Setting up RPi MIDI #2

July 27, 2017

In a previous post on setting MIDI baud-rates on the RPi I used a slight of hand (i.e. init_uart_clock etc.) to trick the RPi in setting the UART to a 31250 baud needed for MIDI. While browsing the Raspberry Pi forum I spotted this nugget of information from PhilE:

in config.txt add:

enable_uart=1
dtoverlay=pi3-miniuart-bt
dtoverlay=midi-uart0

 

This combination does three things:

1) Enables the UART. It isn’t strictly necessary when combined with pi3-miniuart-bt
2) Reassigns the weaker UART (ttyS0) for Bluetooth and frees ttyAMA0 for our MIDI interface
3) Using an DT overlay to achieve the same UART clock settings as our init_uart_clock etc. trick

It makes things a lot simpler 🙂

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Zero MIDI

December 26, 2016

A quick teaser for my next Raspberry Pi MIDI project:

 


Raspberry PI – FieldBus CAN/RS485/RS232 add-on board

November 22, 2016

Despite USB being everywhere, I still use a lot of industrial and embedded interfaces, such as RS232 and RS485 interfaces, in my projects. Legacy equipment especially and even new industrial equipment still use RS232 for programming and monitoring. While RS485 interfaces can still be found a lot in industrial communications such as factory automation.

So with this in mind I felt I needed an Raspberry Pi add-on board to simplify a lot of these connections. So here is the Raspberry PIIO FieldBus add-on board. It is a multi-communications board RS232 or RS485 and CAN Bus interfaces.

rpi_piio_fieldbus1_small
The board uses 3.3V components and is completely voltage compatible with the Raspberry Pi.

The board connects directly to the Raspberry Pi’s SPI to provide CAN Bus communications and also to the UART Rx and Tx to provide RS232 or RS485 communications.

CAN Bus interface uses MCP2515 CAN controller and MCP2551 CAN transceiver IC provides CAN Bus v2.0 A/B at 1 Mb/s. It is connected the Pi’s SPI Interface. Connection is provided via a 3-Way screw terminals.

RS232 interface uses a 3.3V MAX3232 (or Equivalent IC) chip and CTS (GPIO16) & RTS (GPIO17) signals are provided. Connection is provided via an industry standard 9-Way D Connector (Male).

RS485 interface uses 3.3V MAX3485 (or Equivalent IC) chip with DE (GPIO27) & !RE (GPIO22) used to control the RS485 transceiver control signals. Connection is provided via a 3-Way screw terminals to the outside world.

The Raspberry Pi expansion port has only on UART interface available for serial communications. So where both circuits are fitted, only one RS232 or one RS485 interface may be connected to the UART, therefore only one interface can be used at any time.

You can find them on our Tindie store


Relay2 – new Raspberry Pi Zero add-on board

September 29, 2016

Relay2 is my latest RPi Zero add-on board. It’s designed to control low voltage and small-ish current devices such as DC motors, servos etc.

rpi0_piio_relay2_small

Relay2 is a 2-ch Relay board with two Change-Over (CO) relays. Each relay is good for 30V AC/DC at 1A. The relays can handle a greater voltage than 30V but given the close proximity of the actually RPi Zero board I would not recommend going above 30V. The relays are easy to select via GPIO headers and they use 3-way Screw Terminals.

You’ll find them on our Tindie store real soon.


Two new Raspberry Pi Zero add-on boards

August 30, 2016

I’m very pleased to show off our latest Raspberry Pi Zero add-on boards.

RPio_PIIO_ADC16_UserP0rt_small

The board in the top of the picture is PIOO UserP0rt which features a 16-ch port expander and 8-ch ADC using the MCP23S17 and MCP3008 ic’s.

While the board in the bottom of the picture is PIIO ADC16 which is a 16-ch ADC board and features 2x MCP3008 ADC’s (each 8-ch, 10-bit).

You’ll find them on our Tindie store real soon.


WIP – new RPi Zero add-ons

June 29, 2016

This last month I’ve been working on some new add-on boards for the Raspberry Pi Zero.

In no particular order:

  • ADC16 – 16-ch ADC board (2x MCP3008 8-ch, 10-bit)
  • UserP0rt – 16-ch port expander and 8-ch ADC (MCP23S17 and MCP3008)
  • Relay2 – 2-ch Relay board (2x Relays 30V, 1A)
  • I’ve just sent these off to be manufactured, so I’ll post an update when I’ve got them back.


    R-Kade Mini pictures

    May 30, 2016

    It’s been a while since I last wrote about R-Kade Mini so I thought I would share a couple of new-ish pictures. These were taken at Maker Faire UK in April.

    R-Kade Mini Makerfaire2016-small

    Instead of painting the cabinet I used black clothes dye instead. I’m please to report it work much better than I thought it would, giving it a nice flat black finish with no brush marks or paint smears. The decals were a mix of ones I printed off and some I bought off ebay. All in all I very pleased how it all turned out.

    R-Kade Mini & Zero Makerfaire2016-small