Thoughtophone

See previous post . Programming via DFU worked fine, and USB serial also worked, after I added stm32f411 to the list of supported devices in stm32f4xx_hal . I should just check that serial echo example works and submit a pull request: so far I've only tried printing messages. This means I can definitely use my STM32F411 board without soldering any headers onto it, which keeps it small and lite. I've updated my project to use that board for the receiver, and a STM32F103 black pill for the transmitter. I now have a dilemma re NRF24L01+ boards. There are a few variables: With, or without RFX2401 range extender. The main issue is they draw 90mA during TX. The on board 3.3V regulator on the micro-controller board can't handle that and neither can the 5V output of the flight controller, so I would have to add a dedicated regulator, powered directly from the battery. It also draws 8mA in receive mode. Standard header vs 1.27mm edge connectors: the boards with the latt...

I figured my daughter might like to learn to fly a quadcopter during lock-down. Ages ago, I printed this frame , and bought an F3 2.0, a set of brushed motors, and some batteries. It's all just been sitting in a drawer. I need a receiver, though. It seems a lot of people do this using an NRF24L01+ and an Arduino. In fact the two have even been combined in a single board  by someone enterprising. I decided against the Arduino, because the cheap ones need 5V, and the quadcopter is powered by a single lithium battery. Also, the Arduino has limited PWM resolution. So at this point I was considering a black pill I had lying around, but it weights 6g, vs 2g for an Arduino pro micro. Then I thought about an stm32f411 black pill, which weights 2g like the pro micro. It turns out the flight controller includes a boost converter to power 5V 'peripherals' so that eliminates that argument. It's also controlled by a serial port rather than PWM, so I don't have to worry...