Alex Eames (from RasPi.TV) gave me one of his new boards to take a look at. It’s called the RasPiO Analog. It gives you the ability to add analog inputs to your Raspberry Pi. It’s essentially a GPIO plugin prototyping board with an MCP3008 analog-to-digital converter chip onboard.
It has the following features:
- All the useful GPIO pins broken out into at least one group of pins.
- The entire GPIO broken out into a double row so you can add a box header and a ribbon cable if you want to add another GPIO board (probably via ribbon cable).
- An LED so you can tell it’s on and working properly.
- The MCP3008 chip, which gives 8 analog input channels.
- The 8 channels broken out twice.
- A large prototyping area with rails for 3v3, ground and 5v.
- Some additional mini-rails for power and ground.
Here’s the bare board:
And here’s a pic of the full contents of the kit:
It’s a very simple soldering job – it would be easy enough for a beginner to do as the components are well-spaced. As always, the most difficult bit is the 26-way header for the GPIO pins.
And here’s a picture of everything soldered together:
After having assembled it I thought to myself: What can I do with it? I need to get some analog sensors. Well, fortunately, I had a load of light dependant resistors so I could use them.
So, I looked up how to do it and found this page on Raspberry Pi Spy which shows how to hook up an LDR. I also used the code from that page to interface with the MCP3008 chip to get readings. Straight away I got readings and, by placing my hand over the LDR the readings went up or down accordingly. It worked flawlessly.
Here’s a picture of the board with the LDR & resistor soldered on.
So, what can you do with this? Well, you can solder various headers on so you can plug in various analog sensors. You can solder the sensor (as I have done above) directly onto the board. And eventually? You have a board with lots of different sensors on there – perhaps a smaller version of the Picorder.
My only (very minor) criticism is that the 3v3 and ground rails could do with being extended by one hole each, but looking at the board it might be difficult to do that with the path routing getting in the way.
If you’ve ever wanted to get into analog sensors on the Pi, this is an ideal way to do it. It gives you something which can be either permanent (by soldering directly on the board) or temporary (using headers) and there’s enough room on the prototyping area to use all 8 analog inputs.
It will be available soon! Keep an eye on RasPi.tv and RasPiO for more details on a release date.
Score: 9/10