April 29, 2014
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.
April 14, 2014
MiniPiio SimpleIO is just that, a add-on board with simple inputs and outputs. It features 8x LED’s and 8x tactile switches. The Pi’s GPIO4/17/18/22/23/24/25/27 are each connected to an LED and switch.
You have 8x signals you can mix and match with whatever combination of LED’s or switches your design needs. So if you need more indicators you could have say 6x LED’s and 2x switch inputs and like wise, if you need more inputs than outputs you could have 5x switch inputs and 3x LED outputs.
You can find them at our store on Tindie.
Note: LED and Switches sharing the same GPIO so are not designed to used simultaneously.
April 14, 2014
Eh? Why another prototyping board? Isn’t the CM I/O a prototyping board already?
Yes, it is. And the CMIO ProtoBoard is a prototyping board for you to build circuits directly on with can be used with the CM I/O board and Compute Module.
Same as blinking an LED is the first code you write for a new embedded system, designing a prototyping board is often the first thing I do with every new system I work with.
Why, I hear you ask?
- I want some thing I can quickly build permanent circuits with, so the days of loose wires spoiling my days are far behind.
- I want some thing that is cheap and cost effective. I want to experiment with different circuit designs, without worrying if I’ve wasting money every time I start a something new.
- I want some thing that when its built looks decent and not a heap of wire
Some of the dimensions and connector positions I’ve had to guess at but here’s a quick layout of what I’ve done so far:
April 6, 2014
MiniPiio Thermocouple is a single channel temperature measurement add-on board using Type-K thermocouples.
The MAX31855 is a sophisticated thermocouple-to-digital converter. It features a built-in 14-bit analog-to-digital converter (ADC) for thermocouple measurement. In addition it also contains a cold-junction sensor for compensation temperature sensing and correction.
The MAX31855 resolves temperatures to 0.25°C. It allows readings as high as +1800°C and as low as -270°C and exhibits thermocouple accuracy of ±2°C for temperatures ranging from -200°C to +700°C for K-type thermocouples.
- Works with any K type thermocouple
– Temperature range = -200°C to +1350°C output
– Resolution 0.25 degree
– Accuracy is ±2°C
– Internal cold junction temperature reading
– SPI bus interface
– Two SPi Chips Selects (!CE0 and !CE1)
You can find it at our Tindie store
March 28, 2014
The latest version of raspi-config allows you to enable the SPI drivers without having to edit raspi-blacklist.conf file yourself.
In LXTerminal start raspi-config by type:
Select the advance menu option and chose enable SPI devices. Exit the menu and reboot your Pi.
We’ll program our example in Python, so we’ll start by downloading the SPIdev driver library.
We can use Python Installer to get install it:
sudo pip install spidev
A quick python example is shown below:
# ADC Channel
ADCCHAN = 1
# Open SPI, use Chip Select 0
spi = spidev.SpiDev()
adc = spi.xfer2([1,(8+ADCCHAN)<<4,0])
data = ((adc&3) << 8) + adc
print ('ADC CH1 =', data)
The MiniPIIO Uses a Microchip MCP3004 (or MCP3204) which are from the same ADC familily as the MCP3008
You can find the MiniPIIO AIN4 at our Tindie store:
March 21, 2014
MiniPIIO Breakout! is our newest add-on board for the Raspberry Pi.
It breaks out (hence its name) all the Pi’s expansion I/O into four neat little groups.
UART is broken out into a 6-Way and 4-way pin header. The 6-Way is FTDI USB Cable compatable.
SPI is broken out into two 6-way headers, each with it’s own SPI chip select.
I2C is borken out into two 4-way headers.
GPIO is broken out into two 10-way headers. GPIO4/17/18/22/23/24/25/27 and 3.3V and 0V.
You can buy it at our Tindie store here
March 7, 2014
RPi-X ELab101 is the second of my RPi-eXperimeter boards.
RPi-X ELab101 is a mini electronics lab for the Pi.
It is dominated by a 170-pin bread boarding area for prototyping and construction your circuits on. Next to this, there are 3x tactile switches, 3x LED’s, 2x potentiometers and a buzzer circuit which make up the input and output devices. These are connected to female headers allowing them to be quickly interfaced with the Pi’s GPIO’s using simple male-male jumper wires.
For analogue measurements, a 4-channel 0V to 10V, 10-bit ADC is included and it’s inputs are also available via a female header connector.
Finally, all the signals from the Pi’s expansion header are brought out to female headers, giving access to all the Pi’s expansion signals, including the GPIO’s, SPI, I2C, UART and PWM.
More to come….