sequences are written and printed in the ground station main file

• Also, I’ve been doing some tests with the state detection algorithm to try if it detected well the different flight states (I literally threw the electronics in the air and almost smashed them on the ground, but it’s ok at least it worked well)

See you for the next devlog!

Devlog #13

What’s new ?

• A lot of work today as I’ve finished the soldering part!! Now the flight computer is done and mounted into the 3D printed sled, it was my first time soldering like that and I think it came pretty decent (though cable management looks horrible to me). The only thing that didn’t work when I powered it was the led, I spent a long time trying to understand what was wrong to finally realize that I had fried it… I replaced it with a new one and the issue was solved! (also changed the color by the way)
• Appart from soldering I’ve also added a setting to disable buzzer or led on startup and an internal temperature watchdog to monitor the temperature and prevent the chip from overheating

What’s next ?

• As I said earlier the project is almost finished! Yet I still need to add a few more features, fix some bugs and print the last parts

Devlog #12

Wow it’s really been a while since last devlog.. so ?

What’s new ?

• Well I’ve been working on a dasboard for the rocket, it uses Streamlit to display data and gathers data from a csv file that is saved on the computer. csv file is written by a local script that uses serial to catch data from the ground station via usb-c
• I’ve also been improving CAD model a little bit, that includes fillets for the fins and modifications to the instruments rack
• Also fixed a bug where calibration offsets weren’t applied properly, optimized some code and tried a lot of things in the main script.

What’s next ?

• Last week I’ve started soldering the components to the perfboard so Lapse devlog is coming very soon, I’m planning to finish this in a few days
• Once soldering is done I will test out the software in “real” conditions and print the missing parts of the rocket

Stay tuned ! ✨

Devlog #11

What’s new?

• I initially planned on adding an SD Card module but after fighting with it for almost two hours I couldn’t get it to work, it uses SPI but I don’t know why it refused cooperate..
• Then I improved the wireless transmission system by adding sequence numbers and the rocket state to the packets. Everything was working fine until it totally stopped working. I spent another hour trying to debug only to finally plug the external antenas into both ESPs which fixed the issue..
• Finally I’ve moved the rocket state detection to a separate module so the main file remains clean and is easier to debug

What’s next?

• Now that those issues are solved I’m going to create a nice dashboard I will run on my computer to display live data charts and logs, I don’t know how I’m going to design it but hopefully it will look great

On the screenshot you can see on the left logs from the rocket and on the right the live data that is pulled from the ground station by serial connection.

Devlog #10

What’s new ?

• First of all I now have the missing funds to complete the project, that’s pretty insane and I’m really happy and proud about it
• Second, I’v been working again on the external pods as the measurements for the camera were wrong and it didn’t fitted at all. I’m going to print that part to test it out but it should now be fixed.

Devlog #9.2

What’s new ?

• Some tweaks on CAD
• README ! I’v spent quite a lot of time writing the readme file, hope it’s good! I’v added several sections with a lot of details and renders from Fusion.

Devlog #9.1

What’s new ?

• I’v added a mount for the shock cord, I will put a screw and attach the cord to it. the screw will go in those holes. Both mounts will be printed separately and then glued with expoxy
• On the bottom of the engine stage I’v also added 4 holes to attach the cord to

Devlog #9

What’s new ?

• CAD: I’v updated the top cover of the trigger system box because the new fire button I’v chose needed a bigger hole
• Wirings: I’v made two schematics, one for the flight computer on wokwi and another for the trigger station on draw.io.
  Took me a bit of time to understand how to create both diagrams since it’s the first time I use those websites but I think it came pretty good.

What’s nex ?

• First I’m gonna address some issues I’v seen on the design especially in the engine stage
• Then when it’s done I’ll double check my BOM file is correct and I will probably submit for funding

Devlog #8

What’s new ?

This time I’v designed the component’s sled/rack:

• The sled will first slide in the main tube and then be attached using 4 M3 screws as you can see on both sides (I’ll also use 4 other screws to secure the soldering board on the rack itself.) I will then add heat inserts when building.

• On the other side of the sled the lipo battery will be secured using velcro straps. And on the middle I’v added 2 “windows” for cable management.

• As you can see I’v also added 3 holes (the triangle pattern) on the main tube, they’r static port holes and will be used to ensure the pressure inside the rocket is the same as outside (for the pressure sensor to get correct data)
  EDIT: I just realized I forgot to upload the screenshot showing that and now I can’t…

What’s next ?

I think I might now submit the project for funding as I am missing some critical pieces to build the rocket. I’ll also probably tweak some things in the design and log a few hours more. After than I will continue to code the flight computer.

Stay tuned! 🚀

Devlog #7

What’s new ?

I worked a lot on CAD for the past 10h of work, lot’s of headaches because of the pods (and because I forgot to hit record on lapse) but here’s what I made :

• It took me a lot of time to work on the pods because I couldn’t find a good aerodynamic design. So I designed it, re-designed it and re-re-redisigned it. Finally I have something working though it’s not perfect, I should tweak some things to make it even better.
• I also worked on designing the ground trigger system, basically it’s a box that will host the batteries to ignite the rocket, a security lock with a key and the fire button. It wasn’t very hard but it also took me a bit of time to find the correct diameters for the components.

What’s next ?

Well I think I will polish the designs perhaps add new things and fix some others, once thats done I will submit for funding to get the rest of the components I need.

Stay tuned!

Devlog #6

What’s new ?

• The rocket has now a state tracking system, what this does is that it takes the altitude, calculates the velocity and then deduces the rocket’s state (iddle, in flight, descending etc etc..)
  It took me some time to understand how velocity could be used and calculated and I also had to implement smpoothing systems to prevent the noise from the sensors to give me weird values

• I’v also added a “demo mode”, it simulates fake telemetry (altitude) so I can test the status tracking system

What’s next ?

• Well I don’t really know, I’v been strugling with live logs and I don’t really know how I could implement that, I’ll see what’s missing and what I can do to improve the rocket

Below is a screenshot of the terminal’s output, because I’m not going to take another picture of the harware as nothing really changed.. I’ll try to do better next devlog!

Devlog #5

CAD!!

Well so today I opened Fusion360 and entirely remodeled all the parts of the rocket. I had mesh files from OpenRocket but I needed to turn them into solid shapes.
I will probably have to spend more time on Fusion because I’m not sure the shoulder for the main stage is well designed and will fit properly.
Also, I might need to design something to keep the engine inside the tube so it doesn’t move.

Devlog #4

What’s new

• On each run the rocket is now assigned a random flight number for better identification (also added in transmitted packets, you’l see later why)
• Zombie connections are now killed before starting everything to prevent issues with unclosed sockets
• Clock chip frequency has been reduced (the esp is heating a lot I need to find why and fix the performances..)
• I’v added new telemetry packet flags to distinguish between telemetry and messages (I’ll probably forward live logs from the rocket to the ground station using that)

What’s coming

• Well, pretty much everything I said before (performances, live logs, telemetry saving in csv files, charts..)
• Also going to try to start the CAD in Fusion360

Devlog #3

What’s new

• I was looking at the telemetry data and noticed relative pressure mesurement was uncorrect so I fixed it (took me a moment to understand why..) - Also fixed gyro x value calculation that was wrong
• Now the main chip broadcasts it’s telemetry so it can be read by the other chip on the ground
• I’v added new buttons to the dashboard to stop Wifi and start ESPNow transmission
• Anddd last but not least, the rocket has now an internal clock which is for now used as timestamp when packets are sent

What’s on the picture

1. The “ground station” (white cable) which is an ESP32 C3
2. My breadboard with all the components which will be in the rocket (just noticed buzzer cable was disconnected)

Devlog #2

What’s new

• I’v started working on live wireless transmission so I could have live data transmission from the rocket to a ground station (another ESP32). I can now broadcast data from the rocket and it’s read by the ground station.
• I’v added new options on the dashboard, I can now remotely start the calibration process – it will be useful on ground before the launch

And now ?

Now I am going to improve the dashboard by addind new options and probably telemetry
Probably going to cleanup some code and put things in other files for better readability

1st devlog!

• Made basic CAD in OpenRocket software to design the rocket’s body and fins. It helped me understanding how aerodynamics will affect the rocket during the flight
• Started the software part, I use Python paired with a XIAO ESP32 S3 as main flight computer. I also have a BMP280 and an MPU6050 as main flight instruments. I’v added getter functions for telemetry and setters for calibration. Also added the main file with a startup function and wifi manager for wireless ground control.