Its been a few Hat’s since I started the latest series using SPI as backbone, so it’s time to consolidate on those I want to finish first. I have a list of close to 40 different Hat’s I want to make. Key to them all is that I use STM32F405 as a reusable component to cover 90%+ of source code – once I have infrastructure and AL on one I basically have it on them all leaving only specialized libraries and a few lines of Hat depending soft-wiring.
- XPortHub have a lot of the handy interfaces + storage memory and SD Card. This is my current Development base as well.
- 32 x Servo/IO is mostly needed for Servo control.
- 8 x DC is small DC motors.
- 7 x 5 Wire Stepper is very handy for those low cost, small steppers.
- NB-IoT gives me a way to communicate using global Telecom on very long distance as long as I have GSM, 2G, 3G or 4G coverage.
- LoRa gives me free up to 12Km range.
- 12xPWM is very handy for various reasons including solenoids, dc motors, small 3-phase motors and Nema17 style stepper motors.
- Sensor Hat gives me an interface to various analogue & digital sensors.
- Wifi & Ethernet Hat is not a priority since it basically cover the same as Raspberry PI, but I like ESP32 to much to not include it on the list + a majority of infrastructure needed here is made.
- My 60V PSU Hat was not intended as a Hat, but it is a nice option if I use motors and have only one PSU.
- 3D sensor & GPS is the latest Hat that I have not started on yet. I have GPS on LoRa as well, but decided to add GPS on the planned 3D sensor. I will need multiple of these on the larger drones.
In addition to the list above I have a range of motor controllers of which only one is in Hat format.
- 3KW Universal Motor Driver
- 3KW 3-phase motor driver
- I do in addition have a smaller universal motor driver that I consider upgrading. This only cover ca 15A and is smaller not requiring specialized wiring as the 3KW one. I am a bit undecided on several issues around the Universal Motor Driver as mentioned below.
The 3KW Universal Motor Driver is cool and it’s powerfully as it can be extended with other Hat’s, but I have to consider if this is worth it. I have a new motor incoming to make it possible to test this, but to be honest motors in this category is either extremely expensive or 3-phase – and 50A is not much on a 3-Phase as I easily could need 200A on larger 3-phase drone motors. I like the universal drivers to much not to finish them at some point, but I realize that I am better off focusing on the 3-phase driver for larger motors. It is not many steppes that I can’t drive With the PWM card and even the smaller 250W Universal Motor Driver was troublesome to test. This is a very successfully and fun Project so far, but truth been said I might not have much real usage for it for now.
And lets not forget Raspberry PI that also need software once I am completed with XPortHub that I use as base SW factory.
We are talking about several test projects, but both a boat and airplane is on the agenda. Myself I really want to build an airplane-drone with VTOL capacity – basically take of and land as a drone and fly like an airplane to cover more distance. The showstopper is cost right now. I need a minimum size and that means expensive motor and frame. The boat is far more realistic.
The main challenge with these drones are that they need to be AI driven. As they get further from base communication will be limited and they need a minimum of self-contained navigation intelligence as well as sufficient AI to find their way back home.
Mentioning radio range – Lora is 868Mhz line of sight up to 12Km with a 1W Sender. I actually want to build a radio with larger range using long- or medium- wave signals. An AI based drone can manage with very low bandwidth if it can operate in automated mode only receiving commands and sending data then needed. With a long-range radio on 100Khz you can in theory radio half around the planet on a few watts. The main trouble is size on equipment and licensing to use frequencies.