Raspberry Pi (Beeb) UserPort HAT

November 30, 2014

Of the recent Pi boards I’ve made I think UserPort is probably my favourite. It’s a mimic of the BBC’s micros digital User Port and Analogue Port.

Back in the 80’s (gosh that sounds old) I built many electronic, robotic and other projects using the Beebs digital User Port and Analogue so reproducing their functionality for the Pi was a pleasure.

Digital I/O is provided by a I2C MCP23017 16-channel Port Expander

20W IDC Connector
1 3.3V
2 CB1
3 3.3V
4 CB2
5 GND
6 PB0
7 GND
8 PB1
9 GND
10 PB2
11 GND
12 PB3
13 GND
14 PB4
15 GND
16 PB5
17 GND
18 PB6
19 GND
20 PB7

Analogue Inputs by a 4-channel SPI MCP3004 10-bit ADC.

15W D Connector

Pin
1 3.3V
2 GND
3 GND
4 ADC CH3
5 GND
6 GND
7 ADC CH1
8 GND
9 N/C
10 I1
11 N/C
12 ADC CH2
13 I0
14 N/C
15 ADC CH0

Check my other stuff on Tindie


New add-on Pi boards – RPi-X PIAC and RPiB+ Breakout+ for sale

October 31, 2014

We’ve finally managed to find time to list two new boards on Tindie.

The first is RPi-X PIAC which is an experimenter add-on board for small industrial control projects. It feature 4x Relays (Change Over), 4x Opto-Isolated Inputs and 4x Analogue Inputs (0V to 10V). It also has a RS485 serial interface for communicating with industrial networks. You can find them here

RPi_PIAC_small

The second board is RPiB+ Breakout+ which is a breakout board for the Raspberry PI B+ I/O signals. It features 2x SPI headers, 2x I2C headers, 2x UART headers and 2x GPIO headers. It also has a prototyping area which is useful building your own circuits. It is compatible with the HAT board size and has a EEPROM (currently not fitted) for future HAT configuration. You can find them here

RPiB+_Breakout!_small


eDay3 Over for another year

September 27, 2014

Today saw the 3rd eDay technology and maker event take place at Gateshead Central Library. Wow 3 years.

Maker Space was there again with 3D Printing Raspberry Pi and Arduino projects. Over Eng’D and Polar Pong gave a new meaning to the words physical computing with a mass of stepper motors and pulleys. R-Kade my Raspberry Pi mini arcade was brought out again to entertain those people wanting a trip down video gaming history. Who would have guesses that Pacman, Galaga and Donkey Kong would still appeal the younger audience.

The local radio amateur group, Angel of the North Amateur Radio Club (ANARC) were there for the first time. They had brought various radio receivers and transceivers for us to listen too.

The local Imperial Troop from the 99th Garrison made sure no droids got lost during the days proceedings :-) The Stormtroopers, Tie Fighter pilots, Bounty Hunters and Imperial Officers made an impressive sight.

There was also Vector 76 with oculus rift, html workshops, Retro Gaming, ChromeBuild Lego sessions and drop-in maker activities from Victoria Bradbury.


RPiB+ Breakout!+

August 18, 2014

Here’s our first RPiB+ HAT compatible board Breakout!+.

RPiB+_Breakout!_and_RPiB_small

RPiB+_Breakout!_small


HATS on for Raspberry Pi B+

August 14, 2014

4 new PCB’s arrived in the post today. These are my first HAT’s (Hardware on Top) for the Raspberry Pi B+.

RPiB+_HATs_small

Top (L-R) – UserPort and Breadboard+, Bottom (L-R) – DIO32 and Breakout!+

All the boards adhere to the standard HAT size and include a ID EEPROM.

UserPort is probably my favourite. It’s a mimic of the BBC’s micros digital User Port and Analogue Port. Digital I/O is provided by a I2C MCP23017 16-channel Port Expander and Analogue Inputs by a 4-channel SPI MCP3004 10-bit ADC.

Breadboard!+ is a reworking of my earlier 170-pin Breadboard module but the extra size for a HAT PCB has allowed the inclusion of a two tactile push switches and three LED’s. As well as these, there’s also 4x Analogue Inputs using a 4-channel MCP3004 10-bit ADC.

DIO32 is a 32-channel Digital I/O board with two MCP23017 I2C Port Expanders.

Breakout!+ allows easy access to the I2C, SPI and UART interfaces and includes a small prototyping area for building circuits on.

Hope to have them on our Tindie store soon :-)


Raspberry Pi B+ arrives

July 22, 2014

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.


Raspberry Pi MiniPIIO MIDI board

June 26, 2014

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:

RPi_MiniPiio_MIDI_small

RPi_MiniPiio_MIDI_Front_small

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”

bcm2708.uart_clock=3000000

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:

https://www.tindie.com/stores/DTronixs/


Follow

Get every new post delivered to your Inbox.