alex

Alex Eames is the founder, owner and main contributor to RasPi.TV more information about him can be found in his Google+ profile.

Feb 032016
 
Using MCP3008 to measure temperature with GPIO Zero and RasPiO Pro Hat

In the previous article I showed you the GPIO Zero Experimenter’s Kit I put together to go with the RasPiO® Pro Hat. Today I’m going to give a quick overview of how to use the MCP3008 analogue to digital converter to read the TMP-36 temperature sensor. This gives us a temperature reading (in °C) that we can use to make “decisions” in our Python program. In our case, we’re going to switch on a red LED when the temperature is 24 °C or greater. But there are all sorts of other things you could do, […more…]

Jan 282016
 
GPIO Zero Experimenter's Kit and RasPiO Pro Hat

On Tuesday I had a funny thing happen. I was testing an analogue to digital converter (ADC) chip – the MCP3008 – to see how well it worked on the RasPiO® Pro Hat. I had it all wired up, and powered up the Pi, typed a few lines of GPIO Zero code, and… It worked, but not quite how I thought it should. Instead of giving a value of 1.0 for 3V3 and 0 for 0V it was giving 0.67 for 3V3. I left it running and went for lunch. During lunch the ‘lights went […more…]

Jan 152016
 
RasPiO Pro Hat  - Putting Pi Ports in Perfect Positions for Productive Play

Today I launched the RasPiO Pro Hat on Kickstarter. It’s a Raspberry Pi Hat for GPIO tinkering (it goes perfectly with GPIO Zero). It arranges the GPIO ports in numerical order around a mini-breadboard, which, to my knowledge, has not been done before. It also replaces the RasPiO Breakout Pro (now end of life) because it protects all the ports from over-current and over/under-voltage as well. It should prove a very useful board for GPIO tinkering and education. Have a look at the video and pop on over to the RasPiO Pro Hat campaign page […more…]

Jan 072016
 
Always Test Everything - Twitter App Update

I’m a firm believer that you should always test things in advance. It helps avoid unexpected last-minute panics when things don’t work as you expected them to. On Friday I’m going to pick a winner from my twitter followers using the twitter app script I wrote back in October 2013. My Joey from @gooligumelec just arrived. :) I have a spare I will give to a randomly selected follower on Friday. pic.twitter.com/yGtwATYXng — RasPi.TV (@RasPiTV) January 5, 2016 It Still Works, But… Since I had no idea where the SD card with that old Raspbian […more…]

Dec 022015
 
Ethernet On Pi Zero - How To Put An Ethernet Port On Your Pi

The Pi Zero attracted a huge amount of attention, which is great for the educational mission of the Raspberry Pi Foundation. Whenever a new product is released, people air their opinions in the forums on what they would have liked it to have. One of the most common “I wish it had”s was an ethernet port. There are reasons why ethernet was not included. The two most obvious ones are cost and board size (it would have almost doubled the size of the Zero) So What’s To Be Done If You Need Ethernet? Well the […more…]

Nov 302015
 
Raspberry Pi Zero - Updated Pi Family Photo

With each new release of Raspberry Pi, I usually do a new family photo. It’s getting harder and harder to fit them all ‘on the sofa’ and get them all smiling. The way I’ve always done it is “all in one shot”. I may change this for future versions in order to get more definition. We’ll see. (As usual, more ideas than implementation time.) I am very happy for people to use this photo if they wish to do so provided the RasPi.TV credit stays intact. I make it available at 1500px resolution as CC-BY-SA. […more…]

Nov 272015
 
Raspberry Pi Zero - Power Measurements

Since the Pi Zero is small and eminently wearable, I thought I’d take some power measurements as this will be useful information for people to plan their projects. So I ran my usual series of tests and updated the table and chart showing all consumer models of Raspberry Pi. In my standard tests, I measure the current consumption, using the calibrated shunt on my Emeter, while the Pi is: Idling; Loading LXDE; Watching HD video and Shooting HD video. Since the Zero has no camera port, shooting video is not applicable, but all the other […more…]

Nov 262015
 
Raspberry Pi Zero FREE on the cover of this month's MagPi magazine.

Raspberry Pi Zero FREE on the cover of this month’s MagPi magazine. Yes you read that correctly. Raspberry Pi have pulled another world first out of the bag. Back in the pre-internet days when I used to buy PC magazines, they used to have a cover disk. Well Raspberry Pi have come up with a ‘cover computer’. It’s an absolutely awesome idea and is sure to cause ‘quite a stir*‘. Raspberry Pi Zero, a brand new spin of the Raspberry Pi, is designed to be as inexpensive as possible. A year ago the model A+ […more…]

Nov 182015
 
7 segment display Python Raspberry Pi - countdown ticker

Continuing with our theme of 7-segment displays driven directly from the Raspberry Pi’s GPIO using Python, I was asked for an explanation of the code from the previous post. In order to explain something, you first have to fully understand it, so I took some time to have a good look at the ‘business end’ of Bertwert’s code and figured out exactly how it works. I’ve now put a full code walkthrough of that script in the comments section of the previous post. Having done that, and having had a tweet from David Meiklejohn saying […more…]

Nov 162015
 
How to drive a 7 segment display directly on Raspberry Pi in Python

Last week I bought some 4-digit, 7-segment displays to experiment with. Strangely enough it was something I’d never tried before, so I was interested to see how they work. I googled around looking to see if someone else had done this before. It seems there are several different sorts of 7-segment displays, so you have to find a good match for the one you’ve bought. You can get them in various guises including: i2c backpack; 12 pins; 16 pins; resistors built-in; common anode; common cathode etc. The ones I bought are 12 pin, bare, no […more…]