Digilent Pmods: Power Pmods

It’s been awhile since we last had some specific focus on Pmods, so I decided that we should get back to our favorite blog series (or at least my favorite). This week we’re going to check out some of the Pmods that occasionally get overlooked– the power Pmods. These Pmods include screw terminal modules, transistor modules, and power monitors.

Need a Boost?

Some of the Pmods, such as the PmodOLED and the PmodCLP, need a higher operating voltage to run their screen than is normally supplied by system boards. This predicament could be solved by using an external power supply to power the screens, but that can get pretty inconvenient especially if you want your project to be portable. A slightly easier method that does not require a power supply is a boost converter circuit.

What Is the Hall Effect?

Robots that run around on motors are pretty sweet. These motors traditionally tend to be DC motors that are controlled through the use of an H-Bridge, which can change the flow of current so that the motor is able to run forwards or backwards. H-bridge modules, such as Digilent’s PmodHB3 or PmodHB5, also tend to have two pins labeled as Sensor A and Sensor B that measure which direction the motor is rotating. The two sensors, A and B, will be wired to the outputs of components known as Hall effect sensors. Unsurprisingly, these measure the Hall effect. But rather than having the “word in the definition” problem, let’s learn some of the practical details.

A Listening Calculator

When working with microcontrollers, it’s pretty straightforward to have your system board “listen” for an input that you would give it and have it do some sort of action to show that it noticed your input, such as pressing a button to light up an LED. Listening to a set of inputs and then comparing them to a predetermined set, like in the Simon Says game, is a little more involved but definitely doable. But what if we did not compare to any internal values and the system board has no idea how many inputs we might provide?

Digilent Pmods: Connector Pmods

It’s time for another Pmod feature! Today, we’re going to check out the Connector Pmods. Rather than just being strictly limited to a pure input Pmod or pure output Pmod, all of these Pmods are able to easily communicate with the system board in both directions. Although many of these Pmods might be chalked up to simple “pass-through” modules, I certainly wouldn’t label them that way. These Pmods offer some invaluable features that are otherwise not so easily obtained.

Shields vs Pmods: Good vs Better?

Today we’re going to compare two different ways of increasing the functionality of a system board: Pmods and shields. Those of you have that have been following the Digilent Blog know that Pmods are Digilent’s series of peripheral modules with 6-12 pins that can easily be connected to appropriate pins on a system board to provide extra functionality and include audio amplifiers, GPS receivers, USB to UART interface, seven-segment displays, accelerometers, H-bridges with input feedback, analog-to-digital converters, and much more. For the rest of you who have been in this sector of the electronics industry, you know that shields are a type of board that you can plug directly on top of your microcontroller in a nice pin-to-pin fashion for expanded functionality. Although you might suspect which of these two items I prefer, we’ll check out the advantages of both of them.

Running 5+ Servos on a uC32…Can I Do It?

In the not too distant past, we made a couple of posts on Pmods that can help drive motors as well as a post on stepper motors. Today, we’re going to check out running multiple servo motors on a chipKIT board. Why would we want to do this? Well, aside from the nice feeling that comes from successfully doing some extreme multitasking, we’d also be able to run some super cool mechatronics projects, such as a robot arm!

How to Read a Datasheet

Here at Digilent we have a ton of products with a large amount of documentation and examples (like our Learn site and our Instructables page) letting you know how you can use our products. Within all of these, there are statements about what each product is (and is not) capable of in addition to the recommended operating condition. Some of you may be wondering, “How do we know these things?” Much of the information presented is determined from a datasheet. But where do we find this sort of information in the datasheet, or how do we even read a datasheet? Let’s find out.