Pololu QTR-8RC sensor on RPi

We are using a Pololu QTR-8RC line following module. This sensor array has 8 IR LED/phototransistor pairs and provides a capacitor discharge that we need to time in order to work out any relative reflectance – lower values would be lighter surfaces to higher values. The sensor array is powered by 3V3 (5v default, converts to 3V3 by bypassing a …

Mr. Bit Pocket Lab – Developing on RPi3 using Android

Time is against us, PiWars 2017 is less than 5 weeks away. We didn’t realise that building a robot would be so involved. We need every minute we can find to work on Mr Bit and with travel and weekends away scheduled we’re going to need to use any downtime whilst not at home (on the train etc) to continue …

Bluetooth Comms between RPi3 and Android

As users of shiny technology we have become used to connecting devices to bluetooth and the routine for doing this – it’s easy, right? That’s because the developers of these technologies, quite rightly, have hidden away the complexity behind the scenes making it straightforward for us users. Whilst developing our robot we’ve uncovered some of the bluetooth complexity and learnt …

Pi Takes Control of the Monster

Now we have the GrovePi we can interface the Pi with the Sparkfun Monster Moto shield so the Pi can control the motor driver. Before hooking up the motor driver to the shield Reb and I needed to confirm which inputs on the Monster Moto operated which motors, Sparkfun’s sketch gave us some clues but we wanted to be certain. Using …

GrovePi Arrival and Test

The GrovePi+ arrived at the weekend! Dexter Industries have written a few Pi client libraries in different languages to make use of the GrovePi’s ATmega328. We’re going use the Python library which has functions similar to those seen in wiring such as digitalWrite(pin, val) and analogWrite(pin, val). This is great because we are not writing wiring code that compiles and …

5V GPIO, PWM and ADC on Raspberry Pi

This is a long post, I’m sure most will stop after the “too long, didn’t read” section but if you’re looking to interface 5v sensors, multiple PWM outputs and multiple analog inputs to the Raspberry Pi with a simple interface and code ready to go then read on. TL;DR; Pi does not have 5V GPIO, >1 PWM, Analog ports/pins but …

post it notes with list of to do

Product Management – Child’s Play

Living some distance away from each other Rebelle and I need to collaborate and share plans whilst working on Mr. Bit.  We were writing down our lists of things to do and going over them trying to discuss them and prioritising what we need to do next but it became difficult to synchronise our lists and understand what each other was …

monster moto driver on arduino with batteries and motors connected via crocodile clips

Controlling A Monster

We have chosen to use a monster moto motor driver for Mr. Bit.  This driver is an Arduino shield format and the control of it is direct from a seeeduino.  We wanted to test the motor driver with a simple keyboard input to drive the motors backward and forward.   Firstly we had to solder the connector headers, we decided to swap the connectors for …

Some Bits To Start With

We’ve got our electronics ready for our robot, Mr. Bit. Firstly, as it’s “Pi”Wars then a Raspberry Pi must be at the core of the robot and be the master controller to the rest of the electronics.  We will need motors so he can move around and motor drivers to power them.  There are two batteries, the first is a …

Rebelle looking at pi wars on laptop

Pi Wars – Mr Bit Team Online

Rebelle (my daughter – that’s her handle for the web) and I have been planning to attend PiWars and have been scratching at moments to put our thoughts together on our robot.  We don’t have much time together, a few days every month and so we’ve been discussing over the phone most weeks about what we should do and how we …