I am going to talk a little bit about the Pmod pack available from Digilent. At the time of this post the Basys 3 Pmod pack is available from Digilent for $45 USD. So I recently decided to acquire the Pmod pack as a companion to the Basys 3 development board.
What is a Pmod?
I strongly suspect that Pmod is simply short-hand for peripheral module. So a Pmod is an add-on board that expands the set of peripherals we can access from the Basys 3. Digilent has created a standard interface specification for Pmod devices, you can find the full spec here. The existence an established standard is very convenient and should allow both Digilent and 3rd parties to create new and interesting add-on peripheral modules over time. And who knows, if I get really adventurous down the road I may create a simple Pmod board of my own to explore different kinds of peripherals.
The Digilent Pmod interface is used to connect low frequency, low I/O pin count peripheral modules to
host controller boards. There are six-pin and twelve-pin versions of the interface defined.
What do you get in the Pmod pack?
The Pmod pack includes a set of 5 add-on peripheral boards designed to work with the Basys 3 FPGA development board. The Basys 3 has 4 Pmod headers so you can plug in multiple boards at the same time. This should provide plenty of opportunity to explore peripherals beyond those provided on-board the Basys 3.
The Pmod back includes five modules:
- Ambient light sensor module
- Audio amplifier module
- 16-button keypad module
- A 128 x 32 pixel mono OLED display module
- A resistor ladder digital-to-analog (D/A) converter module
What can we do with Pmod modules?
I am still thinking of all sorts of ideas for how we could use these modules in the future. But here are just some of my early thoughts. With the light sensor we can detect whether room lights are on or off. And the amplifier module can detect and possibly even analyze audio signals. While the D/A converter can potentially generate 8-bit sound effects. The keypad module will allow for some interactive control. And the OLED display will allow us to have a clearer and much richer view into what is happening inside our FPGA device.