nppilot

Looks like the plane is too heavy. It took off OK on the first try, but I couldn’t get it to lift on five goes past that. The first flight was probably due to the little bit of extra voltage a freshly charged battery has.

I picked up yet another board to try in my never-complete car autopilot project. This time it’s a Pixhawk PX4 (from ETH here in Zurich, woo!) with a FrSky PPM receiver, u-blox GPS, and 433 MHz telemetry mounted on my trusty P-28 Trojan.

I have this long term, never complete project to make a self driving RC car. I’m making progress on the third reboot and finished up the rover board today: On the board is a NAZE32 running Cleanflight for the sensors and real time control, a GPS, a Frsky receiver, a Beaglebone Black for logging, and a Adafruit LCD for status.

I’ve ported the Adafruit 1.8″ LCD driver to the new-ish Arduino ESP8266 port and done an optimisation pass. Short story is that the demo that comes with the board is down from 6083 ms to 3424 ms, and big operations like fill screen is down from 1454 ms to 157 ms.

I’m hacking on porting NuttX to the Teensy LC instead of using PJRC’s excellent Arduino support. For reference, here’s the Arduino pin mapping to the native pin: 0 PTB16 1 PTB17 2 PTD0 3 PTA1 4 PTA2 5 PTD7 6 PTD4 7 PTD2 8 PTD3 9 PTC3 10 PTC4 11 PTC6 12 PTC7 13 PTC5 14 PTD1 15 PTC0 16 PTB0 17 PTB1 18 PTB3 19 PTB2 20 PTD5 21 PTD6 22 PTC1 23 PTC2 24 PTE20 25 PTE21 26 PTE30 This was made by running core_pins.

A while ago I posted about cutting the ACME Arietta boot time down from ~30 s to ~4 s. Here’s the hacks I did to get there. After the kernel has finished initialising it runs ‘init’ which is responsible for setting up the system and starting any services.

I’m using golang as the language for my self balancing robot project. It should be interesting as golang is designed for server loads, not for realtime, but the bot will need to update at 100 Hz (10 ms/cycle) to say upright.

I’m working on a self balancing robot as a coming-into-winter-something-inside-sounds-good project. Today I got it driving about: not balancing, not smart, but still a good milestone. It’s been a lot of fun due to the different tech involved.

After a night of hacking I have the cutest console ever: fbcon on my Arietta G25 showing on a 84×48 Nokia 3310 LCD thanks to fbtft. The nice thing is it’s tiny enough to fit on my RC car but shows as a standard framebuffer so will work with everything.

Short story: my Arietta G25 now boots to prompt in 3.9 s instead of the stock 50.7 s. Nice. I had a hack about with reducing the boot time of the Arietta G25 ARM9 based Linux board.