My Raspberry Pi B+ arrived last week. So far not had much time to do anything with it but like the improvements I’ve seen so far.
I design my first Pi MIDI interface way back in 2012 while I was waiting for my first Pi board to arrive.
It’s went through several revisions since then and now looks like this:
The circuit is now completely 5V as per the original MIDI specification but the MIDI IN is 3.3V compatible with the Pi via a voltage divider circuit.
OK that’s the hardware what about the software?
Getting a MIDI 31250 Baud Rate on a Pi is not easy as it should be as 31250 is not a standard Pi baud-rate. But you can trick your Pi into it if you overclock (or rather underclock) the UART clock.
Start a terminal session and type:
sudo nano /boot/config.txt
Add these lines to the end of the file
# Change UART clock to 2441406 for MIDI 31250 baud rate init_uart_clock=2441406 init_uart_baud=38400
save and exit.
Once saved reboot your Pi.
Next we need to stop the serial UART being used by Raspbian for the shell console. Check my previous post “MiniPIiio RS232 set-up” on how to do this.
Finally we need to add the following to “cmdline.txt”
After doing all of this we should be ready to connect a MIDI keyboard or synth to our Pi.
Again I hope to have it stocked in out our store on Tindie soon:
Here’s a photo of a finished RPi-X PIAC experimenter module:
PIAC = Pi Industrial Automotive Controller
It’s a Pi expansion shield that has 4x Change Over (CO) relays, 4x Opto Isolated Digital inputs and 4x 0V to 10V Analogue Inputs. There’s also a RS485 interface to communicate with industrial networks.
You can use it to learn about industrial control or perhaps even use it on your own small control projects.
I hope to have it stocked in our Tindie store soon:
Saturday’s postman delivered my first RPi Compute Modules and IO board.
I didn’t have much time to do any thing with it except marvel at compact it is.
I hope to take some pictures in the next day or two and post them.
I’ve some cool ideas for what I’m going to make with it so pop back soon.
Another box of new boards arrived from DirtyPCBs.com today.
In the box where 4, yes 4 sets of PCB’s.
In the photo, the big PCB at the back is RPi-X PIAC. On the photo front row, on the left is MiniPiio LED Breakout, in the centre is MiniPiio BOP4 and to the right is MiniPiio PWM16
RPi-X PIAC is our latest RPi-X experimenter board. The acronym IAC is commonly used to describe an industrial automation and control system and adding a P in this case makes it a Pi Industrial Automation and Control :-)
PIAC has 4x SPCO Relays rated at 2A, 4x opto-isolated digital inputs, 4x 0-10V Analogue inputs and finally a RS485 communications port. So with the RPi-X PIAC you can learn about industrial control or perhaps use it for your own small industrial project.
MiniPiio LED Breakout uses the popular MAX7219 8-digit (64x LED) LED display driver chip to breakout all 64 LED outputs to 8 rows of pin headers. From these pin headers you can plug in individual LED’s to make whatever LED display layout you want. It’s a shame its not Christmas as I think it would make a great blinky LED Christmas tree :-)
MiniPiio BOP4 or Board of Pots (or should that be “Bored of Pots”) has 4 potentiometers (3x rotary and 1x slider) and connects them to a 4-ch MAX3004 ADC. I think it will a great physical user interface. It’ll probably make a great companion to the LED/Switch MiniPiio SimpleIO we showed off a few months back. Of all the new boards I think this is my favourite :-)
The final new PCB, is MiniPiio PWM16. I think its name gives it away. It’s a hardware based 16-channel PWM add-on board using the popular PCA9685.
As always you’ll find them on my Tindie store in the next few days.
A new batch of PCB’s arrived today.
There were two new Raspberry Pi add-on boards in the box.
The first board is a 2-channel Type-K Thermocouple converter based on the MAX31855 chip.
The second board is RF Transceiver based of HopeRF popular RFM12B module.
I’ll plan to build them up in the next few days and if all goes well I’ll list them in our Tindie store.