Mikroe

MikroElektronika has a collection of base boards and small accessory boards, Click, that connect by the mikroeBUS.

The mikroBUS connector is has two rows of 8-pin 0.1" pitch headers. The Click boards can be approximately this size, or much longer if more space is needed.

Both the Feather and Gen 3 M.2 SoM Click shields have two mikroeBUS sockets.

  • SPI (SCK, MOSI, MISO) is shared on both sockets, however each socket has its own CS pin (CS1, CS2).
  • I2C is shared on both sockets, but I2C is designed to be used that way.
  • Serial is shared on both sockets, but you can generally use only one for serial, unless the serial is unidirectional from the MCU
  • Logic levels must be 3.3V to interface with the Argon, Boron or B Series SoM!
  • The mikroeBUS socket has both 3.3V and 5V on it.
  • The RST1/RST2 pin is used by some click boards to reset the click board. It is unrelated to the nRF52 MCU RST line.

There are a very large number of Click shields available, however there is no set of available libraries like the Sparkfun Qwiic line. One reason is that the Mikroe line is designed around generic ARM processors, not Arduino. While the Arduino library system is different than Particle, the translation is very straightforward and was automated. There currently is no automatic translation of Mikroe libraries to Particle so they need to be done by hand.

For some sensors, for example the TMP102 I2C temperature sensor, there is a library available in the Particle community libraries.

Feather Shield

Mikroe Feather

The Feather Click shield has sockets for an Argon or Boron, as well as two Click boards.

Unlike the Adafruit Feather tripler, certain pins (AN, RST, CS, PWM, and INT) are different for each mikroBUS connector.

The Feather pins map to mikroBUS as follows:

Feather mikroBUS1 mikroBUS 2
RST NC NC
3V3 +3.3V +3.3V
MD NC NC
GND GND GND
A0 AN1 NC
A1 NC AN2
A2 RST1 NC
A3 PWM1 NC
A4 INT1 NC
A5 CS1 NC
SCK SCK SCK
MOSI MOSI MOSI
MISO MISO MISO
RX RX RX
TX TX TX
NC NC NC
EN NC NC
USB +5V +5V
D8 NC PWM2
D7 NC RST2
D6 NC INT2
D5 NC CS2
D4 NC NC
D3 NC NC
D2 NC NC
SCL SCL SCL
SDA SDA SDA

This table just shows the socket-specific pin mapping:

mikroBUS Feather
AN1 A0
RST1 A2
PWM1 A3
INT1 A4
CS1 A5
AN2 A1
RST2 D7
PWM2 D8
INT2 D6
CS2 D5

Gen 3 SoM Shield

Mikroe Gen 3 SoM

The Gen 3 SoM shield connects a B Series SoM to mikroeBUS Click boards:

M.2 Pin Generic SoM Gen 3 mikroeBUS #1 mikroeBUS #2
20 SCL D1 SCL SCL
22 SDA D0 SDA SDA
23 ADC0 A0 RST2
33 ADC1 A1 AN1
35 ADC2 A2 AN2
36 TX TX/D9 TX TX
37 ADC3 A3
38 RX TX/D10 RX RX
41 ADC4 A4
43 ADC5 A5
45 ADC6 A6
47 ADC7 A7
48 CS D8 CS1
50 MISO MISO/D11 MISO MISO
52 MOSI MOSI/D12 MOSI MOSI
54 SCK SCK/D13 SCK SCK
62 GPIO0 D22 INT1
64 GPIO1 D23 INT2
66 PWM0 D4 CS2
68 PWM1 D5 PWM1
70 PWM2 D6 PWM2
72 PWM3 D7 RST1

This table just shows the socket-specific pin mapping:

mikroBUS Feather
AN1 A1
RST1 D7
PWM1 D5
INT1 D22
CS1 D8
AN2 A2
RST2 A0
PWM2 D6
INT2 D23
CS2 D4

Example

Gen 3 SoM Shield with TMP102 temperature sensor

This is a simple example that uses the Thermo-3-click temperature sensor.

  • It uses I2C to communicate with TMP102 temperature sensor running at 3.3V
  • I2C Address 0x48. Can be reconfigured to 0x49 by moving a 0-ohm resistor
  • The INT pin is an output from the TMP102 to indicate a temperature alarm

The INT pin on each Click board is wired separately to the MCU. The Particle pin is as follows:

Shield Socket INT Pin
M.2 SoM #1 D22
M.2 SoM #2 D23
Feather #1 A4
Feather #2 D6

Using the INT pin for a temperature alarm is optional, however the example uses this feature.

Here's the code

   

Be sure to add the SparkFunTMP102 library to your project, such as by using Particle: Install Library in Particle Workbench.

The USB serial debug log might look something like this:

0000080001 [app] INFO: tempF=73.1
0000090001 [app] INFO: tempF=73.1
0000100001 [app] INFO: tempF=73.2
0000104373 [app] INFO: temperature alarm triggered
0000110001 [app] INFO: tempF=75.2
0000120001 [app] INFO: tempF=74.1
0000126260 [app] INFO: temperature alarm cleared
0000130001 [app] INFO: tempF=73.8