The aim of this pcb is to offer an easy way to build a reliable and compact battery powered multi-sensors based on MySensors, an ATMega328P (Arduino) and a RFM69 or NRF24 radio module.

This pcb is designed to provide the following functionalities:

  • Motion detection (PIR AS312)
  • Light level detection (Photoresistor)
  • Temperature detection (Si7021)
  • Humidity detection (Si7021)
  • Motion, Power and radio activity signaling LEDs, configurable in the firmware

The board can be powered in different ways:

  • 2 x AAA batteries (Rechargeable or Alkaline)
  • 1 x CR2032 battery
  • At 5V through the micro USB connector
  • At any DC voltage between 5V and 12V through the connector J6 (2.54 mm PIN header)

The board supports different radio modules:

  • RFM69 radio module
  • NRF24 radio module THT version
  • NRF24 radio module SMD version

The flexibility in the battery type usage is possible, among to other things, thanks to this boost converter that increase the voltage to 3.3V when the battery voltage goes below 2.7V, which is the minimum voltage required by the PIR AS312 to work properly.

The schematic and the entire Kicad project are available for download in the dedicated d-diot github repository. In the repository, here you can find the gerber files of the PCB, so you can easily get 10 boards with about 5€ using an online PCB manufacturer like JLCPCB or PCB way. Click the button below to download the complete set (zip) of gerber files necessary for the manufacturing of the latest version of the board available.

Download Gerber BT-Pcb-328P v.3.0

This is how the board looks:

Below the schematics ( pdf format).

BT-Pcb-328P Schematics

Use the interactive BOM tool to see where to place each component

Visit the dedicated topic in the forum if you need to know more.

The main features of the pcb are:

  • Small dimensions: 57 x 57 mm
  • Multiple power options: 2 x AAA batteries (Rechargeable or Alkaline), 1 x CR2032 battery or standard cellphone charger at 5V through the micro USB port
  • Reverse polarity protection (Mosfet Q1) to prevent damages in case of wrong batteries insertion.
  • Boost converter (ME2188C33) to increase the battery voltage to 3.3V when necessary
  • LEDs for radio traffic, low batteries and motion detection signaling. All configurable in the firmware.
  • Multiple radio module supported: NRF24L01 (SMD and THT) and RFM69.
  • Socket for the Si7021 Temperature and Humidity.
  • Socket for the AS312 Pir motion sensor with mounting holes for a standard Fresnel lens like the one used in the HC-SR501 motion sensor.
  • Socket and circuit for a photoresistor to measure the light level
  • Additional PIN to power the board (J6)
  • FTDI and ICSP headers to program the MCU
  • Support for ATSHA204 chip (security and signing)
  • Mounting hole for a M2.5 screw
References Value Footprint Quantity
C1 22uF-Tantalum CAPPC3528X210N 1
C14 47uF CP_Elec_5x5.4 1
C13 100uF CP_Elec_6.3×5.4 1
C3 C4 C5 C6 C7 C10 C11 C12 0.1uF C_0805_2012Metric 8
C2 C9 10uF C_0805_2012Metric 2
C8 100uF-Tantalum TAJD107K016RNJV 1
R1 R2 R4 R9 10K R_0805_2012Metric 4
R8 R11 R12 R13 330 R_0805_2012Metric 4
R3 R5 20K R_0805_2012Metric 2
R7 56K R_0805_2012Metric 1
R10 120 R_0805_2012Metric 1
R6 R_PHOTO R_LDR_5.0x4.1mm_P3mm_Vertical 1
L1 22uH L_6.3×6.3_H3 1
D4 D5 Y-LED LED_0805_2012Metric 2
D2 R-LED LED_0805_2012Metric 1
D3 B-LED LED_0805_2012Metric 1
D6 G-LED LED_0805_2012Metric 1
D1 SS14 SS14 1
U7 NRF24L01 NRF24L01 1
U8 NRF24L01 NRF24L01-SMD 1
U2 AS312 PIR-AS312-3PIN 1
U4 RFM69HW RFM69HW_SMD_ThroughHole_Handsoldering 1
U1 AMS1117-3.3 SOT-223-3_TabPin2 1
U5 ME2188C33 SOT-23-5 1
U6 ATSHA204A SOT-23_Handsoldering 1
U3 ATmega328P-AU TQFP-32_7x7mm_P0.8mm 1
SW1 SW2 1437566-3 SW_1437566-3 2
BT1 BT2 AAA Cell AAA-Keystone-5204-5226-NO-SILK 2
BT3 CR2032 BatteryHolder_Keystone_1058_1x2032 1
Q2 Q3 Q6 FDN337N SSOT-3 3
Q1 FDN338P SSOT-3 1
G*** LOGO d-diot-logo-small 1
J4 ANT PinHeader_1x01_P2.54mm_Vertical 1
J6 Vin PinHeader_1x02_P2.54mm_Vertical 1
J5 Si7021 PinHeader_1x04_P2.54mm_Vertical 1
J3 ICSP PinHeader_2x03_P2.54mm_Vertical 1
J2 FTDI PinSocket_1x06_P2.54mm_Vertical 1
J1 USB_B_Micro USB_Micro-B_Molex-105017-0001 1
P1 MYSX_2.6 MYSX_2.6 1

The BT-Pcb-328P-firmware is available as a PlatformIO porject in the d-diot github repo.

Follow the firmware upload guide to know how to flash your board with PlatformIO directly from your d-diot hub.

The configuration of the firmware is in the following files:

For each parameter, see the comments in the files.

Visit the dedicated topic forum if you need to know more.

  • hardware/pcb/mysensors/bt_pcb_328p.txt
  • Last modified: 2019/11/26 20:10
  • by franzunix