When few months ago my older daughter (10 years old) started to express interest in FPV quadcopters, I was both happy and concerned. Happy, since I would have someone to fly with. Concerned, since she has no idea how to fly, I do not have a quadcopter for her and there is a big chance she will get bored fast. So, instead of getting her a brand new, cheap, standard off-the-shelf drone, I checked my repository of “spare” parts and drones, purchased this and that and week later “Omlette du fromage” came to life…
Thanks to Airbot I got my hands on a new STM32 F7 flight controller: Omnibus F7.
Before we proceed, small note.
I am a huge fan of F7 flight controllers. In a year, they will be a main line of high performance FC on the market. STM32F7 with built-in UART inverters solves so many issues STM32 F4 boards are facing. But, F7 are not there yet. Currently available boards uses STM32F745 CPU in 100 pin packages. They are just too big to comfortably fit 36x36mm format. You place CPU and most of the PCB is taken. Than means there is no space left for either connectors or OSD for example. What we are waiting are FC with STM32F722 in 64pin package!
Airbot Optimus F4 series is one of my favorite flight controllers. Two of my quads are flying thanks to them. They might not be the best or the famous ones, but they get the job done. And that is what counts.
Unfortunately, they are not free of faults (and what is?) and each next revision is trying to fix some problems. Sometimes by introducing new one. Right now, there are 4 hardware revisions, not always fully compatible between each other.
Here is a summary of all 4 revisions…
Looks like BLHeli team is not wasting their time and is preparing something new for our multirotors. After BLHeli_S, we will also have BLHeli_32.
According to an announcement posted on RCGroups, new software for ESCs (and new ESC of course, since it will not be compatible with current Atmel and SiLabs MCU) will be:
- Running 32-bit MCU, Cortex-M0 at 48MHz (STM32F0 ??). Which, in my opinion, is a very logical step to take. Please remember, that all SiLabs (Silicon Labs) MCU powering most of our ESC, are under the hood old Intels 8051. And please remember that Intel 8051 was created in 1980. 37 years ago…
- There are few places where additional computational performance can be spent. For example:
- Programmable PWM frequency up to 48kHz
- Auto timing for better efficiency
- Programmable brake on stop power, very useful for folding propellers
- Voltage and current limiting
- and more…
ESCs with BLHeli_32 are not available yet, but Airbot already announced Wraith32 Plus (with voltage and current limiting) and Wraith32 Mini (without voltage and current limiting).