Zoe the Zero – 7 – BOM

Zoe went to the kids’ playroom for a maiden flight.  I did no tuning, she just inherited Phoebe’s PID tuning values.  The result was one perfect flight, one flight with horizontal drift, and one flight with a crash and a clipped prop (an unexpected reaction by the ESCs to ctrl-C mid-flight, I think) – replacement props are already on their way (£5 a pair).  Clearly there’s some tuning to do.

But at the same time, she is working amazingly well for a set of untuned maiden flights, so here’s the Bill Of Materials which comes to around £270 plus the unpriced bits and bobs that all cost less than a pound each.

 

9 thoughts on “Zoe the Zero – 7 – BOM

  1. Also, would DC-DC converter – NMXS1205UC do the job for voltage regulation as it was used previously in Phoebe project? or you can recommend different better one. In addition, you’ve mentioned you separated the power source for your Raspberry by adding power bank. So why voltage regulator component is still required? or it is optional?

    Thanks,
    Michael

    • I’ve not used this NMXS* regulator, so I can’t comment meaningfully. As you’ve spotted though, I only use a regulator on Pi Zero’s. Anything larger like Phoebe, Hermione and Penelope use separate battery banks so that I can test the code without powering up the motors.

  2. Thank you for the prompt reply.
    Actually I’m less familiar with abbreviations like pHAP and PCB and I feel like I need more detailed explanation, I will appreciate if you can refer me to the appropriate documentation.

    I addition, I’m using Raspberry Pi 3 B, will the mentioned pHAP fit the requirements or you would recommend different approach?
    It also will be helpful if you can post a link for pHAP examples.

    Thanks,
    Michael

    • A pHAT is the name for a PCB that plugs directly into a Raspberry Pi Zero.

      A PCB is a printed circuit board.

      There is a better size PCB hat for a 3B simply because there’s more space.

      Go to https://github.com/PiStuffing/Quadcopter for all the code samples. The .zip files are the PCB HAT designs you pass on to a PCB generator to create them.

      However, given you don’t know these very high level details, I strongly recommend taking on a ground based robot first; building and flying a quad is expensive and dangerous. I deliberate don’t include detailed instruction to protect people from bankruptcy and death! Over the last 5 years, I’d probably spent £20k developing the project from ignorance to expert; I’ve not killed myself yet luckily!

      Oh, and the model you’ve been investigating is not remote controlled, it’s autonomous, so even more complicated.

      • Oh, thank you very much!
        Yes I’m a new in an electronics field however have some experience with programming in a robotics field, had some projects previously, dealing with communication between computer and controllers and decision making systems. I’m a fan of quadrocopters, I own one with RC, it works for me for the last 4 years. Now, after numerous upgrades including adding FPV system and extending flight range, I’m highly curious about building one by my self and make it autonomous.
        I found your post in MagPi magazine, it is very attractive, and I decided to go for it.
        I already ordered F450 kit including ESC motors and mentioned in BOM Drotec IMU. So it is pretty late for me to change my decision to build similar flying robot 🙂

        • It sounds like you’ve made a good start with the stuff you’ve got already. The one thing I found to get long term autonomous flight was a lot more sensors. For example, to just hover for a minute, I’ve got a down-facing LiDAR for vertical movement + distance, and using a RPi camera pointing at the ground for horizontal movement and distance. The IMU works on for a few seconds, but after that, double integration of (accelerater – gravity) to get velocity and distance drifts significantly, hence the extra sensors vertical / horizontal distance accurately over time.

          You’ve picked the time of year though; the IMU’s drift is a lot less in above 20 degrees, which means you can stable hover for a while; the problem really hits when the temperature drops, the accelerometer values drift a lot more, and so the integration errors grows rapidly.

          Have fun!

    • The latest version of the pHAT is a custom PCB plugged into the Raspberry Pi that does 3 things:

      1. It has a voltage regular the take power LiPo voltage and converts it to 5V to power the Raspberry Pi.

      2. It includes the InvenSense MPU-9250 IMU sensor providing 3D accelerometer, gyrometer and magnetometer sensors.

      3. It provides the connectors for the motor ESCs.

      Some of the instructions are now out of date; there’s no need for the 5V power supply listed, and the T-MOTOR SMART.X frame is not made anymore – just find your own that is big enough to contain the RPI internally.

      Hope that helps.

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