Improvements to the CanSat kit
Posted: Thu 26 Sep 2024 16:21
Hello,
I am one of the people who provided technical support for Belgium's 2023-2024 CanSat edition and would like to take this opportunity to provide feedback on how the CanSat kit could be improved.
The main improvement I would like is to add robustness for when the Can not be retrieved. Last year's addition was an eye-opener, since due to extremely bad weather, only 6 out of the 32 cans where retrieved. The cans that weren't retrieved often had limited telemetry because the teams had to do blind pointing with their antenna due to the cans disappearing above the clouds seconds after the launch.
My main takeaways on retrievability of the cans:
- teams that deviated from the standard 433 MHz radio module (and go for e.g. 2.4 GHz module instead) had significantly better telemetry
- teams that included a GPS sensor had more chance of having their can retrieved
I would therefore want to propose the following:
1. Replace the RFM69HCW with the RFM95 LoRa Module. This radio module operates over very large distances (> 2 km), is low power, and operates at 868 MHz, so multiple cans inside the rocket interfere less with each other than multiple 2.4 GHz cans (the higher the modulation frequency, the more frequency separation you need to avoid interference).
2. Include a GPS or other GNSS module. I would preferably want a GNSS module that supports Galileo, since it's the European GNSS system, and it's more accurate than GPS.
Something else that would be useful is the addition of an SD-card module to the kit. That way, if a team has bad telemetry, but their can is retrieved, they still have all their data. There were already a lot of teams that bought an SD-card module last year, so why not include it by default.
Lastly, I'm not a huge fan of the RPi Pico. It is not very powerful (though good enough for most teams) nor reliable (the bootloader can sometimes act up). I think an ESP32-based system would be better. There are many cheap options available. If you do want to spend a bit more money, you could go for Adafruit's ESP32 Feather V2 module, which has integrated 2.4 GHz Wifi antenna + Bluetooth, integrated LiPo connection and charger (so no need for the LiPo boost charger module anymore), and has a large Adafruit ecosystem (“Wings”) for additional functionality. The switch to a new microcontroller is certainly not as critical as the previously mentioned improvements, but I think it will be beneficial in the long run.
Let me know what you think, I would be happy to discuss it!
I am one of the people who provided technical support for Belgium's 2023-2024 CanSat edition and would like to take this opportunity to provide feedback on how the CanSat kit could be improved.
The main improvement I would like is to add robustness for when the Can not be retrieved. Last year's addition was an eye-opener, since due to extremely bad weather, only 6 out of the 32 cans where retrieved. The cans that weren't retrieved often had limited telemetry because the teams had to do blind pointing with their antenna due to the cans disappearing above the clouds seconds after the launch.
My main takeaways on retrievability of the cans:
- teams that deviated from the standard 433 MHz radio module (and go for e.g. 2.4 GHz module instead) had significantly better telemetry
- teams that included a GPS sensor had more chance of having their can retrieved
I would therefore want to propose the following:
1. Replace the RFM69HCW with the RFM95 LoRa Module. This radio module operates over very large distances (> 2 km), is low power, and operates at 868 MHz, so multiple cans inside the rocket interfere less with each other than multiple 2.4 GHz cans (the higher the modulation frequency, the more frequency separation you need to avoid interference).
2. Include a GPS or other GNSS module. I would preferably want a GNSS module that supports Galileo, since it's the European GNSS system, and it's more accurate than GPS.
Something else that would be useful is the addition of an SD-card module to the kit. That way, if a team has bad telemetry, but their can is retrieved, they still have all their data. There were already a lot of teams that bought an SD-card module last year, so why not include it by default.
Lastly, I'm not a huge fan of the RPi Pico. It is not very powerful (though good enough for most teams) nor reliable (the bootloader can sometimes act up). I think an ESP32-based system would be better. There are many cheap options available. If you do want to spend a bit more money, you could go for Adafruit's ESP32 Feather V2 module, which has integrated 2.4 GHz Wifi antenna + Bluetooth, integrated LiPo connection and charger (so no need for the LiPo boost charger module anymore), and has a large Adafruit ecosystem (“Wings”) for additional functionality. The switch to a new microcontroller is certainly not as critical as the previously mentioned improvements, but I think it will be beneficial in the long run.
Let me know what you think, I would be happy to discuss it!